Dentistry

Primary anterior tooth replacement with a fixed prosthesisusing a precision connection system: A case reportGiselle Rodrigues de Sant'Anna, DDSV Renafa de Oliveira Guare, DDSVCelia Regina Martins Delgado Rodrigues, DDS, MSD,Antonio Carlos Guedes-Pinto, DDS, MSD, PhD''

This article describes a novel technique tor primary anterior tooth rGplacement using a new prosthetic sys-

tem that requires minimally invasive dental preparation. The technique was used to restore the dentition of

a 42-month-old girl with extensive loss of tooth substance, (Quintessence Int 2002:33:303-308)

Key words: adhesive prosthesis, primary tooth, prosthesis, space maintainer, tooth loss

Anterior primary tooth loss frequently occurs inyoung children (ages 6 to 36 months) despite allthe routine preventive measures used in pédiatrie den-tistry. Particularly susceptible to this phetiomenon arethe maxillary incisors, usually as a consequence oftrauma,'-^ nursing-bottle caries, or rampant caries (eg,early childhood caries),''^''"" Early tooth loss can causeproblems, both esthetic and functional, in permanenttooth formation and eruption as a result of tonguethrusting in the edentulous space and as a consequenceof harmftil habits.'-^''"''' Dentists experience difficulty inresolving these esthetic and functional problems in pa-tients during early childhood,^*'^ ''

The use of removable functional space maintainersis often recommended as a therapeutic approach tothe treatment of these problems."-'^ Removable appli-ances are useful for replacing several lost teeth; how-ever, when a small number of teeth is concerned, theneed for cooperation of children for a long time andperiodic adjustments are disadvantages,'"'' This treat-ment is also not suitable for very young children be-cause of possible deleterious consequences to thechild's stomatognathic system (eg, tounge position al-

'Spedalisl, Department of Ortrtodontics and Pédiatrie Dentistry, University

ot Sâo Paulo, Sâo Paulo, Brazil

'Graduate Student, Department of Orthodontics and Pédiatrie Dentistry,

Uriuersity of Sâo Paulo, Sâo Paulo, Brazil.

=Prafessor,, Department o( Orthodontics and Pediatrio Dentistry, University

of Sac Paulo, Sao Pauio, Brazil.

'Professor and Chairman, Department of Orttiodontics and Pédiatrie

Dentistry, University of Sâo Paulo, Sâo Paulo, Brazil,Reprint requests: Dra Giselle Rodrigues de SantAnna, Departamentode Ortodontia e Odonfopediatr ia, Universidade de Sâo Paulo,Av Prof Lineu Prestes 2221. Sao Paulo, Brazi l , CEP 05508-900.E-mail: giEeliesantanna@tiotmaii.com

teration, traverse growth interference during the per-manent incisors, eruption phase),''

Fixed space maintainers, if properly designed, are lessdamaging to the oral tissues than removable spacemaintainers and less of a nuisance to the patient, andthus more appropriate for long periods of space mainte-nance,''* A resin-bonded prosthesis without rigid con-nectors permits normal physiologic premaxillary growthbecause it does not form a rigid connection between thepontics.'*' Although fixed prosthetic replacement of pri-mary teeth with resin-bonded prostheses is not commonfor cost reasons, the method may be beneficial in certaincases,' The use of a fixed prosthesis may be consideredfor these situations, a procedure that has been demon-strated to achieve satisfactory results in all aspects,"

The use of fixed prostheses in children is limited bythe arch modifications that result from the develop-ment of primary and mixed dentition occlusions.However, a period of stability exists in which fixed ap-pliances may be used. This period, when children arebetween the ages of 3,0 and 5,5 years, is the time inwhich the primary arch is completed and the sagittaland transverse dimensions are unaltered,'-

Currently available fixed prostheses, however, oftendamage the structure of abutment teeth, a consequencethat conflicts with all the objectives of modern preven-tive dental philosophy. The Crownless Bridge Workssystem {CBW Co) was developed in 1993 by NijmegenUniversity as an advancement of the Universal DentalAnchorage (UDA) Plus system (Aguda) and to ofier analternative prosthesis that inflicts minimal damage tosound teeth,̂ *' With this system, it is possible to replaceboth anterior and posterior teeth with a strong pros-thesis of single or multiple pontics and at the sametime, to preserve abutment teeth,̂ "

Quinte303

• de Sant'Anna el al

Fig 1 Rampant caries in a 42-month-oid girl. Fig 2 Radiographic evaiuation ol Ihe anterior teeth.

Fig 3 Resull after endodontic treatnnent and placemeni of resincomposite restorations.

Fig 4 Setting oí the anchor position with a parallelomelei anddrilling templates constructed on a cast

The CBW system combines techniques derivedfrom the UDA prosthesis system with a system thatutilizes precision connectors attached to the abut-ment teeth with pins cemented in the proximal as-pgf-t 18,21,22 fĵ e CBW system combines two retentiontechniques, the anchorage and the adhesive systems.In addition to the esthetic advantages provided bythe minimal need to alter support teeth, the systemoffers the following advantages over conventionalprostheses:

1. Minimally invasive abutment preparation2. Improved distribution of ioads compared to that

offered by adhesive prostheses3. Few periodontal problems, because of the ab-

sence of margins4. No alterations in occlusion5. Reversible and easily repairable treatment6. Reduced cost and work time7 iVlinimal stress for the patient

Similarly to the UDA system, the CBW system usesa titanium precision anchor and a connector ce-

mented into the proximal surface of the supporttooth.''•'̂ •̂ '•2^ Aithough the system utilizes three typesof anchors and connectors, the smallest (type III) of-fers the greatest possibilities for pédiatrie dentistry.

The purpose of this article is to present a noveltechnique for primary anterior tooth replacement witha new prosthetic system that requires minimally inva-sive dentai preparation.

CASE REPORT

A 42-month-old girl with extensive dental structureloss in the anterior and posterior regions presentedwith an altered vertical dimension of occlusion, a situ-ation resulting from poor oral hygiene and lack of di-etary control. A patient history was talien and ciinicaiand radiographie evaluations were made, affer whicha treatment plan was established (Figs 1 to 3). The pa-tient's mother was instructed in hygiene and dietaryhahits for control of the problem and was informed ofthe proposed treatment with the new system, afterwhieh she provided her written consent.

304 Nirmber4. 2002

• de Sant'Anna et al

Fig 5 Initial demarcation for the anchor channe Fig 6 Retention ohanneis made with a special low-speed hand-piece and fhe appropriate drili for each anchor The handpieoeand dnil must be perpendicuiar to the proximal surtace.

Fig 7 CBW kit, composed ot precision anchors. Fig 8 Cementation of the anchor with an adhesive system .

Initially, the altered verticai dimension of occlusionwas reestablished through gradual restoration of theposterior teeth through adhesive techniques. As a con-sequence, esthetic rehabilitation of the anterior teethwas achieved. Extraction of tooth 6f (F) and endodon-tic treatment of teeth 52(D), 5f(E), and 62(G) werenecessary because of the presence of extensive cariesand pathologic lesions. Resin composite crowns madewith a plastic matrix' and retained by cementednickel-chromium macroretentîon cast posts^'' wereused to recover the lost coronal tooth structure.

Drilling templates constructed on a cast were usedas a guide to allow optimal reproduction of the loca-tion for precision parallel setting of the anchor. Theywere achieved using a parailelometer on the proximalsurfaces, resulting in a unique patb of insetiion and re-moval (Fig 4). Following demarcation with a round di-amond bur (0.9 mm), the retention anchor channelson the abutment teeth were prepared with specializedCBW drills, each of which is designed for a specificanchor and rotary instrument (Figs 5 and 6). TheCBW type III anchor was selected because of its size,suitable for the proportions of the primary teeth (Fig

7). The anchor, when in position, should be located atleast 1 mm below the occlusal or incisai surface, ide-ally coinciding with the contact point of the abutmenttooth, and should also be completely seated againstthe proximal surface of the abutment tooth before ce-mentation with the anchor holders (Fig 8).

The adhesive system and resinous cement were usedto achieve maximum adhesion, while the anchor hold-ers provided anchor alignment and parallelism, result-ing in a unique axis of insertion and removal (Fig 9}.

An impression was taken, and stone casts with ana-log of the system were fabricated to be sent for labora-tory procedures (Fig 10). The prosthesis was manufac-tured and adjusted in the usual manner and without atrial appointment, because an acrylic resin templatewas used to test the path of insertion and removal be-fore the impression was made (Figs If and 12). Theuse of a provisional crown was recommended for im-provement of the child's self-esteem.

Following evaluation of the adaptation of the pros-thesis, all the internal metallic surfaces were sand-blasted with aluminum oxide (Fig 13). Abutment teethwere cleaned with pumice, and the anchor bodies

Qui"'-305

de Sanl'AnriB et ai

Fig 9 Anchor paraiieiism provided by special piiers Fig 10 Siiícone impression made with tlie anaiog pieces in posi-tion

Fig 11 Use ol an acrylio resin guide to test the path of insertionand removal

Fig 12 Lingual view of the prosthesis on the cast

Fig 13 internai aspect of the metailic components of the pros-thesis. Note the aluminum o>!ide sandblasting.

were cleaned with ethyl alcohol, A surfactant was ap-plied to the resin composite crowns to promote the re-action of the material with the adhesive system, Abonding system and resin cement were used to hondthe CBW prosthesis to the anchor bodies and to theetched abutment teeth to obtain the greatest possihleadhesion {Figs 14 and 15),

The patient's clinical appearance 6 months afterplacement of the prosthesis is shown in Figs 16 and 17,The patient exhibited clinically healthy gingiva withno signs of periapical lesions in the incisors.

Radiographie evaluation 6 months after cementa-tion of the prosthesis revealed no signs of recurrentcaries in the abutments at the crown margins or ce-ment washout at the anchors; tbe periapical patho-logic lesion was controlled (Fig IS),

In the initial radiograph, the permanent lateral in-cisor germ was at a lower position than the permanentcentral teeth. In the radiograph taken 6 months later,there is an overlapping image, demonstrating the per-manent central incisor in a lower position. This occur-rence is compatible with the patient's age as well asthe visible osseous résorption.

306

• de Sani'Anna et al

Fig 14 Buccal view immediately atter cementation of Ihe pros-thesis

Fig 15 Lingual view immediately atter cementation ot the pros-thesis.

Fig 16 Buccal view 6 months after cementation ot the prosthe- Fig 17 Occlusal view 6 months atter cementation of the prosthe-

I! The patient is under eonstant observation; if anyil change occtirs as a result of growth or pe rmanen t too thil eruption, the prosthesis can he transformed into a can-It! tilever appl iance with no joint he tween the abutments11̂ and the pontics, to prevent disruption of maxillaryB development. Indeed, periodie appointments are neces-

sary to assess the appliance integrity.

DISCUSSION

Early primary tooth loss can disrupt space mainte-nance and occlusion; permanent tooth developmentand eruption patterns, causing developmental distur-bances; the child's emotional development, because Fig 18̂^ "^'^'^^it^^^^í^.^íZil^^lf^.^fJ^f^ií^^^the first years of childhood strongly influence individ-ual development; and an individual's personal charac- meni (lowerright).tcristics because of esthetic defects, especially if thesedefects are visible during speech and laughter,-'

Pédiatrie dentistry constantly searches for solutionsto loss of tooth substance or anchorage. Little improve-ment, however, has been made in the old-fashioneddental practice of sacrificing abutment tooth structures.

g gp p (pp )ately alter endodohtic treatment (upper r/gW/immediately aftercementation ol the prosthesis (iower ieñ). and 6 months posttreat-

Quir- 307

• de Sanl'Anna et ai

a practice that directly contradicts the philosophy ofmodern preventive dentistry. The CBW system is a re-habilitation alternative that has been developed for theplacement of crownless prostheses that do not inflictdamage to sound teeth. However, reports of clinicalfollow-up of CBW prostheses have not been publishedyet, which must be considered a disadvantage,^"

Although the technique described is not quite sim-ple, it is effective despite the numerous steps involvedin the clinical and laboratory procedures. The costs in-volved are limitations. The child's ability to cooperate^'must also be considered, because of the long chair timeinvolved and the elaborate technique.

It is worth reiterating that tbis technique is preven-tive, because it is a minimally invasive method.^" Ifvital primary teeth are affected, the size and shape ofthe pulp chamber must be considered in relation tothe length of the anchor (1,6 mm) as well as the reper-cussions of pulpal proximity,̂ "'̂ '

CONCLUSION

The use of the CBW system in the patient described inthis report resulted in a clinically successful recoveryof esthetics and function, preventing tongue thrusting,open bite, speech difficulties, and chewing difficulties.The child's self-esteem and oral heaith also improved.However, the 6-month follow-up is not yet sufficientto consider the treatment a success.

The proposed technique represents another promis-ing minimally invasive alternative for prosthodonticrehabilitation of early anterior primary tooth loss.

ACKNOWLEDGMENTS

The authori Ihank CBW of Brazil for providing the material used inthis ciise.

REFERENCES

1, Chang JZC, Chen PHC, Kuo S-C. An appliance to replaceprematurely losl maxillary anterior teeth using double stain-less steel crowns on abutment teeth, J Clin Pediatr Dent1999:23:285-288.

2, Citron CI, Esthetics in pedialric dentistry. NY State Dent J1995 ;61:30-33.

3, Hübet CT. Resin-bonded retainer for replacement of anavulsed primary incisor: A case report. Quintessence Int1997;28:337-339,

4, Croll TP. Bonded composite resin crowns for primary in-eisors: Technique update. Quintessence Int 1990;21:153-157.

5, Fass EH. Is bottle feeding of milk a factor in dental earies?ASDCJ Dent Child 1962¡29:245-251,

6. Grosso FC, Primary anterior strip crowns: A new techniquefor severely deeayed anterior primary teeth. J Pedod 1987;

11:375-384.

7 Judd PL, Kenny JD, Johnston DH, Yaeobi R, Compositeresin short-post technique for primary anterior teeth, ) AmDent Assoc 1990;120:553-555,

8. Richardson BD, Cleaton-Jones PE. Nursing bottle caries. JPediatr 1977;60:748-749,

9, Snawder KID, Gonzalez WE Jr Management of severelydiseased primary anterior teeth. J Dent Child 1975;42:181-185.

10, Wiedenfild KR. An esthetic technique for veneering anteriorstainless steel crowns with composite resin, J Dent Child1994;61:321-326,

11, Yiu CKY, Wei SH. Management of rampant caries in chil-dren, Quintessenee Int 1992;23:159-168,

12, Bengtson AL, Bengtson NG, Mathias RS, Benassi LRDC.Ponte fixa em Odontopediatria. Rev Paulista Odontol 1989;11:38-41.

13, Liégeois F, Limme M, Modified bonded bridge space main-tainer, J Gin Pediatr Dent 1999;23:281-284,

14, Orsi IA, Faria JFR, Bolsoni I, Freitas AC, Gatti P, The use ofa resin-bonded denture to replace primary incisors: Case re-port, Pediatr Dent 1999;21:64-66.

15, Hugo B, Lücken Versorgung mittels Stift Adhäsivbrücke undKomposita- rekonstruktion eines stark zerstörten Zahnes,Quintessenz 1992;45:39-57

16, Sandhaus S, Das mehrfunktionelle Ankersystem. Quintes-senz 1985;4:685-697

17, Katz GB. "Cover-denture" for children, Quintessenz1982:33:1187-1193,

18, Qudeimat MA, Fayle SA, The longevity of space maintain-ers: A retrospective study, Pediatr Dent 1998;20:267-272.

19, Baume LJ. Physiologic tooth migration and its significancefor development of occlusion, J Dent Res 1959;29:351-337

20, Olschowsky W. Minimalinvasive Bruckenprothetik:Crownless Bridge Works (CBW), Quintessenz 1998;49:917-929,

21, Davidson CL, Hansson TL, Krahbendam CA, An alternativemethod of tooth replacement. Quintessence Int 1987;18:139-149.

22, Walsh JF. Pedodontic prosthesis, J Prosthet Dent 1976;33:13-16,

23, Wilwerding C, An alternative method of canine fixed partialdenture retainers. Quintessence Int 1990;21:271-273.

24, Wanderley MT, Ferreira SLM, Rodrigues CRMD, RodriguesLE Jr, Primary anterior tooth restoration using posts withmacroretentive elements. Quintessence Int 1999;30:432-436,

25, Joho JP, Maréchaux SC. Prosthetic prohlem and solution inthe primary dentition: Report of a case, ASDC J Dent Child1980;47:50-52,

26, Pinkham JR. Behavior management of children in the den-tal office. Dent Clin North Am 2000;44:7I-86,

27, Pinkham JR, Pédiatrie Dentistry: Infancy ThroughAdolescence. Philadelphia: Saunders, 1988.

308 Volume 33. Number 4. 2002