Short implant in limited bone volume.pdf

7/24/2019 Short implant in limited bone volume.pdf

1/25

Short implant in limited bonevolume

DA V I D N I S A N D& F R A N C K R E N O U A R D

Introduction

Rehabilitation of severely resorbed jaws with dental

implants remains a surgical and prosthetic challenge

for clinicians (25, 53). Several advanced surgical tech-

niques have been developed over the years to restore

bone volume, allowing the placement of dentalimplants and improving esthetic outcomes. The same

surgical techniques have also been applied to

improve crown-to-implant ratios, to allow the place-

ment of longer implants and to optimize the position-

ing of implants for adequate load distribution.

However, the latter indications remain controversial,

and the increased treatment time, cost and risk of

complications should be analyzed in line with the

expected benets.

Sinus lift elevation, guided bone regeneration,

onlay bone grafting, distraction osteogenesis and dis-

placement of the inferior alveolar nerve were devel-

oped and applied for the management of reduced

alveolar bone height. Some of these techniques, such

as sinus lift elevation, are supported by a large num-

ber of publications and display excellent survival rates

for dental implants (18). On the other hand, less data

are available for surgical displacement of the inferior

alveolar nerve, vertical augmentation or distraction

osteogenesis (26, 94, 107). Moreover, long-term fol-

low-up studies of dental implants placed in aug-

mented bone are not available for each technique.

Even for the well-documented technique of sinus liftelevation, it should be remembered that the best

results, obtained with rough surface implants and

biomaterial, are based only on short-term follow-up

studies (87).

Complex surgical techniques are often associated

with complications (42). Complications may occur

during surgery (such as bleeding (Fig. 1), perforation

of the Schneiderian membrane (Fig. 2AD) or nerve

injury) or postoperatively (including transiently or

permanently altered mandibular sensation (25), graft

and/or membrane exposure (Fig. 3), infections (122)

and increased peri-implant bone loss (88)). Even

when the risk for complications is limited, advanced

surgical techniques may be contraindicated in some

patients for medical or anatomic reasons. As an alter-

native to complex surgeries (those performed to allowthe placement of longer implants or for biomechani-

cal reasons), the use of dental implants with reduced

length should be considered. Along with their sim-

plicity, short-length implants allow for less expensive

and faster treatment with reduced morbidity (43, 44).

However, both survival rate and indications are still

controversial. In the past, short-length implants were

often associated with increased failure rates (125),

which were explained by reduced implant primary

stability and bone-to-implant contact, as well as by

unfavorable crown-to-implant ratios. As a conse-

quence, the use of short-length implants was mainly

restricted to rescue situations.

The purpose of this review was to evaluate the data

available on the survival rate of short and extra-short

implants and to discuss the impact of an increased

crown to implant length ratio on biological and tech-

nical complications. Indications and clinical proce-

dures for short-length implants in clinical practice are

also reviewed, along with a discussion on the selec-

tion of the implant length. The paper also introduces

a new concept in implant dentistry: stress-minimizing

surgery.

Denition

There is still some controversy over the exact deni-

tion of a short-length implant. According to Striezel

& Reichart (112), an implant of 11 mm is consid-

ered as short, whereas Tawil & Younan (114) stated

that an implant must be 10 mm to be regarded as

72

Periodontology 2000, Vol. 66, 2014, 7296 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Printed in Singapore. All rights reserved PERIODONTOLOGY 2000


2/25

short. In one recent systematic review (116) and in

one recent meta-analysis (89), all implants of


3/25

performed with either a retrospective or a prospective

design (Table 2). Among this group of publications,

there is great discrepancy in the denition of a short

implant. Some authors only included implants with a

designed intrabony length of

8 mm, whereas othersincluded longer implants (13, 32, 33, 54, 103, 110, 114,

119).

One of the rst case series with a special emphasis

on short-length implants was published by Texeira

et al. (119). They followed 67 implants, with a mean

length of 8.3 mm and placed in the posterior mandi-

ble, over a period of 5 years and reported a cumula-

tive survival rate of 94%. The efcacy of short-length

implants in the restoration of the posterior mandible

was also conrmed by many other authors (1, 2, 33,

37, 38, 5558, 75, 86, 114). Positive outcomes were

also reported with severely resorbed edentate mandi-bles by several authors (34, 52, 60, 110) . Friberg et al.

(52) followed 49 edentulous patients restored with

260 short implants (67 mm in length) and reported

cumulative survival rates of 95.5% and 92.3% after 5

and 10 years, respectively. In 1998, a multicenter

study, with 17 years of follow-up, was performed by

ten Bruggenkate et al. (117), who evaluated the sur-

vival rate of 253, 6-mm-long implants in a group of

126 patients. They reported a cumulative survival

rate of 94%. Of the seven implants removed, six were

located in the maxilla, and the authors recom-

mended that short implants should be used in con-

junction with longer implants in low-density bone.

The possibility of using short implants for the reha-

bilitation of the posterior maxilla was further evalu-

ated in a 2-year retrospective study (91) involving 96

short implants (of 68.5 mm) placed in 85 patients.

A cumulative survival rate of 94.6% was obtained. Sev-eral publications have also reported favorable out-

comes for the use of short implants in the posterior

maxilla (1, 2, 5, 28, 5456, 58, 74, 80). Fugazzotto

et al. (54), who analyzed the possibility of using short

implants to restore single crowns in the posterior

maxilla, reported a cumulative survival rate of 95.1%

in a group of 979 implants. The usefulness of short

implants to support single crowns in the posterior

maxillary region was also conrmed by Lai et al. (69),

with a follow-up period of 510 years. In severely

resorbed ridges, with


4/25

Table 1. Case series in which implant length was evaluated among other parameters

Authors (ref. no.) No. of patients (no.

of implants)

Follow-up, in months

(mean)

Cumulative survival

rate 10 mm, %

van Steenberghe et al.

1990 (121)

159 (558) (12) 97.5 97.4

Jemt 1991 (64) 384 (2199) 12 94.7

Friberg et al. 1991 (51) 889 (4641) From stage 1 to

connection of theprostheses

94.5 99.4

Bahat 1993 (6) 213 (732) 570 (30.3) 92.6 (Bone type IIIII)

86.7 (Bone type IV)

95.9 (Bone type IIIII)

94.5 (Bone type IV)

Jemt & Lekholm 1995

(65)

150 (801) (60) 75.8 91.8

Buser et al. 1997 (21) 1003 (2359) 1296 91.4 95

Ellegard et al. 1997 (40) 68 (124) 384

Wyatt et al. 1998 (125) 77 (230) 12144 75 95 (only 13-mm

implants were

included)

Gunne et al. 1999 (61) 23 (69) (120) 89 100 (only three implants

were included)

Lekholm et al. 1999 (70) 127 (461) (120) 93.5 91.5 (only 13-mm

implants were

included)

Winkler et al. 2000 (124) (2917) (36) 74.4 (7 mm)

87 (8 mm)

94.3 (only 13-mm

implants were

included)

Bahat 2000 (7) 202 (660) 60144 83 95

Brocard et al. 2000 (20) 440 (1022) 1284 80.3 (8 mm) 83.7 ( 12 mm)

Testori et al. 2000 (118) 181 (485) (52.6)

Naert et al. 2002 (82) 660 (1956) (66) 81.5

Stellingsma et al. 2003

(110)

60 (240) (12)

Weng et al. 2003 (123) 493 (1179) (72) 74 (7.0 mm)

81 (8.5 mm)

93.1

Romeo et al. 2004 (98) 250 (759) 1684

Feldman et al. 2004 (46) (4891) 2460 91.6 (10-mm machined

implants were

included)

97.7 (10-mm Osseotite

implants were

included)

93.8 (machined)

98.4 (Osseotite)

Nedir et al. 2004 (83) 236 (528) 1284

Herrmann et al. 2005

(63)

487 (487) (60) 78.2 (7 mm) 95.7

Koo et al. 2010 (67) 489 (521) 1260 100 95.1

Short implant in limited bone volume

75


5/25

Table 2. Case series devoted to short-length implants

Authors (Ref. no.) No. of patients (no. of

implants)

Follow-up, in

months (mean)

Implant length Cumulative survival

rate, %

Lai et al. 2013 (69) 168 (231) 6012 (86) Intrabony length 8 mm 98.7 (5 years)

98.3 (10 years)

Draenert et al. 2012 (38) (47) (44) 9 mm 98

De Santis et al. 2011 (37) 4 6 (107) 1236 8.5 and 7.0 mm 98.1

Perelli et al. 2011 (86) 40 (55) 60 7 and 5 mm 84

Gulje et al. 2012 (60) 12 (48) 12 6 mm 96

Van Assche et al. 2012

(120)

12 (72) 24 1014 and 6 mm (two

short implants and four

long implants to

support an overdenture)

One short-implant

failure

Rossi et al. 2010 (102) 35 (40) 24 6 mm 95

Anitua & Orive 2010 (2) 661 (1287) 1102 (47.9) 8.5, 7.5, 7.0 and 6.5 mm 99.3

Sanchez Garces et al.

2012 (103)

(273) 18144 (81) 10 or


6/25

Table 2. (Continued)

Authors (Ref. no.) No. of patients (no. of

implants)

Follow-up, in

months (mean)

Implant length Cumulative survival

rate, %

Deporter et al. 2001 (33) 24 (48) 8.25.3 (32.6) 9 and 7 mm 100

Deporter et al. 2000 (32) 16 (26) 636 (11 .1) 9, 7 and 5 mm (with

crestal sinus elevation)

100

Friberg et al. 2000 (52) 49 (260) 12168 (96) 7 and 6 mm 95.5 (5 years)

92.3 (10 years)Stellingsma et al. 2000

(110)

17 (68) 6097 (77) 10, 7 and 6 mm 88

ten Bruggenkate et al.

1998 (117)

126 (253) 1284 6 mm 94

Texeira et al. 1997 (119) 26 (67) (60) 11 and 8 mm 94

Bernard et al. 1995 (13) 48 (100) (36) >10, 10, 8 and 6 mm 99

Table 3. Randomized controlled trials comparing short implants and longer implants with advanced surgical proce-dures

Authors

(ref. no.)

Patients

(no. of

implants)

Mean

length of

follow-up

(months)

Area and

number of

implants

Test Control Cumulative

survival rate

Remark

Esposito

et al.

2011 (44)

60 (121) 36 Partially

edentulous

mandible

One to

three

implants

6.3 mm 9.3 mm and

vertically

augmented

bone

Test: two short

implants failed

Control: three

long implants

failed;

augmentation

procedure failedin two patients

Statistically signicantly

more complications in

augmented patients.

Short implants

experienced statistically

signicantly less bone

loss. Short implantscould be an interesting

alternative to vertical

augmentation as the

treatment is faster,

cheaper and associated

with less morbidity

Felice

et al.

2011 (48)

28 (178) 5 months

after

loading

Fully

edentulous

maxillae.

Four to

eight

implants

5.0

8.5 mm

11.5 mm Test: two short

implants failed

Control: one

long implant

failed and one

bilateral sinus

lift procedure

failed

Signicantly more

complications occurred

in augmented patients.

This pilot study suggests

that short implants may

be a suitable, cheaper

and faster alternative to

longer implants placed

in augmented bone

Felice

et al.

2010 (47)

60 (121) 12 Partially

edentulous

mandible

7 mm 10 mm and

vertical

augmentation

Test: one short

implant failed

Control: three

long implants

failed, and two

augmentation

procedures

failed

Short implants might be

preferable compared

with vertical

augmentation, reducing

the chair time, cost and

morbidity


77


7/25

vertically augmented bone. The authors reported a

similar survival rate along with increased treatment

time and morbidity for the graft group. Moreover, in

one paper (44) a signicant increase in peri-implant

bone loss was reported for longer implants. One ran-

domized controlled trial was also performed by the

same team (48) to compare the outcome of short-

length implants in the edentulous atrophic maxilla

with longer implants placed in augmented bone. Five

months after loading, similar survival rates were

reported for both techniques, with less morbidity for

the short-length implant group.

A large number of systematic reviews and meta-

analyses (Table 4) have also been performed on

short-length implants (3, 30, 62, 66, 68, 78, 79, 84,

89, 90, 92, 100, 113, 116). According to these papers,

there is fair and growing evidence that short-length

implants can be used successfully in atrophied jaws

Table 4. Systematic review and meta-analysis on short-length implants

Authors

(ref. no.)

Type of

studies

(search time)

Number of papers

included

Denition

of short

implants

Main results Main conclusions

Annibali

et al. 2012

(3)

Systematic

review and

meta-analysis

Two randomized

controlled trials and 14

observational studies


8/25


Authors

(ref. no.)

Type of

studies

(search time)

Number of papers

included

Denition

of short

implants


Telleman

et al. 2011

(116)

Systematic

review (1980

2009)

29 studies


9/25


Authors

(ref. no.)

Type of

studies

(search time)

Number of papers

included

Denition

of short

implants


Menchero-

Cantalejo

et al. 2011

(78)

Systematic

review and

meta-analysis

(20002010)

10 mm The majority of the

studies obtain a

cumulative success rate

similar to that of

longer implants (92.5%and 98.42% for

machined and rough-

surface implants,

respectively). The

studies that record

lower cumulative

success rates are later

studies that

analyze implants with

a machined surface

In view of the results

analyzed, rehabilitations

with short implants are a

reliable treatment; however,

the lack of consistency in thestudy designs as well as the

presence of bias in all of the

studies reviewed make it

difcult to analyze the data

Neldam &

Pinholt

2012 (84)

Systematic

review (1992

2009)

15 prospective

nonrandomized

studies, 11

retrospectivenonrandomizedstudies

and one review

8 mm Data on 6-mm implants

were few (Straumann

implants representing

441 out of 549implants). Branemark

implants, 7 mm in

length, comprised 1607

implants out of 1808.

Straumann implants,

8 mm in length,

comprised 2040 out of

2352 implants. Failures

varied between 0 and

14.5%, 0 and 37.5% and

0 and 22.9% for 6-, 7-,

and 8-mm-long

implants, respectively

Short implant length was not

related to observation time,

installment region, failures,

and dropouts were notspecied; subsequently, it

was not possible to perform

a meta-analysis

Raviv et al.

2010 (90)

Literature

review

Romeo

et al. 2010

(100)

Literature

review (2000

2008)

13 studies The recent literature

has demonstrated a

similar survival rate for

short and standard

implants. Older articles

have demonstrated a

lower survival rate for

short implants

The treatment planning is a

key factor for success in the

use of short implants. It can

be assumed that a careful

treatment planning can lead

the clinician to obtain a

successful rehabilitation

Kotsovilis

et al. 2009

(68)

Systematic

review and

meta-analysis(19812007)

37 studies reporting on

22 patient cohorts


10/25


Authors

(ref. no.)

Type of

studies

(search time)

Number of papers

included

Denition

of short

implants


Renouard &

Nisand

2006 (92)

Structured

review (1990

2005)

53 studies 8 mm A relatively high number

of published studies

(12) indicated an

increased failure rate

with short implantswhich was associated

with operators learning

curves, a routine

surgical preparation

(independent of the

bone density), the use

of machined-surfaced

implants and implant

placement in sites with

poor bone density.

Recent publications

(22) reporting an

adapted surgical

preparation and the useof textured-surfaced

implants have

indicated that survival

rates of short implants

are comparable with

those obtained with

longer implants

The use of a short implant

may be considered in sites

thought to be unfavorable

for implant success, such as

those associated with boneresorption or previous injury

and trauma. Whilst in these

situations implant-failure

rates may be increased,

outcomes should be

compared with those

associated with advanced

surgical procedures such as

bone grafting, sinus lifting

and the transposition of the

alveolar nerve

das Neves

et al. 2006

(30)

Structured

review (1980

2004)

33 studies 10 mm 16,344 implants were

included, of which 786

failed (failure

rate = 4.8%).

Implants 3.75-mm

wide and 7-mm long

failed at a rate of 9.7%,

compared with 6.3% for

implants 3.75-mm wide

and 10-mm long.

Finally, 66.7% of all

failures were attributed

to poor bone quality,

45.4% to the location

(maxilla or mandible),

27.2% to occlusal

overload, 24.2% to

location within the jaw

and 15.1% to infections

(an implant could be

associated with

multiple risk factors)

Short implants should be

considered as an alternative

to advanced bone-

augmentation surgeries, as

surgery can involve higher

morbidity, require extended

clinical periods and involve

higher costs to the patient

Misch 2005

(79)

Literature

review


11/25

(3, 66, 68, 78, 90, 100, 116), reducing both the need

for invasive and complex surgery (30, 89, 92, 113)and treatment morbidity (30, 92). However, there is

a tendency for increased failure rates with

machined surface implants (89, 92, 113), placement

in smokers (116) and placement in specic loca-

tions, such as the severely resorbed posterior max-

illa (113, 116) and the anterior maxilla (89). Longer

follow-up times of up to 10 years are also needed

to conrm these ndings and to evaluate the

impact of annual marginal bone loss on survival

rate (3, 92, 113).

Extra-short implants

Three case series (36, 86, 108) and one randomized

controlled trial (43) were recently performed to eval-

uate the survival rate of extra-short implants sup-

porting xed partial dentures in severely resorbed

posterior jaws. In the paper by Slotte et al. (108),

three to four 4-mm implants were inserted in the

posterior mandibles of 24 patients (87 implants in

total) to support xed partial dentures. Two years

after loading, a survival rate of 92.3% was reported.

Using a split-mouth design, Esposito et al. (43)compared 5-mm implants with 10-mm implants in

augmented bone (with either interpositional bone

blocks in the mandible or sinus lift in the maxilla)

to restore either the posterior mandible (15 patients)

or the posterior maxilla (15 patients). They report

similar outcomes for both techniques. The use of

extra-short implants allows patients to be treated

with lower cost and less morbidity. However, so far

only sparse short-term data are available. Further

studies are needed to evaluate the long-term

prognosis.

Stress repartition and crown-to-implant length ratio

A dogma (4) states that the prognosis of abutment

teeth and prosthetic rehabilitation is related to the

crown-to-root ratio. According to this statement, it is

assumed that for successful prosthetic rehabilitation

the crown-to-root ratio should always be 1. How-

ever, this statement was not supported in a recent

systematic review (72) which reported similar out-

comes for abutment teeth with or without a history of

periodontal bone loss. Nevertheless, this empirically

based crown-to-root ratio guideline is commonly

applied for dental implant-supported restorations,

frequently resulting in the placement of the longest

implant possible. In areas of reduced bone volume,

in which short implants must be placed, bone resorp-

tion is often accompanied by increased maxilloman-

dibular space, with the prosthetic consequence of

excessive crown height (Fig. 5). In such sites, clinicians

tend to perform advanced surgical procedures toallow the placement of longer implants, thus lowering

the crown-to-implant ratio. According to the deni-

tion provided by Blanes et al. (16), two types of

crown-to-implant ratio can be established: the ana-

tomical crown-to-implant ratio, in which the transi-

tion line is located at the level of the implant

shoulder; and the clinical crown-to-implant ratio, in

which the transition line is located at the level of the

bone crest.


Authors

(ref. no.)

Type of

studies

(search time)

Number of papers

included

Denition

of short

implants


Hagi et al.

2004 (62)

Structured

review (1985

2001)

12 7 mm Machined

surface implants

experienced greater

failure rates than did

texturedsurface implants.

With the exception of

sintered porous-

surface implants, 7-

mm-long dental

implants appear to

have higher failure

rates than those >7 mm

in length

Dental implant surface

geometry is a major

determinant in how well

short dental implants

performed

Nisand & Renouard

82


12/25

To the best of our knowledge, there are only a few

descriptive studies (Table 5) that have evaluated the

impact of the crown-to-implant ratio on peri-implant

bone loss (15, 16, 97, 104, 115) , implant survival rate

(16, 104, 106) or the occurrence of biological and

technical complications (104). Among this group of

publications, three studies involved only single-tooth

implant-supported restorations (15, 104, 106), thus

avoiding the bias of better occlusal force distribution

in studies involving mainly splinted implant restora-

tions (16, 97, 115). These three studies (15, 104, 115)

demonstrated that marginal bone loss was not related

to the crown-to-implant ratio, whereas two studies

(16, 97) indicated that implant restorations with

higher crown-to-implant ratios displayed statistically

lower marginal bone loss than did implant restora-

tions with lower crown-to-implant ratios. Accordingto Blanes et al. (16), the latter might be explained by

the stimulatory nature of bone stress.

Similar survival rates have been reported for

implant restorations with high and low crown to

implant ratios (16, 104, 106). The crown-to-implant

ratio has also been found to have no statistically sig-

nicant inuence on the occurrence of biological and

technical complications (104). These results are in

accordance with the outcomes of a systematic review

performed by Blanes (17) on the impact of the crown-

to-implant ratio on the survival and complication

rates of implant-supported reconstructions. However,

it should be remembered that the crown-to-implant

ratios of most of the implant-supported restorations

included were between 1.0 and 2.0, and very few data

are available on crown-to-implant ratios of >2.0.

Therefore, further studies should investigate the

impact of crown-to-implant ratios of >2.0 on mar-

ginal bone loss, the implant survival rate and the

occurrence of biological and technical complications.

Indications and clinical procedures

Short implants

Short-length implants may be indicated without any

dogma in areas of reduced bone height (such as the

posterior maxilla and the posterior mandible) follow-

ing tooth extraction. Bone height in the premolar and

molar regions of the maxilla may be reduced by sinusexpansion. A remaining bone height of 7 mm may

indicate that short implants should be used (Fig. 6A

D). With 56 mm of available bone, the decision to

use short implants should be based on bone quality

and existing risk factors for marginal bone loss over

time (e.g. a history of periodontitis and smoking), as

well as the patients age. With


13/25

Table 5. Studies on the impact of crown-to-implant ratio

Authors (ref.

no.)

No. of

patients

(no. of

implants)

Follow-up

(months)

Type of

prosthesis

Mean crown-

to-implant

ratio

Crown-to-

implant ratio

range

Survival

rate (%)

Bone loss (mm)

Rokni et al.

2005 (97)

74 (199) 46 61.8% single

crowns

38.2% splinted

restorations

1.5 0.8 to

1 to 2:0.4 0.4

Crown-to-implant

ratio > 2: 0.3 0.5

Tawil et al.

2006 (115)

109 (262) 53 12.6% single

crowns

87.4% splinted

restorations

0.92.4 12 and > 2

83.8% with a

crown-to-

implant ratio

between 1

and 2; 3.4%

with a

crown-to-

implant ratio

of > 2

Crown-to-implant

ratio < 1: 0.88 0.74

Crown-to-

implant ratio 11.20:

0.75 0.71

Crown-to-implant

ratio 1.211.40:

0.73 0.58

Crown-to-implant

ratio 1.41

1.60: 0.77 0.71Crown-to-implant

ratio 1.612.0: 0.66

0.54

Crown-to-implant

ratio > 2: 0.74 0.65

Blanes et al.

2007 (16)

83 (192) 12 13.5% single

crowns

86.5% splinted

restorations

1.8 26.5% with a

crown-to-

implant ratio

of 2

4.2% with a

crown-to-

implant ratio

of > 3

94.1 Crown-to-implant

ratio < 1: 0.34 0.27

Crown-to-

implant ratio

1 to < 2:

0.03 0.15

Crown-to-implant

ratio 2: 0.02 0.26

Schulte et al.

2007 (106)

294 (889) 27.6 Single crowns Success

implant:

crown-to-

implant

ratio = 1.3

Failed

implant:

crown-to-

implant

ratio = 1.4

0.5 to < 3 98.2

Birdi et al.

2010 (15)

194 (309) 20.9 Single crowns 2.0 0.4 0.93.2 0.2

Schneider

et al. 2012

(104)

70 (100) 60 Single crowns Clinical

crown-to-

implant ratio:

1.50.4

Anatomical

crown-to-

implant ratio:

1.00.3

Clinical

crown-to-

implant ratio:

0.83.2

Anatomical

crown-to-

implant ratio:

0.62.0

95.8 0.008

Nisand & Renouard

84


14/25

The long-term prognosis of short-length implants

may be altered by marginal bone loss over time. Until

now, available data are too scarce to draw any deni-

tive conclusions with regard to the impact of plat-

form-switching, micro-thread and types of

connections on the peri-implant bone level of short

implants. Therefore, it is strongly recommended thatpatients should be included in supportive therapy

(96) to improve both the survival rate and the mainte-

nance of the marginal bone level. Long-term progno-

sis of short-length implants may also be affected by

peri-implantitis. However, it should be remembered

that the removal of a short implant is a relatively sim-

ple procedure with minimal bone destruction com-

pared with the removal of a long implant, which may

jeopardize adjacent teeth or the replacement of the

implant.

Implant length selection

For years, clinicians have tended to place the longest

implants possible to improve bone-to-implant con-tact, implant primary stability and the crown-to-

implant ratio. However, recent knowledge in implant

dentistry has shown that bone-to-implant contact

may also be improved by the use of micro-rough sur-

faces, and adequate implant primary stability can be

achieved through the use of an adapted surgical prep-

aration and new implant designs. Similarly, recent

publications have shown that marginal bone loss, the

implant survival rate and the incidence of complica-

tions are not related to the crown-to-implant ratio.

The placement of the longest implant possible

may have some drawbacks. It increases bone prepa-

ration time, exacerbating the risk of bone overheat-

ing and inappropriate bone preparation (oversized

bone preparation), which ultimately could reduce

implant primary stability (8). Using the longest

implant possible also increases the risk for nerve

injury or sinus perforation. Lastly, in the esthetic

Table 6. New classication for treatment of the re-sorbed maxilla

Alveolar ridge

height*

Therapeutic options

Bone type I, II,

III

Bone type IV, history

of periodontitis,

smokers, patient age


15/25

anterior area (Fig. 9AE), the use of the entire avail-

able bone may lead to overly angulated implants,

thus increasing the risk for gingival retraction and

the need for a cemented restoration. In the posterior

area, the use of the longest implant possible may be

associated with incorrect implant angulation or posi-

tion, with the occlusal consequence of inadequate

load repartition. Therefore, there are clinical situa-

tions in which the entire available bone should not

be used, to allow the surgeon to focus his limited

resources on optimal three-dimensional implant

positioning.

A

B

D

E

C

Fig. 7. (A) Preoperative cone beam computed tomography

scan of a missing right maxillary second premolar and

molars showing 13 mm of available bone below the oor

of the sinus. (B) Preoperative cone beam computed tomog-

raphy scan showing maxillary septa that may complicateSchneiderian membrane elevation. (C) The trap door is

created and the Schneiderian membrane is elevated with-

out perforation, despite the presence of an incomplete sep-

tum. (D) Postoperative cone beam computed tomography

scan 6 months after the sinus lift procedure. (E) Periapical

radiograph of the implant-supported xed partial dentureafter 4 years of loading.

Nisand & Renouard

86


16/25

A new concept in implant dentistry:the stress-minimizing surgery

In 2011, the European Association of Dental Implan-

tologists concluded its consensus conference on short

implants with the following recommendation to avoid

complications: the implant surgeon and restorative

dentist should have adequate clinical experience

(12). From this recommendation, one may legiti-

mately wonder whether this conclusion encourages

practitioners to avoid complications by focusing on

complex bone-reconstruction solutions in order to

place longer implants, or to promote alternative treat-

ments such as partial dentures or long-span dental

bridges. The statement is symptomatic of the deci-

sion-making process in implant dentistry, which

rarely considers the complexity of procedures and

instead tends to be based solely on success or survival

rates. Thus, a few percentage points higher or lower

in survival rate may be deemed sufcient to guide

therapeutic decisions. It seems that, to promote the

best overall patient outcomes, other factors, such as

feasibility and morbidity, should be considered when

making a therapeutic choice (Fig. 10AQ).

Feasibility

Experience

The actual feasibility of a large number of more com-plex surgical protocols is never touched upon in

many discussions surrounding therapeutic options. It

seems that much effort is expended to omit the reality

of clinical life for the vast majority of practitioners.

Worldwide, the average number of implants placed

annually by most practitioners is estimated to be

fewer than 50. This gure seems to be quite minimal

in terms of gaining the surgical experience required

for the implementation of complex protocols.

Studies of neurocognitive activity show that the

part of the brain that manages both complex and

novel procedures lies in the prefrontal cortex, the

most anterior region of the brain (39, 73). Tasks utiliz-

ing the prefrontal cortex require conscious effort and,

importantly, consume vast cognitive resources (105).

Complex tasks, such as surgical procedures, as well as

tasks that are unfamiliar, require the prefrontal cortex

to remain active and the brains full resources to

remain accessible. However, under some conditions,

specically stress, fatigue and burnout, this access

becomes impaired. Advanced surgeries represent par-

ticularly high-stress activities for less-experienced

Table 7. New classication for treatment of the re-sorbed mandible

Alveolar ridge height* Therapeutic options

Bone type I, II, III and IV


17/25

practitioners, and the prefrontal cortex becomes inac-

cessible in precisely the complex situations where itsuse is a priority. Over time and with repetition, com-

plex tasks become more routine and the advanced

processing abilities of the prefrontal cortex are

needed less and less to perform them. By repeatedly

practicing a single type of intervention, practitioners

described as experts have gradually transferred the

new gesture, which was initially managed by the pre-

frontal cortex, to the limbic brain. The limbic brain is

a group of brain structures consisting of multiple

subcortical entities such as the hippocampus, the

amygdala and the hypothalamus. It is located in themiddle part of the brain. This part of the brain is

involved in emotions and manages routine actions.

This automatic mental mode requires far fewer

resources and is thought to be used for as much as

80% of all activities performed.

It takes time and large amounts of repetition

before a complex act can be made partially routine

while still being accomplished with a high success

rate. Moreover, experience is necessarily obtained by

A

B D

E

C

Fig. 9. (A) Preoperative cone beam computed tomography

scan showing internal resorption of a left central incisor.

(B) Gingival retraction and inammation around the

left central incisor. (C) Six weeks after a apless tooth

extraction, the implant is placed together with a guided

bone-regeneration procedure. The implant is inserted in

the correct three-dimensional position to allow insertion

of a screw-retained prosthesis and to avoid gingival

retraction. (D) Periapical radiograph 6 months after the

placement of a provisional crown. A shorter implant

(11.5 mm in length and 3.5 mm in diameter) was used to

allow the placement of a screw-retained prosthesis. (E)

Soft tissue healing around the provisional crown after

6 months.

Nisand & Renouard

88


18/25

the occurrence of errors and failures, which are then

analyzed, primarily unconsciously, by the anterior

cingulate cortex (22), allowing the brain gradually to

adjust and routinize the procedure. This phenome-

non is made possible as a result of brain plasticity,

allowing the brain to restructure itself continuously

upon exposure to new stimuli (29). Learning leads to

a cerebral reprogramming that is based on successes

but mainly on failures. This long learning process isnecessary to transfer portions of the work of the pre-

frontal cortex to the limbic brain. The aim is that the

majority of gestures are accomplished without hav-

ing to think about them. This can occur for an

entire, or for only part of, a procedure. Uncon-

sciously, the operator uses both parts of the brain

simultaneously. The act of transferring some of the

workload to the limbic brain allows an individual

both to conserve limited mental resources (93) and

to make room in the prefrontal brain to handle new

parameters from sensory input in complex situa-

tions, such as the observations that this dissection is

difcult, the patient is becoming stressed, the

patient is bleeding more than usual or the patient

has a voluminous tongue that is interfering with sur-

gery. These additional parameters add to the com-

plexity of the situation, placing new demands on the

prefrontal cortex.

The novice practitioner who performs this type of

surgery only a few times a year will not have enough

experience to routinize the procedure. Therefore,

every act will require signicant cognitive effort, with

the risk of quickly overloading the prefrontal brain.The immediate consequence of this is to induce

stress, with the corollary being a signicant decline in

operating efciency, which, in turn, further increases

the stress level. A vicious cycle is created, eventually

leading to an uncontrolled intervention that is more

likely to generate complications.

Whatever the scope is, expertise is created over a

long learning period, estimated at about 10 years.

The more a protocol is simplied and perfectly codi-

ed, the easier it is for large numbers of people to

learn. The use of short implants ts perfectly into this

cognitive analysis of surgical difculty. While the idealwould be to rebuild all patients ad integrum,we must

accept that in reality relatively few surgeons can

acquire the necessary level of experience and exper-

tise required to perform this type of intervention with

a high and consistent success rate.

Nontechnical human factors

Many nontechnical parameters, such as stress, fati-

gue, overcondence (14) and the lack of preparation

or organization (81), can inuence the outcome of a

procedure. In this vein, a study of 9,830 surgical pro-

cedures in a London hospital demonstrates the

importance of nontechnical factors in the occurrence

of surgical complications (45). Stress is probably one

of the complicating factors shared most widely by

dental and maxillofacial surgeons. It is difcult for

most practitioners to manage both the technical and

emotional aspects of a patient who is usually underlocal anesthesia. The emotional impact of the rela-

tionship with the patient is a layer of complexity on

top of the purely technical aspect of the procedure,

making the whole treatment even more complex and

demanding even more in terms of cognitive

resources. Nevertheless, the stress and commensu-

rate increased risk of complication generated by

implementing complex procedures is rarely men-

tioned in discussions about treatment decision-mak-

ing. Stress occurs when there is a mismatch between

an individuals perception of the constraints imposed

by the environment and that individuals perception

of his or her own resources to cope with it (10, 11, 85).

We may also explain stress as a conict of resource

mobilization and accessibility: when knowledge exists

but it is not immediately available when needed,

stress occurs. We now understand that it is not the

situation that is stressful per se, but the individuals

reaction to the situation. Stress in humans is 90%

endogenous. Accordingly, a surgeon with less experi-

ence and little practice will be more stressed and will

tend to approach complex surgeries in a more nega-

tive cognitive state. Hence, the level of alertness ofthe less-experienced practitioner is more likely to be

affected by cognitive overload during these unusual

events.

Under heavy stress, practitioners or therapeutic

team members may see their cognitive abilities

diminish until they become incapable of making

rational decisions (76, 77, 109). This state is termed

mental tunneling (27, 93). Overwhelmed by stress, the

practitioner is unable to analyze the situation and the

surroundings. The practitioner may even be subject

to regression, namely the implementation of solu-

tions learned previously and now managed by thelimbic brain, forgetting recent knowledge gains. The

overstressed practitioner will then react in one of two

ways: with anxiety; or simply with the urge to avoid

the situation. This is an instance of the ght-or-ight

response (19, 24). Physically unable to leave the oper-

ating theater, the surgeon may have the impulse to

get the surgery over with, regardless of the conse-

quences of mistakes, oversights or surgical shortcuts.

Instead of prioritizing the use of their prefrontal


89


19/25

A B

D E F G

H J

K

L

N O P Q

I

M

C

Nisand & Renouard

90


20/25

brains, required to solve new and complex problems,

people under stress tend to favor the lower oors of

the brain, thus reducing their capacity for rational

analysis. The number of errors then increases with a

greater risk of complications.

An alternative response is referred to as vigilance.

This is where one uses the surge of adrenaline in a

demanding situation to heighten awareness and

decision-making skills, the obverse of the typical

ght-or-

ight

response. It is a state that requiresself-condence, which is generally a function of time

and repetition. Experience, allowing one to acquire

condence, is thus one way to reduce stress. Again,

this leads to the conclusion that complex procedures

are best performed by practitioners who have trained

over time and then practiced sufciently to maintain

their level of expertise.

The use of short implants ts perfectly into this

consideration of human factors in general and stress

in particular. Rather than attempting, in vain, solu-

tions that are best reserved, in the nal analysis, to a

few highly experienced practitioners and therefore torelatively few patients, it seems preferable to focus on

surgical techniques that do not impose the same

stress loads, such as the use of short implants. By

remaining far from anatomic obstacles and imple-

menting well-described and easily reproducible pro-

tocols, the practitioner can focus on the principal

goal of the operation, which is the correct three-

dimensional placement of the implants. The learning

curve, which is unavoidable, will nevertheless be

shorter in every way than that inherent to pre-

implant bone grafts.

Morbidity

Morbidity, dened as the set of complications that

may accompany a surgical procedure, is rarely taken

into account during therapeutic choices. However, a

number of publications reported a direct correlation

between morbidity and procedural complexity. Thus,in a study of 102 pediatric cardiac surgeries, Barach

et al. (9) show that the longer and more complex a

surgical procedure is, the higher the risk of complica-

tions. These ndings were conrmed in 2008 by Ros-

elli et al. (101), who analyzed 1,847 cardiovascular

and thoracic surgeries. In 2005, Enislidis et al. (41)

reported an implant survival rate of 96% following 45

distraction surgeries of 37 patients. Nevertheless, the

authors also identied a 65% complication rate, of

which 21% experienced serious complications,

including three mandibular fractures (41). Although

the implant success rate in this study was satisfactory,it was obtained at the cost of substantial morbidity.

Accordingly, surgical techniques and medical proto-

cols should not be evaluated solely on the basis of

survival and/or success rates. Morbidity and danger-

ousness accompanying these protocols should also

carry appropriate weight. The dangerousness of a

technique can be characterized as the probability of

occurrence of complications multiplied by the criti-

cality of these complications.

Fig. 10. (A) Othopantomogram of a 66-year-old patient,

with moderate chronic periodontitis and missing maxillary

left premolars and molars, treated with anticoagulant

therapy. The treatment plan included nonsurgical and sur-

gical periodontal treatment before restoration with

implants. (B) Preoperative cone beam computed tomogra-

phy scan showing adequate bone volume for the replace-

ment of the rst premolar. (C) Preoperative cone beam

computed tomography scan showing 23 mm of available

bone below the oor of the sinus (for replacement of therst molar). (D) Clinical view showing one straight implant

in the rst premolar position and one angulated implant

in the rst molar position to restore a three-unitxed par-

tial denture. The use of an angulated implant avoids the

need for a sinus lift procedure. (E) Clinical view of a three-

unitxed partial denture, 8 years after loading, to replace

missing rst and second premolars and rst molars. (F)

Fracture of the right central incisor in the same patient.

(G) Soft tissue healing 6 weeks after apless tooth extrac-

tion (a removable denture was used during the healing

time) at the time of implant placement. The implant was

placed together with a guided bone regeneration tech-

nique. (H) Periapical radiograph after 5 years of loading.

(I) Postoperative cone beam computed tomography scan

after 5 years of loading. A shorter implant was inserted to

replace the maxillary central incisor in order to allow the

placement of a screw-retained prosthesis. Placement of

the longest implant possible, to use all the available bone,

would have led to a cemented restoration. (J) Clinical view

after 5 years showing the implant-supported restoration

inserted to replace the right maxillary central incisor. (K)

Periapical radiograph in the same patient showing bone

healing 3 months after extraction of the right maxillaryrst molar. Nine years after the periodontal treatment,

only two teeth were lost and only one because of the pro-

gression of periodontal disease. (L) Soft tissue healing

3 months after extraction of the right maxillaryrst molar.

(M) Preoperative cone beam computed tomography scan

showing 7 mm of bone available below the oor of the

sinus. (N) Placement of a short-length implant (7 mm in

length and 5 mm in diameter) in one-step surgery. (O)

Periapical radiograph after 3 years of loading. (P) Clinical

view of the implant-supported single crown to restore the

right maxillaryrst molar after 3 years of loading. (Q) Or-

thopantomogram 9 years after the start of treatment.


91


21/25

Using these criteria, a surgical technique that has a

satisfactory success rate with a relatively high compli-

cation frequency, but low criticality, would be accept-

able, whereas a surgical technique that has a higher

success rate with a lower frequency of complications,

but with a very high criticality (e.g. mortality risk),

should be restricted if the indication is not vital. This

concept of morbidity is illustrated particularly well by

Ferrigno et al. (49). Indeed, these authors considerplacing short implants as an act with enough risk of

failure to justify a mandibular alveolar nerve laterali-

zation in order to place long implants. Although this

technique can be effective for an expert, promoting it

to mainstream surgeons should be accompanied with

serious warnings about the level of experience

required to implement it. As above, the concept of

morbidity is intimately related to the level of exper-

tise.

The morbidity of short implants is low, and the loss

of a short implant usually has only minor conse-

quences. Sometimes it is possible to re-implant;

whereas, in other situations the use of advanced sur-

gical techniques becomes necessary. Patients must be

warned about these risks before undergoing implant

treatment.

Conclusions

Short-length implants can be successfully used to

support single and multiple xed reconstructions in

posterior atrophied jaws, even with increased crown-to-implant ratios. The use of short-length implants

allows treatment of patients who are unable to

undergo complex surgical techniques for medical,

anatomic or nancial reasons. For these patients, it

must be clearly understood that the decision is short-

implant-supportedxed reconstructions, removable-

denture or long-span reconstructions on abutment

teeth or no treatment. Moreover, the use of short-

length implants in clinical practice reduces the need

for complex surgeries, thus reducing morbidity, cost

and treatment time. However, longer follow-up times

of up to 10 years (both for case series and random-ized controlled trials) are needed. Additional studies

should also investigate the impact of crown-to-

implant ratios of >2.0 and the possibility of using

extra-short implants.

The longest implant possible should not always be

used to improve the three-dimensional positioning of

implants. The use of short implants promotes the

new concept of stress-minimizing surgery, allowing

the surgeon to focus necessarily limited cognitive

resources on the correct three-dimensional position-

ing of the implant.

References

1. Anitua E, Orive G, Aguirre JJ, Anda I. Five-year clinical

evaluation of short dental implants placed in posterior

areas: a retrospective study.J Periodontol2008:79: 4248.

2. Anitua E, Orive G. Short implants in maxillae and mandi-

bles: a retrospective study with 1 to 8 years of follow-up.

J Periodontol2010:81: 819826.

3. Annibali S, Cristalli MP, DellAquila D, Bignozzi I, La Mon-

aca G, Pilloni A. Short dental implants: a systematic

review.J Dent Res2012:91: 2532.

4. Ante I. The fundamental principles of abutments. Mich

State Dent Soc Bullet1926:8: 1423.

5. Arlin ML. Short dental implants as a treatment option:

results from an observational study in a single private

practice.Int J Oral Maxillofac Implants2006:21: 769776.

6. Bahat O. Treatment planning and placement of implants

in the posterior maxillae: report of 732 consecutive Nobel-

pharma implants. Int J Oral Maxillofac Implants1993: 8 :151161.

7. Bahat O. Branemark system implants in the posterior

maxilla: clinical study of 660 implants followed for 5 to

12 years.Int J Oral Maxillofac Implants2000:15: 646653.

8. Balleri P, Cozzolino A, Ghelli L, Momicchioli G, Varriale A.

Stability measurements of osseointegrated implants using

Osstell in partially edentulous jaws after 1 year of loading:

a pilot study.Clin Implant Dent Relat Res2002:4: 128132.

9. Barach P, Johnson JK, Ahmad A, Galvan C, Bognar A, Du-

can R, Starr JP, Bacha EA. A prospective observational

study of human factors, adverse events, and patient out-

comes in surgery pediatric cardiac disease. J Thorac Car-

diovasc Surg2008:136: 14221428.

10. Bar-Tal Y, Raviv A, Spitzer A. The need and ability toachieve cognitive structuring: individual differences that

moderate the effect of stress on information processing.

J Pers Soc Psychol1999:77: 3551.

11. Beck A. Cognitive approach to stress. In: Lehrer CP, Wool-

folk RL. Clinical guide to stress management. New York:

Guilford Press, 1984.

12. Bennett P, Berger C, Bar A, Duddeck DU, Karatzas S, Kho-

ury F, Konstantinovic V, Nickenig HJ, Ramazanoglu M,

Zoller JE. European Consensus Conference of the Euro-

pean Association of Dental Implantologists Guidelines on

short and angulated implants. Eur J Implantol 2011: 2:

1322.

13. Bernard JP, Belser U, Szmuckler S, Martinet JP, Attieh A,

Saad PJ. Interet de lutilisation dimplants ITI de faible lon-gueur dans les secteurs posterieurs: resultats dune etude

clinique a 3 ans.Medecine Buccale, Chirurgie Buccale1995:

1: 118.

14. Berner ES, Graber ML. Overcondence as a Cause of Diag-

nostic Error in Medicine.Am J Med2008:121: S2S23.

15. Birdi H, Schulte J, Kovacs A, Weed M, Chuang SK. Crown--

to-implant ratios of short-length implants. J Oral Implan-

tol2010:36: 425433.

16. Blanes RJ, Bernard JP, Blanes ZM, Belser UC. A 10-year

prospective study of ITI dental implants placed in the pos-

Nisand & Renouard

92


22/25

terior region II: Inuence of the crown-to-implant ratio

and different prosthetic treatment modalities on crestal

bone loss.Clin Oral Implants Res2007:18: 707714.

17. Blanes RJ. To what extent does the crown-implant ratio

affect the survival and complications of implant-supported

reconstructions? A systematic review Clin Oral Implants

Res2009:20(Suppl 4): 6772.

18. Bornstein MM, Chappuis V, von ArxT, Buser D. Perfor-

mance of dental implants after staged sinus oor elevation

procedures: 5-year results of a prospective study in par-

tially edentulous patients.Clin Oral Implants Res2008:19:

10341043.

19. Bracha HS, Ralston TC, Matsukawa JM, Williams AE, Bra-

cha AS. Does Fight or FlightNeed Updating?Psychoso-

matics2004:45: 448449.

20. Brocard D, Barthet P, Baysse E, Duffort JF, Eller P, Justu-

mus P, Marin P, Oscaby F, Simonet T, Benque E, Brunel G.

A multicenter report on 1022 consecutively placed ITI

implants: a 7-year longitudinal study. Int J Oral Maxillofac

Implants2000:15: 691700.

21. Buser D, Mericske-Stern R, Bernard JP, Behneke A, Be-

hneke N, Hirt HP, Belser U, Lang NP. Long-term evalua-

tion of nonsubmerged ITI implants Part 1: 8-year life table

analysis of a prospective multicenter study with 2359implants.Clin Oral Implants Res1997:8: 161172.

22. Bush G, Vogt BA, Holmes J, Dale AM, Greve D, Jenike MA,

Rosen BR. Dorsal anterior cingulate cortex: a role in

reward-based decision making. Proc Natl Acad Sci USA

2002:8: 523528.

23. Cannizzaro G, Felice P, Leone M, Viola P, Esposito M. Early

loading of implants in the atrophic posterior maxilla: lat-

eral sinus liftwith autogenous bone and Bio-Oss versus

crestal mini sinus lift and 8-mm hydroxyapatite-coated

implants A randomized controlled clinical trial. Eur J Oral

Implantol2009:2: 2538.

24. Cannon WB. Bodily changes in pain, hunger, fear, and

rage. New York: Appleton-Century-Crofts, 1929.

25. Chaushu G, Taicher S, Halamish-Shani T, Givol N. Medico-legal aspects of altered sensation following implant place-

ment in the mandible.Int J Oral Maxillofac Implants2002:

17: 413415.

26. Chiapasco M, Casentini P, Zaniboni M. Bone augmenta-

tion procedures in implant dentistry.Int J Oral Maxillofac

Implants2009:24(Suppl): 237259.

27. Cook M, Noyes J, Masakowski Y.Decision making in com-

plex environnement. Ashgate: Ed 2007, 424.

28. Corrente G, Abundo R, des Ambrois AB, Savio L, Perelli M.

Short porous implants in the posterior maxilla: a 3-year

report of a prospective study. Int J Periodontics Restorative

Dent2009:29: 2329.

29. Daoudal G, Debanne D. Long-term plasticity of intrinsic

excitability: learning rules and mechanisms. Learn Mem2003:10: 456465.

30. das Neves FD, Fones D, Bernardes SR, do Prado CJ, Neto

AJ. Short implants: an analysis of longitudinal studies.Int J

Oral Maxillofac Implants2006:21: 8693.

31. Degidi M, Piattelli A, Iezzi G, Carinci F. Immediately

loaded short implants: analysis of a case series of 133

implants.Quintessence Int2007:38: 193201.

32. Deporter D, Todescan R, Caudry S. Simplifying manage-

ment of the posterior maxilla using short, porous-surfaced

dental implants and simultaneous indirect sinus elevation.

Int J Periodontics Restorative Dent2000:20: 476485.

33. Deporter D, Pilliar RM, Todescan R, Watson P, Pharoah M.

Managing the posterior mandible of partially edentulous

patients with short, porous-surfaced dental implants: early

data from a clinical trial. Int J Oral Maxillofac Implants

2001:16: 653658.

34. Deporter D, Watson P, Pharoah M, Todescan R, Tomlinson

G. Ten-year results of a prospective study using

porous-surfaced dental implants and a mandibular over-

denture.Clin Implant Dent Relat Res2002:4: 183

189.

35. Deporter DA, Caudry S, Kermalli J, Adegbembo A. Further

data on the predictability of the indirect sinus elevation

procedure used with short, sintered, porous-surfaced den-

tal implants. Int J Periodontics Restorative Dent2005: 25:

585593.

36. Deporter D, Ogiso B, Sohn DS, Ruljancich K, Pharoah M.

Ultrashort sintered porous-surfaced dental implants used

to replace posterior teeth. J Periodontol 2008: 79: 1280

1286.

37. De Santis D, Cucchi A, Longhi C, Vincenzo B. Short

threaded implants with an oxidized surface to restore pos-

terior teeth: 1- to 3-year results of a prospective study.Int J

Oral Maxillofac Implants2011:26: 393

403.38. Draenert FG, Sagheb K, Baumgardt K, Kammerer PW. Ret-

rospective analysis of survival rates and marginal bone loss

on short implants in the mandible. Clin Oral Implants Res

2012:23: 10631069.

39. Ducan J, Seitz RJ, Kolodny J, Bor D, Herzog H, Ahmed A,

Newell F, Emslie H. A neural basis of general intelligence.

Science2000:289: 457460.

40. Ellegaard B, Baelum V, Karring T. Implant therapy in peri-

odontally compromised patients. Clin Oral Implants Res

1997:8: 180188.

41. Enislidis G, Fock N, Millesi-Schobel G, Klug C, Wittwer G,

Yerit K, Ewers R. Analysis of complications following alveo-

lar distraction osteogenesis and implant placement in the

partially edentulous mandible. Oral Surg Oral Med OralPathol Oral Radio Endod2005:100: 2530.

42. Esposito M, Grusovin MG, Felice P, Karatzopoulos G, Wor-

thington HV, Coulthard P. The efcacy of horizontal and

vertical bone augmentation procedures for dental

implants a Cochrane systematic review. Eur J Oral Im-

plantol2009:2: 167184.

43. Esposito M, Pellegrino G, Pistilli R, Felice P. Rehabilitation

of posterior atrophic edentulous jaws: prostheses sup-

ported by 5 mm short implants or by longer implants in

augmented bone? One-year results from a pilot rando-

mised clinical trialEur J Oral Implantol2011:4: 2130.

44. Esposito M, Cannizarro G, Soardi E, Pellegrino G, Pistilli R,

Felice P. A 3-year post-loading report of a randomised

controlled trial on the rehabilitation of posterior atrophicmandibles: short implants or longer implants in vertically

augmented bone?Eur J Oral Implantol2011:4: 301311.

45. Fabri PJ, Zayas-Castro JL. Human error, not communica-

tion and systems, underlies surgical complications.Surgery

2008:144: 557563.

46. Feldman S, Boitel N, Weng D, Kohles SS, Stach RM. Five--

year survival distributions of short length (10 mm or less)

machined surfaced and Osseotite implants. Clin Implant

Dent Relat Res2004:6: 1623.


93


23/25

47. Felice P, Pellegrino G, Checchi L, Pistilli R, Esposito M.

Vertical augmentation with interpositional blocks of anor-

ganic bovine bone vs. 7-mm-long implants in posterior

mandibles: 1-year results of a randomized clinical trial.

Clin Oral Implants Res2010:21: 13941403.

48. Felice P, Soardi E, Pellegrino G, Pistilli R, Marchetti C, Ges-

saroli M, Esposito M. Treatment of the atrophic edentu-

lous maxilla: short implants versus bone augmentation for

placing longer implants Five-month post-loading results

of a pilot randomised controlled trial.Eur J Oral Implantol

2011:4: 191

202.

49. Ferrigno N, Laureti M, Fanali S. Inferior alveolar nerve

transposition in conjunction with implant placement. Int J


50. Ferrigno N, Laureti M, Fanali S. Dental implants place-

ment in conjunction with osteotome sinus oor elevation:

a 12-year life-table analysis from a prospective study

on 588 ITI implants. Clin Oral Implants Res 2006: 17:

194205.

51. Friberg B, Jemt T, Lekholm U. Early failure in 4641 consec-

utively placed Branemark dental implants: a study from

stage 1 to the connection of completed prostheses. Int J


52. Friberg B, Gr

ondahl K, Lekholm U, Br

anemark PI. Long--term follow-up of severely atrophic edentulous mandibles

reconstructed with short Branemark implants. Clin

Implant Dent Relat Res2000:2: 184189.

53. Friberg B. The posterior maxilla: clinical considerations

and current concepts using Branemark System implants.

Periodontol 20002008:47: 6778.

54. Fugazzotto PA, Beagle JR, Ganeles J, Jafn R, Vlassis J, Ku-

mar A. Success and failure rates of 9 mm or shorter

implants in the replacement of missing maxillary molars

when restored with individual crowns: preliminary results

0 to 84 months in function A retrospective study. J Period-

ontol2004:75: 327332.

55. Fugazzotto PA. Shorter implants in clinical practice: ratio-

nale and treatment results. Int J Oral Maxillofac Implants2008:23: 487496.

56. Goene R, Bianchesi C, Huerzeler M, Del Lupo R, Testori T,

Davarpanah M, Jalbout Z. Performance of short implants

in partial restorations: 3-year follow-up of Osseotite

implants.Implant Dent2005:14: 274280.

57. Grant BT, Pancko FX, Kraut RA. Outcomes of placing short

dental implants in the posterior mandible: a retrospective

study of 124 cases.J Oral Maxillofac Surg2009: 67: 713717.

58. Grifn TJ, Cheung WS. The use of short, wide implants in

posterior areas with reduced bone height: a retrospective

investigation.J Prosthet Dent2004:92: 139144.

59. Grimes DA, Schulz KF. An overview of clinical research:

the lay of the land.Lancet2002:5: 5761.

60. Gulje F, Raghoebar GM, Ter Meulen JW, Vissink A, MeijerHJ. Mandibular overdentures supported by 6-mm dental

implants: a 1-year prospective cohort study. Clin Implant

Dent Relat Res2012:14(Suppl 1): e5966.

61. Gunne J, Astrand P, Lindh T, Borg K, Olsson M. Tooth-im-

plant and implant supported xed partial dentures: a

10-year report.Int J Prosthodontics1999:12: 216221.

62. Hagi D, Deporter DA, Pilliar RM, Arenovich T. A targeted

review of study outcomes with short (


24/25

79. Misch CE. Short dental implants: a literature review and

rationale for use.Dent Today2005:24: 6466.

80. Misch CE, Steignga J, Barboza E, Misch-Dietsh F, Cianciola

LJ, Kazor C. Short dental implants in posterior partial

edentulism: a multicenter retrospective 6-year case series

study.J Periodontol2006:77: 13401347.

81. Morris JA Jr, Carrillo Y, Jenkins JM, Smith PW, Bledsoe S,

Pichert J, White A. Surgical adverse events, risk manage-

ment, and malpractice outcome: morbidity and mortality

review is not enough.Ann Surg2003:237: 844851.

82. Naert I, Koutsikakis G, Duyck J, Quirynen M, Jacobs R, van

Steenberghe D. Biologic outcome of implant-supported

restorations in the treatment of partial edentulism Part I: a

longitudinal clinical evaluation. Clin Oral Implants Res

2002:13: 381389.

83. Nedir R, Bischof M, Briaux JM, Beyer S, Szmukler-Moncler

S, Bernard JP. A 7-year life table analysis from a prospec-

tive study on ITI implants with special emphasis on the

use of short implants Results from a private practice. Clin

Oral Implants Res2004:15: 150157.

84. Neldam CA, Pinholt EM. State of the art of short dental

implants: a systematic review of the literature. Clin

Implant Dent Relat Res2012:14: 622632.

85. Neuberg S, Newsom J. Personal need for structure: individ-ual differences in chronic motivation to simplify.J Pers Soc

Psychol1993:65: 113131.

86. Perelli M, Abundo R, Corrente G, Saccone C. Short (5 and

7 mm long) porous implant in the posterior atrophic man-

dible: a 5-year report of a prospective study.Eur J Oral Im-

plantol2011:4: 363368.

87. Pjetursson BE, Tan WC, Zwahlen M, Lang NP. A system-

atic review of the success of sinus oor elevation and

survival of implants inserted in combination with sinus

oor elevation. J Clin Periodontol 2008: 35(Suppl.8): 216

240.

88. Polo WC, de Araujo NS, Lima YB, Joly JC, Sendyk WR, Cury

PR. Peri-implant bone loss around posterior mandible

dental implants placed after distraction osteogenesis: pre-liminaryndings.J Periodontol2007:78: 204208.

89. Pommer B, Frantal S, Willer J, Posch M, Watzek G, Tepper

G. Impact of dental implant length on early failure rates: a

meta-analysis of observational studies. J Clin Periodontol

2011:38: 856863.

90. Raviv E, Turcotte A, Harel-Raviv M. Short dental implants

in reduced alveolar bone height.Quintessence Int2010:41:

575579.

91. Renouard F, Nisand D. Short implants in the severely re-

sorbed maxilla: a 2-year retrospective clinical study. Clin

Implant Dent Relat Res2005:7(Suppl 1): S104S110.

92. Renouard F, Nisand D. Impact of implant length and

diameter on survival rates. Clin Oral Implants Res2006:17

(Suppl 2): 35

51.93. Renouard F, Charrier JG. In: The search for the weakest

link. An introduction to human factors. Paris: Ewenn Ed,

2012.

94. Rocchietta I, Fontana F, Simion M. Clinical outcomes of

vertical bone augmentation to enable dental implant

placement: a systematic review.J Clin Periodontol2008:35

(Suppl. 8): 203215.

95. Rocchietta I, Nisand D. A review assessing the quality of

reporting of risk factor research in implant dentistry using

smoking, diabetes and periodontitis and implant loss as

an outcome: critical aspects in design and outcome

assessment. J Clin Periodontol 2012: 39(Suppl. 12):

114121.

96. Roccuzzo M, De Angelis N, Bonino L, Aglietta M. Ten-year

results of a three-arm prospective cohort study on

implants in periodontally compromised patients Part 1:

implant loss and radiographic bone loss. Clin Oral

Implants Res2010:21: 490496.

97. Rokni S, Todescan R, Watson P, Pharoah M, Adegbembo

AO, Deporter D. An assessment of crown-to-root ratios

with short sintered porous-surfaced implants supporting

prostheses in partially edentulous patients. Int J Oral Max-

illofac Implants2005:20: 6976.

98. Romeo E, Lops D, Margutti E, Ghisol M, Chiapasco M,

Vogel G. Long-term survival and success of oral implants

in the treatment of full and partial arches: a 7-year pro-

spective study with the ITI dental implant system. Int J


99. Romeo E, GhisolM, Rozza R, Chiapasco M, Lops D. Short

(8-mm) dental implants in the rehabilitation of partial and

complete edentulism: a 3- to 14-year longitudinal study.

Int J Prosthodont2006:19: 586592.

100. Romeo E, Bivio A, Mosca D, Scanferla M, GhisolM, Stor-

elli S. The use of short dental implants in clinical practice:literature review.Minerva Stomatol2010:59: 2331.

101. Roselli EE, Pettersson GB, Blackstone EH, Brizzio ME,

Houghtaling PL, Hauck R, Burke JM, Lytle BW. Adverse

events during reoperative cardiac surgery: frequency,

characterization, and rescue. J Thorac Cardiovasc Surg

2008:135: 316323.

102. Rossi F, Ricci E, Marchetti C, Lang NP, Botticelli D. Early

loading of single crowns supported by 6-mm-long

implants with a moderately rough surface: a prospective

2-year follow-up cohort study. Clin Oral Implants Res

2010:21: 937943.

103. Sanchez-Garces MA, Costa-Berenguer X, Gay-Escoda C.

Short implants: a descriptive study of 273 implants. Clin

Implant Dent Relat Res2012:14: 508

516.104. Schneider D, Witt L, Hammerle CH. Inuence of the

crown-to-implant length ratio on the clinical performance

of implants supporting single crown restorations: a

cross-sectional retrospective 5-year investigation. Clin

Oral Implants Res2012:23: 169174.

105. Schoenbaum G, Roesch M. Orbitofrontal cortex, associa-

tive learning, and expectancies.Neuron2005:47: 633636.

106. Schulte J, Flores AM, Weed M. Crown-to-implant ratios of

single tooth implant-supported restorations. J Prosthet

Dent2007:98: 15.

107. Simion M, Jovanovic SA, Tinti C, Benfenati SP. Long-term

evaluation of osseointegrated implants inserted at the

time or after vertical ridge augmentation. A retrospective

study on 123 implants with 1-5 year follow-up. Clin OralImplants Res2001:12: 3545.

108. Slotte C, Grnningsaeter A, Halmy AM, Ohrnell LO, Stroh

G, Isaksson S, Johansson LA, Mordenfeld A, Eklund J,

Embring J. Four-millimeter implants supporting xed

partial dental prostheses in the severely resorbed posterior

mandible: two-year results. Clin Implant Dent Relat Res

2012:14(Suppl 1): e46e58.

109. Starcke K, Brand M. Decision making under stress: a

selective review. Neurosci Biobehav Rev 2012: 36:

12281248.


95


25/25

110. Stellingsma C, Meijer HJ, Raghoebar GM. Use of short

endosseous implants and an overdenture in the extremely

resorbed mandible: ave-year retrospective study. J Oral

Maxillofac Surg2000:58: 382387.

111. Stellingsma K, Bouma J, Stegenga B, Meijer HJA, Raghoe-

bar GM. Satisfaction and psychosocial aspects of patients

with an extremely resorbed mandible treated with

implant-retained overdentures. Clin Oral Implants Res

2003:14: 166172.

112. Strietzel FP, Reichart PA. Oral rehabilitation using Camlog

screw-cylinder implants with a particle-blasted and acid-

etched microstructured surface Results from a prospective

study with special consideration of short implants. Clinical

evaluation of short, machined-surface implants followed

for 12 to 92 months. Clin Oral Implants Res 2007: 18:

591600.

113. Sun HL, Huang C, Wu YR, Shi B. Failure rates of short (

10 mm) dental implants and factors inuencing their fail-

ure: a systematic review. Int J Oral Maxillofac Implants

2011:26: 816825.

114. Tawil G, Younan R. Clinical evaluation of short,

machined-surface implants followed for 12 to 92 months.

Int J Oral Maxillofac Implants2003:18: 894901.

115. Tawil G, Aboujaoude N, Younan R. In

uence of prostheticparameters on the survival and complication rates of

short implants. Int J Oral Maxillofac Implants 2006: 21:

275282.

116. Telleman G, Raghoebar GM, Vissink A, den Hartog L, Hud-

dleston Slater JJ, Meijer HJ. A systematic review of the

prognosis of short (

Short implant in limited bone volume.pdf

Documents

Transcript of Short implant in limited bone volume.pdf