Determining Osseous Resection During SurgicalCrown Lengthening in the Esthetic Zone with theUse of a Radiographic and Surgical Template

Luca Landi, DDS, CAGS*Paolo F. Manicone, DDS**Stefano Piccinelli, DDS***Roberto Raia, DDS***Fabio Marinotti, CDT**** Fabio Scutellà, DDS, MS*****

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urgical crown lengthening is defined asa procedure used to expose soundtooth structure with or without removal

of alveolar bone for restorative purposes.1 When-ever the crown extension includes removal ofsupporting bone, the principles of osseous resec-tive surgery should be applied. The objectives ofosseous resective surgery include (1) eliminationof alveolar bone alterations due to periodontaldisease activity2; (2) establishment of a physio-

logic supracrestal gingival tissue (SGT) in cases ofviolation of the biologic width3; and (3) correctionof unesthetic soft and hard tissue aberrations.4

While alveolar bone deformities resulting fromperiodontal disease dictate the degree of osteo-plasty and ostectomy needed to achieve a posi-tive architecture,4 the same cannot be applied tosurgical crown-lengthening procedures. In such in-stances, alveolar bone anatomy retains its physio-logic contour and the periodontist relies only onthe proposed restoration finish line to determineadequate ostectomy to achieve a physiologicSGT. Recently, Scutellà et al5 introduced the use ofa surgical template to guide the bone resection.Their device was primarily indicated in those caseswhere the amount of residual crown did not allowfabrication of a retentive provisional restoration,such as with severe tooth breakdown as a result ofcaries or extensive tooth abrasion subsequent tobruxism or bulimic disorders.

Because of the invasive and irreversible natureof surgical crown lengthening, several factors

*Private practice, Studio di Odontoiatria Ricostruttiva,Rome, Italy; University of Modena & Reggio Emilia (Italy).

**Private practice, Studio di Odontoiatria Ricostruttiva,Rome, Italy; Catholic University of Sacred Heart, Rome,Italy.

***Private practice, Studio di Odontoiatria Ricostruttiva,Rome, Italy.

****Dental laboratory technician, Rome, Italy.*****Private practice, Rome, Italy.Correspondence to: Dr Luca Landi, Studio di OdontoiatriaRicostruttiva, Via della Balduina 114, 00136 Rome, Italy. Fax:39-06-35403508. E-mail: studio.ric@tin.it.

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should be considered before osseous resectivesurgery is performed: crown-to-root ratio, amountof keratinized gingiva, root alterations or furcationdefects, esthetic concerns of both the patient andthe clinician, and altered passive eruption. The ex-pected residual periodontal attachment after sur-gical bone recontouring seems to be the mostcritical factor for long-term tooth stability. In someinstances, the roots are extremely short, eithercongenitally or as a consequence of resorption re-sulting from previous orthodontic therapy. There-fore, the feasibility of the proposed surgical pro-cedure should be evaluated well in advance andweighed against other available treatment alter-natives.

Bragger et al6 showed that surgical crownlengthening might be less predictable than theprofession currently anticipates. One possible ex-planation may be the lack of guidance providedduring bone resection resulting either in excessiveor inadequate bone resection. Carnevale andPontoriero7 recently pointed out that even inthose cases where the principles of osseous resec-tive surgery have been correctly applied, theamount of crown extension after 1 year of healingmight have been less than adequate. They at-tributed this phenomenon to “soft tissue re-bound.” On the other hand, the bone removalmay exceed the amount actually needed. In thesecases, the achievement of a physiologic SGT mayhave been obtained by an excessive reduction ofthe attachment apparatus, [Au: has editing re-tained your meaning?] thus jeopardizing thelong-term stability of the tooth.

In esthetic areas, surgical treatment cannot befocused only on the achievement of an adequateSGT or a more retentive restoration preparation.Conversely, the surgical plan should account forall of the variables that may play a role in the finaloutcome. In this article, the authors present atechnique that may help to guide the periodontaland restorative team to formulate an accurate di-agnosis and therefore more precisely predict thefeasibility of surgical crown lengthening in the es-thetic zone.

CASE PRESENTATION

Diagnostic Procedure and Template Fabrication

A 32-year-old female patient presented in our cliniccomplaining about the poor esthetics of an existingfixed partial denture in the maxillary anterior region(Fig 1). The existing prosthesis had been deliveredmore than 2 years previously, and since that timethe patient had experienced recurrent gingival in-flammation. Porcelain had chipped soon after pros-thesis insertion and was never repaired (Fig 2).

A complete intraoral examination including full-mouth radiographs, periodontal probing, studycasts mounted on an articulator with a facebowregistration and intraoral and extraoral pho-tographs was accomplished. Based on the clinicaland radiographic data, the patient was diagnosedas having an altered passive eruption (type II A,according to Coslet et al8) in the maxillary arch, aviolation of the SGT resulting from faulty restora-tions, uneven gingival margin architecture (Fig 3),and a lesion of endodontic origin on the right lat-eral incisor and canine (Fig 4).

Analysis of the smile line revealed a moderatedisplay of gingival tissues (Fig 5). A diagnostic softtissue contour cast was developed, and a tem-plate was fabricated. The goals of the proposedtherapy were to re-establish a physiologic SGT, in-crease the clinical crown length, correct the al-tered passive eruption, and improve the gingivaldisplay and the gingival margin architecture.

Following endodontic treatment and recon-struction of all maxillary anterior foundationrestorations, a first set of provisional restorationswas delivered (Figs 6 and 7). At this point, an idealproposed contour cast of the anterior sextant wasagain developed to determine the correct propor-tion of the clinical crowns to the gingival architec-ture and smile line (Figs 8 and 9).

A clear acrylic resin template duplicating the di-agnostic contours was then fabricated. Once thedevice was made, a 0.2-mm-diameter orthodonticwire was adapted and bonded at the cervical mar-gin of the teeth (Figs 10a to 10c). The template

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was tried in and relined on the posterior teeth withautopolymerizing acrylic resin to ensure adequatestability during the planned periodontal surgery(Figs 11a to 11d). The template was fabricated insuch a way that the cervical margin would com-press the gingiva to minimize the discrepancy be-tween the position of the template and the bonecrest. This was done to overcome one of the majordrawbacks the authors had previously experiencedwith the templates5: that is, because of the hori-zontal discrepancy between the soft and hard tis-sue, it was difficult to complete the bone reshap-ing according to the contour of the template.

Standard periapical radiographs using an XCPRinn device (Dentsply Rinn, Elgin, IL) were alsomade (Fig 12); this facilitates identification of theposition of the cervical margin on the buccal sur-face of the teeth in the proposed surgical site.With this information, the surgeon can ideallymove the bone crest in an apical direction toachieve an adequate SGT. As a consequence, theresidual gingival attachment position can be antic-ipated more consistently. Once the diagnosis wasconfirmed, the surgical procedure was plannedand performed.

Fig 4 Periapical radiographs reveala lesion of endodontic origin, as wellas recurrent decay, on the right lat-eral incisor and canine. All the crownmargins display discrepancies.Residual enamel is apparent on theright central incisor and both lateralincisors. The interdental crestal bonetissues approximate the cementoe-namel junction (CEJ) in all of the in-terproximal spaces, suggesting analtered passive eruption.

Fig 1 Frontal view of the patient’smaxillary anterior sextant at the ini-tial consultation. Poor esthetics areclearly visible. The marginal peri-odontal tissues are erythematousand edematous and display loss ofphysiologic architecture.

Fig 2 The porcelain on the lingualsurfaces is chipped.

Fig 3 The previous restorationshave been removed. The cervicalmargins of both lateral incisors aremore apical than those of the otherteeth, creating an obvious discrep-ancy of the gingival margin.

Initial Presentation

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Fig 6 Following endodontic treatment and abutmentreconstruction, an initial, under-reduced preparation ofthe teeth is performed to accommodate the provisionalrestorations. The quality of the soft tissue margin showsa marked improvement.

Fig 7 A set of provisional restorations is fabricated anddelivered to improve the esthetics and create a morehealthy environment for the soft tissue interface.

Fig 8 The location of the apex of the parabola at thefuture crown and soft tissue margin is marked with a redpencil. The most apical gingival margin is used as thelandmark, and from that point, a proposed ideal con-tour of the other margins is outlined.

Fig 9 A diagnostic soft tissue contours cast is then de-veloped based on the indicated new crown length. Be-cause the gingival margin of the right lateral incisor islocated more apically than that of the other incisors, arather flat architecture may result at the end of treat-ment in this region.

Fig 5 The patient’s smile reveals an uneven gingival ar-chitecture concurrent with unacceptable prosthodonticrestorations. Mismatched shade and inadequate toothcontours are the dominant features of the smile. A cer-tain degree of excessive gingival display is also evident.Considering the presence of an altered passive eruptionand looking at the location of the gingival margin in theposterior sextants, it is possible to visualize the physio-logic appearance of the anatomic crowns.

Diagnosis and First Provisional Restoration

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Figs 10a to 10c Stainless steel wire is adapted to the cervical margin of the template. The wire is then bonded tothe acrylic.

Figs 11a to 11d The template is tried in to evaluate the fit and adaptation. The cervical margin of the template ispositioned as close as possible to the gingiva to reduce the horizontal discrepancy between the template and thealveolar crest once the flap is reflected.

Template Fabrication

11a 11b

11c 11d

Fig 12 Standard periapical radio-graphs show the relationships be-tween the template and theanatomic landmarks, including theinterproximal osseous crest, the CEJ,the restoration margin, and the rootlength. Because of radiographic pro-jection, only one tooth is evaluatedin each radiograph.

Surgical Procedure

The surgical site was infiltrated with local anaes-thetic supplemented with epinephrine 1:100,000to ensure sufficient hemostasis. The tissue wasthin and scalloped, and the defective restorationsfurther altered the physiologic architecture. Par-ticularly, the gingival margin of the maxillary rightlateral incisor was more apical to that of the otheranterior teeth. An adequate band of keratinized

gingiva was clinically present. With these factorsin mind, the template was positioned, and a full-thickness submarginal beveled incision was madelabially outlining the margin of the surgical tem-plate (Figs 13a and 13b). After the template wasremoved,[Au: ok to add this step?] the flap wasfully reflected, and the secondary flap tissue waseliminated by surgical thinning. The surgical tem-plate was reinserted and the amount of ostec-tomy reevaluated.

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Surgery

Figs 13a and 13b Surgical incisions are made according to the information provided from the template. In thiscase, the amount of keratinized gingiva allows a submarginal, beveled, full-thickness incision.

Fig 14a The alveolar bone crest immediately after flap reflection and degranulation. The palatal flap has not beenelevated, and the residual enamel confirms an altered passive eruption.

Fig 14b The ostectomy procedure is performed using the surgical template as a guide to create the desired scal-loped architecture. Because of the very thin buccal bone plate, minimal osteoplasty is performed. The periodontalprobe indicates the distance achieved between the highest convexity of the buccal soft tissue parabola and theCEJ, about 4.5 mm. This dimension could not be achieved without the use of a surgical template.

Fig 14c The anterior sextant after osseous surgery.

14a 14b 14c

Because of the thin buccal bone, minimal os-teoplasty was accomplished. Hand chisel instru-ments (Ochsenbein Nos. 1 and 2, Hu-Friedy,Chicago, IL) were used for the bone resection pro-cedure. At each step of the resection, the tem-plate was repositioned and the amount of ostec-tomy rechecked until the desired crown extensionwas achieved (Figs 14a to 14c). The buccal flapwas placed into proper position to achieve pas-sive closure, and vertical mattress sutures, using 4-0 silk suture material, were made to insure soft tis-

sue adaptation. The surgical guide was onceagain used to verify that the flap position was con-sistent with the margin of the surgical template(Figs 15a to 15c).

The patient was instructed to refrain frombrushing, and a 0.2% chlorhexidine mouthwashwas prescribed for use twice a day until mechani-cal tooth cleaning was resumed. A nonsteroidalanti-inflammatory drug was administered immedi-ately after surgery and then again every 12 hoursfor 48 hours.

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Figs 15a to 15c The flap is suturedinto position with 4-0 silk continuousvertical mattress sutures. The tem-plate is again positioned to verifyflap adaptation.

15b 15c

15a

Healing

Sutures were removed after 7 days, and the heal-ing was uneventful. Follow-up appointments oc-curred weekly until adequate patient hygiene wasdemonstrated. At each appointment, the tem-plate was reinserted to monitor the tissue posi-

tion and maturation as healing progressed (Figs16a and 16b).

Twelve weeks after the surgical procedure, theteeth were prepared and the provisional restora-tions were relined. Care was taken to prepare theteeth 0.5 to 1.0 mm coronal to the soft tissue mar-gins to avoid any violation of the SGT in order to

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Figs 16a and 16b Clinical view 6weeks postsurgery. The tissue matu-ration is monitored using the tem-plate as a reference. Since the posi-tion of the flap in relationship to thebone crest was determined just aftersurgery, [Au: is this what youmeant?] it is easy to evaluate thedevelopment of the SGT.

Tissue Healing and Second Provisional Restorations

Fig 17 Twelve weeks postsurgery, the tissue is still ma-turing. The teeth are more definitively prepared, 0.5 to1.0 mm away from the gingival margin to protect thedevelopment of the SGT. The provisional restorationsare again relined.

Fig 18 Occlusal view of the provisional restorations onthe master cast. Six months postsurgery a new set ofprovisional restorations is delivered. A polyvinyl siloxaneimpression is made, and the provisional contours aremodified to create an appropriate emergence profile tofurther guide the soft tissue maturation.

16a

16b

facilitate tissue maturation (Fig 17). Three monthsafter surgery, tissue maturation was again evalu-ated using the surgical template as a guide, and apolyvinyl siloxane impression was made for a sec-ond set of provisional restorations (Figs 18 and 19).

Nine months after surgery, findings at the recallappointment revealed that a physiologic SGT was

fully developed, and final prosthodontic therapyproceeded as planned (Figs 20a to 20c). AuroGalva Crown (Wielan, Pforzheim, Germany)restorations were fabricated and delivered shortlythereafter (Figs 21 to 24).

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Figs 19a and 19b The provisional crowns are seated onthe abutments. Shape, length (frontal view), and incisaledge position (lateral view) are greatly improved overthe presurgical contours. The emergence profile wascustomized to allow physiologic tissue development.

Figs 20a to 20c Soft issue matura-tion is evident prior to making thefinal impression. The interdentalpapilla between the central incisors isfully developed, while those at thelateral incisors have a lower profile.The lateral views also show the physi-ologic position of the prosthodonticmargins within the gingival sulcus.The tissue is stable and adequatelysupported by the provisional restora-tion’s emergence profile.

19b

19a

20a

20b

20c

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Tissue Healing and Second Provisional Restorations (continued)

Fig 21 Occlusal view of the pre-pared teeth prior to try-in of thedefinitive restorations. [Au: Pleaseexplain the gold coating on theteeth.]

Fig 22 Crown shape and form of the definitive restorations closely resem-ble those of the second set of provisional restorations (see Fig 19a), withthe parabolas of the central and lateral incisors lying almost on the samelevel. Nevertheless, the alignment of the free gingival margins and the re-sultant symmetry create an esthetically pleasing architecture.

Figs 23a and 23b The incisal length of the definitivecrowns has been lengthened approximately 1 mm. Thetexture of the ceramic surface can be better evaluatedwith the use of black and white photography.

Fig 24 Radiographic evaluation 3 months postcemen-tation. The marginal fit of the restorations to the teeth,the physiologic bone crest position, and the anatomyare acceptable. Healing of the periapical lesion is alsoremarkable.

23a

24

23b

DISCUSSION

Surgical crown-lengthening procedures are gen-erally performed using the parameters first intro-duced by Gargiulo et al9 in 1961. These concepts,based on autopsies of 30 dry human skulls andadditional histologic findings, defined averagemeasurements for sulcus depth (0.69 mm), junc-tional epithelial attachment (0.97 mm), and con-nective tissue attachment from the CEJ to thealveolar bone crest (1.07 mm). The sum of the lin-ear measurements for junctional epithelium andconnective tissue (2.04 mm) was later termed byCohen10 as biologic width.

Since its introduction, the biologic width hasbeen widely discussed in dental journals and usedby clinicians as a reference point in periodontal-restorative procedures. However, some commentsabout the earlier studies of Gargiulo et al9 can bemade. The anatomic measurements used werethe averages between 30 different human skullsand were not representative of all individuals, allteeth, or all sites around one specific tooth. Fur-thermore, the sulcus depth (0.69 mm) was ob-tained from cadavers, while clinical depths in liv-ing bodies range from 1 to 3 mm,11 depending onprevailing inflammation, probing force used, andthe location measured on a given tooth. Withthese observations in mind, it would seem thatsulcus depth represents the greatest variance inthe old concept of biologic width, whereas theleast variance is that of the true biologic width(junctional epithelium and connective tissue at-tachment).

Some authors12–15 have challenged the mea-surements for the junctional epithelium and con-nective tissue attachment [Au: is this what youmeant?], proposing a more generous bone re-section for prosthetic purposes. However, thosestudies provided no scientific-based evidence onhow much bone tissue should be removed in thecase of surgical crown lengthening. Recently,Kois16 and Smukler and Chaibi3 have introducednew concepts of biologic width, respectivelycalled dentogingival complex and supracrestalgingival tissue, which are characterized by in-

terindividual and intraindividual variability and inwhich the sulcus depth is a predominant factor.According to these concepts, individual toothand site measurements rather than average mea-surements should be used. This may partly ex-plain why it is sometimes not possible to pre-dictably achieve adequate crown extension usingaverage measurements.6,17

Several factors other than those related to thepatient (such as SGT, tissue biotype, and plaquecontrol) also can affect treatment outcomes. Theselected surgical technique and its applicationmay be also important for the end result.7 Carefulosseous resection, in conjunction with positioningof the flap margin apical to the osseous crest (andnot a more coronal positioning), leads to an ini-tially greater crown extension. Carnevale and Pon-toriero,7 using osseous surgery and repositioningof the flap apical to the bone crest, were able toachieve crown extension 4.1 mm buccally and 3.7mm interproximally. However, after 12 months ofhealing, 2.9 mm buccal and 3.2 mm interproximaltissue regrowth was registered, leaving a finalcrown lengthening of 1.2 mm buccally and 0.5mm interproximally.

On the other hand, Bragger et al6 applied theconcept of osseous resective surgery in a differentmanner, positioning the flap over the osseouscrest. The mean crown extension resulting at theend of that surgery (1.3 mm) remained stable at 6months. This may be due to the fact that flapthickness over the crest was already accommodat-ing a physiologic SGT and therefore very little tis-sue regrowth would be expected. However, it isnoteworthy that at the completion of the healingphase, 22.5% of the cases reported had gingivalmargins located at or coronal to the preoperativesoft tissue levels. Furthermore, 30% of the teethexhibited increased gingival recession, while 33%showed growth in a coronal direction. All of theseresults indicate poor tissue stability and an unevengingival margin. [Au: words were missing here.is this what you meant?] Therefore, tissue re-growth or maturation should be expected in rela-tion to the surgical technique selected and bio-metric characteristics of the tissue.7

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It is commonly accepted that a long period oftime should pass before the restorative phase oftreatment is completed following surgery. This al-lows the tissue to stabilize and a physiologic SGTto be reestablished via a development of a clinicalsulcus. It is known that tissue regrowth occurs upto 12 months after surgery.7,18,19 The prostheticpreparation should not be placed subgingivallyduring tissue maturation, as this may violate theSGT. Three months after healing, the finishing linemay be outlined, and then the residual regrowthwill determine the most physiologic location ofthe tissue margin.

The template previously described by Scutellàet al5 was mainly indicated for cases in which pro-visional restorations could not be delivered be-cause of severe tooth wear. In the present case,provisional restorations were delivered, but sev-eral considerations led the authors to use a diag-nostic tool to plan the surgical procedure. Thesurgical goals of this case were to reestablish aphysiologic SGT, increase the clinical crownlength, correct the altered passive eruption, andimprove the gingival tissue display. It may some-times be difficult to address all of these issuesthrough surgery alone. The restorative marginscannot be considered a landmark by which toconduct the ostectomy because they do not pro-vide reliable information on where the final crownmargins will be placed according to esthetic pa-rameters. Therefore, rather than rely on the abilityof the periodontist to foresee the shape and pro-portion of the definitive restorations, the authorsbelieve that a surgical template, representing thefinal restorative goal, would increase the chancesof predictable results.

This treatment aid can also be used to monitortissue development during healing. If the presur-gical SGT and the postsurgical position of the os-seous crest are known, the degree of coronal dis-placement of the gingival margin can bedetermined more predictably at any given time.

For this case, the definitive restorations weredelivered about 9 months after surgery. This time-

frame was guided by the information gatheredfrom the template and by the fact that, for thingingiva, about 90% of the regrowth had alreadytaken place.7

CONCLUSIONS

A surgical template provides a simple and reliablemethod of relaying critical information necessaryin complex treatment strategies. It provides theperiodontal-restorative team with the ability to an-ticipate the treatment outcome and improvescommunication between the various careproviders involved. The indications for its use inthe clinical setting are broader than those previ-ously presented5 and may be divided into bothpresurgical and postsurgical uses. Presurgicallythe template is indicated when provisionalrestorations cannot be delivered (as when ex-treme tooth wear is exhibited), for situations withshort or resorbed roots, and when provisionalrestorations can be delivered (such as in estheticareas and for cases of excessive display of gingivaltissues, violation of SGT, altered passive eruption,and uneven gingival architecture.) Postsurgicallythe template can be used to determine the de-gree of tissue maturation and to more criticallydetermine the timing of the delivery of the defini-tive restorations.

ACKNOWLEDGEMENTS

The authors would like to thank Dr Hyman Smuk-ler and Dr Steven M. Morgano of the Boston Uni-versity School of Dental Medicine. Without theirinput, advice, and guidance, this manuscriptwould have never been written. We would alsolike to acknowledge Dr Girolamo Stellino’s contri-bution to the development of the technique pre-sented.

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REFERENCES

1. Glossary of Periodontal Terms, ed 4. Chicago: AmericanAcademy of Periodontology, 2001:11.

2. Friedman N. Periodontal osseous surgery: Osteoplastyand ostectomy. J Periodontol 1955;26:257–259.

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4. Ochsenbein C. A primer for osseous surgery. Int J Perio-dontics Restorative Dent 1986;6:8–47.

5. Scutellà F, Landi L, Stellino G, Morgano SM. A surgical-guide template for crown lengthening procedure: A clini-cal report. J Prosthet Dent 1999;82:253–256.

6. Bragger U, Lauchenauer D, Lang NP. Surgical lengtheningof the clinical crown. J Clin Periodontol 1992;19:58–63.

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8. Coslet JC, Vanarsdall RL, Weisgold A. Diagnosis and classi-fication of delayed passive eruption of the dento-gingivaljunction in the adult. Alpha Omegan 1977;70:24–28.

9. Gargiulo AW, Wentz FM, Orban B. Dimensions and rela-tions of the dentogingival junction in humans. J Periodon-tol 1961;32:261–267.

10. Cohen DW. 1962. [Au: please provide complete refer-ence for Cohen.]

11. Kois JC. New paradigms for anterior tooth preparation.Rationale and technique. Oral Health 1998;88:19–30.

12. Wagenberg BD, Eskow RN, Langer B. Exposing adequatetooth structure for restorative dentistry. Int J PeriodonticsRestorative Dent 1989;9:322–331.

13. Maynard JG Jr, Wilson RD. Physiologic dimensions of theperiodontium significant to the restorative dentist. J Perio-dontol 1979;50:170–174.

14. Ingber JS, Rose LF, Coslet JC. The “biologic width”: Aconcept in periodontics and restorative dentistry. AlphaOmegan 1977;70:62–65.

15. Rosenberg ES, Garber DA, Evian CI. Tooth lengtheningprocedures. Compend Contin Educ Dent 1980;1:161–172.

16. Kois JC. Altering gingival levels: The restorative connec-tion I. Biologic variables. J Esthet Dent 1994;6:3–9. [Au:please confirm reference. It was not found online.]

17. Herrero F, Scott JB, Maropis PS, Yukna RA. Clinical com-parison of desired versus actual amount of surgical crownlengthening. J Periodontol 1995;66:568–571.

18. Bell LA, Valluzzo TA, Garnick JJ, Pennel BM. The pres-ence of “creeping attachment” in human gingiva. J Perio-dontol 1978;49:513–517.

19. van der Velden U. Regeneration of the interdental soft tis-sues following denudation procedures. J Clin Periodontol1982;9:455–459.

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