Biotipos periodontales


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Biotipos periodontales

  1. 1. g i n g i va l b i ot y p e s c da j o u r n a l , vo l 3 6 , n º 3 r Thick vs. Thin Gingival s Biotypes: A Key Determinant in Treatment Planning for Dental Implants richard t. kao, dds, phd; mark c. fagan, ms, dds; and gregory j. conte, ms, dmd a bstract  During the treatment planning process, it is important to recognize differences in gingival tissue can affect treatment outcomes. The concept that thick and thin gingival biotypes have different responses to inflammation and trauma was previously introduced. In this paper, this concept is expanded in that gingival biotypes dictate different procedures for implant site preparation. With appreciation of these differences, preparatory steps can be taken to create a more ideal implant placement site. Pauthors acknowledgment reviously, the importance of Thick and Thin Gingival BiotypesRichard T. Kao, DDS, PhD, This paper is dedicated to taking into consideration the Historically, Ochsenbein and Milleris in private practice in Drs. Ivan Ancell and Joseph differences in gingival tissue have discussed the importance of “thickCupertino, Calif., associate Zingale who helped guide during treatment planning has vs. thin” gingiva in restorative treat-clinical professor, the authors during our been emphasized. Specifically, ment planning.1 In a population study,University of California, periodontal training in the it was pointed out how thick and thin thick periodontal biotypes (85 percent)San Francisco, and development and thoughtassociate adjunct process behind this paper. gingival biotypes respond differently to were found to be more prevalent thanprofessor, University inflammation, restorative trauma, and thin scalloped forms (15 percent).3of the Pacific Arthur A. parafunctional habits.1,2 These traumatic Subsequently, the authors published aDugoni School of events result in various types of periodon- paper that further analyzed thick andDentistry, San Francisco. tal defects, which respond to different thin tissue biotypes in terms of theirMark C. Fagan, MS, DDS, treatments. The authors also pointed gingival and osseous architecture.2is in private practice in out how periodontal surgery techniques Thick gingival tissue is probablySan Jose, Calif., assistant have made it possible to change a thin the image most associated with peri-clinical professor, gingival biotype into a thick gingival odontal health (figure 1a, table 1) .University of California, form. This provides a more favorable The tissue is dense in appearance withSan Francisco. restorative environment and increases a fairly large zone of attachment. TheGregory J. Conte, MS, the predictability of treatment outcomes. gingival topography is relatively flatDMD, is in private practice In this paper, the authors extend with the suggestion of a thick underly-in San Francisco. their earlier observations of thick vs. thin ing bony architecture. Surgical evalua- gingival tissues and describe why it is tion of these areas often reveals important to appreciate tissue biotypes relatively thick underlying osseous during implant treatment planning. forms (figure 1b) . m a r c h 2 0 0 8   1 93
  2. 2. g i n g i va l b i ot y p e s c da j o u r n a l , vo l 3 6 , n º 3 table 1 Characteristics of Thick Gingiva n Relatively flat soft tissue and bony architecture n Dense fibrotic soft tissue n Relatively large amount of attached gingiva n Thick underlying osseous form n Relatively resistant to acute trauma 1 a. n Reacts to disease with pocket f igure s 1 a - b. The clinical presentation of thick 1 b. formation and infrabony defect gingiva and the type of osseous architecture associated formation with this gingival tissue type. table 2 Characteristics of Thin Gingiva n Highly scalloped soft tissue and bony architecture n Delicate friable soft tissue n Minimal amount of attached gingiva n Thin underlying bone characterized by 2a. 2 b. bony dehiscence and fenestration f igure s 2 a - b. Clinical presentation of thin n Reacts to insults and disease with gingiva is characterized by thin friable tissue. It is gingival recession associated with clefts, perforation, and gingival recession. table 3 Comparison of Tissue Response to Inflammation, Surgery and Tooth Extraction T hick Gingival Biotype T hin Gingival Biotype Inflammation Soft tissue: Marginal inflammation; Soft tissue: Thin marginal redness cyanosis; bleeding on probing; edema/ and gingival recession f i g u r e 2 c . The osseous archi- fibrotic changes Hard tissue: Rapid bone loss tecture associated with this gingival Hard tissue: bone loss with pocket associated with soft tissue tissue type is characterized by fenestration and dehiscence. formation/infrabony defects recession Surgery Predicable soft and hard tissue Difficult to predict where tissue will contour after healing. heal and stabilize Tooth Extraction Minimal ridge atrophy Ridge resorption in the apical and lingual direction Thin gingival tissue tends to be tration and dehiscence (figure 2c) . that current periodontal surgical tech-delicate and almost translucent in ap- In the authors’ previous paper, it niques have the potential to improvepearance (figures 2a-b, table 2) . The was suggested that since these two tissue quality, thereby enhancing thetissue appears friable with a minimal tissue biotypes have different gingival restorative environment. The paradigmzone of attached gingiva. The soft and osseous architectures, they exhibit shift proposed was that by taking intotissue is highly accentuated and often different pathological responses when consideration the gingival tissue biotypesuggestive of thin or minimal bone subjected to inflammatory, traumatic, during treatment planning, more appro-over the labial roots. Surgical evalu- or surgical insults2 (table 3) . These priate strategies for periodontal man-ation often reveals thin labial bone different responses dictate different agement may be developed, resulting inwith the possible presence of fenes- treatment modalities. It also was noted more predictable treatment outcomes.19 4  m a r c h 2 0 0 8
  3. 3. c da j o u r n a l , vo l 3 6 , n º 3Tissue Biotype in Implant TreatmentPlanning If osseous and gingival tissues are dif-ferent for thick and thin tissue biotypes, f igure 3 a . Tooth No. 9 has a fractured root. f i g u r e 3 b. The crown is removed and the anchorit seems logical that these distinctions post is placed into the root tipwould significantly influence implant sitepreparation and treatment planning. Thisis consistent with previous observationsthat the stability of the osseous crest andsoft tissue is directly proportional to thethickness of the bone and gingival tissue.4,5Thick bony plates associated with thick bi-otypes and thin plates with potential fen-estrations and dehiscence associated withthin biotypes respond differently to ex- figure 3c. The anchor post is placed through f i g u r e 3 d . The extracted root. This technique istraction and have a different pattern of os- a perforation in an impression tray containing bite advantageous since there is no force placed on theseous remodeling following this procedure. registration material. Using the tray as a base, the an- socket and surrounding bone chor post is ratcheted such that the root is elevated.The trauma induced by the extraction pro-cedure is more likely to result in fracture ofthe labial plate in the thin biotype than in alveolar plates. Possible strategies contact bite registration and impressionthe thick one. Also, the remodeling process that should be considered include: material for the adjacent teeth. Afterthat follows over the next few months will n Minimizing leveraging forces the impression material has set, theresult in more dramatic alveolar resorp- toward the thin labial plate. Most anchoring device is ratcheted againsttion in the apical and lingual direction for of the manipulation should be fo- the top of the quadrant tray. This strat-the ridge associated with thin biotypes. cused on the interproximal area. egy is atraumatic and applies no forces Even after initial alveolar ridge n Sectioning the root(s) from on the surrounding alveolar bone.remodeling, the gingival tissue and bone the tooth, when possible, to im- Atraumatic extraction and preserva-are more likely to continue to recede, prove the likelihood for elevation. tion of the alveolar plate are essentialespecially if the implant is labially in- n Using periotomes to expand and if the site is to be used for implantclined. This underscores the importance elevate the tooth with controlled force placement. Excessive force is likely toof appreciating gingival tissue biotypes focused on the periodontal ligament fracture the alveolar plate and result induring implant treatment planning. space. The placement and elevation force bone resorption and unpredictable boneFurthermore, when these tissue bio- should be focused on the interproximal healing. This is more pronounced withtypes are carefully considered, various space so leverage force is exerted on the thin alveolar plate associated withperiodontal and surgical strategies can either the buccal or lingual plate. thin gingival biotypes. When compro-be employed to improve the treatment n Using a ratchet extraction device mise of the alveolar plate is suspected,outcome either by minimizing alveolar to apply reciprocating force on adjacent it is essential to utilize ridge preserva-resorption or by providing a better tissue teeth while extruding the amputated tion or augmentation protocols.environment for implant placement. root tip out the socket (figure 3) . This may be the most effective and atraumatic Ridge Preservation in Thick vs. ThinExtraction of Teeth in Thick vs. Thin approach for the broken tooth. The tooth BiotypesBiotypes is amputated to the level of the cemen- Prevention of postextraction alveolar Though extractions should al- toenamel junction. After preparation bone loss is critical in assuring implantways be atraumatic, teeth with thin of a post space, an “anchoring” device success. Given the thin alveolar plate as-gingival biotypes merit more atten- is used to engage the root. This device sociated with thin periodontal biotypes, ittion due to their association with thin is passed through a quadrant tray with is not unusual to see more extensive ridge m a r c h 2 0 0 8   1 95
  4. 4. g i n g i va l b i ot y p e s c da j o u r n a l , vo l 3 6 , n º 3f ig ur e 4a. Lower left lateral incisor No. 23 was f igure 4b . Bone graft material and a resorbable f i g u r e 4 c. Re-entry at five months, whichextracted and extensive bone loss was present. A membrane were placed, (Biomend Extend. Zimmer illustrates bone regeneration up to the top of the12-mm tenting bone screw was placed to support the Dental. Carlsbad, Calif.) bone screw.graft material and prevent collapse of the membrane.remodeling when compared to the thicker to the osseointegration of the dental ramus or mandibular symphysis. Allograftalveolar plate associated with thick bio- implants. For that reason, slow resorp- block grafts can be obtained from severaltypes. Not only is atraumatic extraction tion graft materials such as xenografts commercial providers. The advantage ofcritical to minimize this postextraction and nonresorbable alloplastic materials this technique is that the graft is placedremodeling, it is important to consider (durapatite, hydroxyapatite) should be as a block instead of in particulate form,strategies to preserve the alveolar bone, avoided. When there is excessive volume providing increased structural support.such as socket preservation or ridge of nonresorbable graft materials, there A case of block grafting is presentedpreservation procedures. A number of is inadequate room for bone ingrowth where there is a narrowed anteriorstudies have shown that without inter- to provide implant osteointegration. maxillary ridge defect (figure 5a) . Thesevention, significant alterations in most Additionally, the ridge preservation situations generally require two-stageextraction ridge dimensions will occur.6-9 strategy is only successful if the graft ma- surgical procedures that included a bone This loss can be 1.5 to 2.0 mm over the terial is retained in the extraction socket. graft surgery followed by implant place-first 12 months with most loss occurring A variety of approaches can be utilized to ment after graft healing. In this situa-during the initial three months.9 A variety achieve socket closure. These include the tion, it is critical that soft tissue incisionsof approaches can be employed to address use of barrier membranes, tenting pins, be carefully planned to allow for flapthis problem, but most involve grafting collagen plugs, connective tissue grafts, relaxation over the increased volumethe extraction socket and using mem- free gingival grafts, acellular dermal gained by the graft and to ensure ten-branes to support missing/perforated grafts, and advancement of the buccal sionless primary closure. Once adequatebony walls. Ridge preservation should flap. An advanced case of socket preserva- access was gained, the graft and recipientbe considered for most thin biotype tion with regeneration of the labial plate bed were prepared to obtain intimate,cases and in thick biotype cases where and vertical dimension is seen in figure 4 . broad contact between the surfaces.excessive trauma or a previous history Whereas simple cases with intact buccal The recipient bed was perforated toof endodontic surgery/fistula tracts may and lingual plates can be easily man- enhance revascularization and the grafthave compromised the alveolar plate. aged with grafting and socket coverage, was stabilized using fixation screws to Classically, socket or ridge preserva- advanced cases may require space-main- maintain close bone contact and preventtion involves the use of a graft material taining devices such as tenting pins and graft rotation (figure 5b) . Adequate prima-placed in the socket followed by a variety membranes. All of these options work to a ry fixation is essential for graft survival.of other substances such as demineralized certain extent and the selection should be Particulate bone can be packed aroundfreeze-dried bone allograft, mineralized based on individual cases/requirements. the block and a resorbable collagenfreeze-dried bone allograft, xenograft When excessive bone is lost to membrane can be placed over the entire(mostly of bovine source), and alloplas- resorption, leaving a narrow ridge with graft. The soft tissue flap is then advancedtic materials (b-tricalcium phosphate, a large buccal deficiency or decreased and sutured for primary closure. Afterdurapatite, hydroxyapatite). Since the site vertical height, a block graft is gener- a healing period of five to six months,will be used for implant placement ap- ally the technique that yields predict- the site can be re-entered and integra-proximately three months to four months able results.10-11 The block graft material tion of the graft to the recipient boneafter grafting, it is important to select a can be of autologous or allograft origin. confirmed. Using an appropriate surgi-graft material that resorbs quickly since Autologous graft material is commonly cal stent, implants can then be properlyonly newly formed bone will contribute harvested from either the mandibular placed into the widened ridge (figure 5c) .19 6   m a r c h 2 0 0 8
  5. 5. c da j o u r n a l , vo l 3 6 , n º 3f ig ur e 5a. Extensive defect noted upon flap f igure 5 b . The area was prepared and a block f i g u r e 5c. Re-entry at six months. Note theelevation. allograft was trimmed and fixated with two bone excellent ridge width obtained and the ideal screws (J Block Cortico-Cancellous Bone Allograft, implant placement in the augmented site. Zimmer Dental). pulled coronally, possibly resulting in a lack of adequate attached tissue, and thereby creating a “thin” case that will compromise future implant placement. A technique for covering the socket after tooth extraction using a pediculated connective tissue graft was described by Mathews.12 Utilizing this closure tech- nique over the grafted socket permitted complete soft tissue coverage. Addition-figure 6a. The initial defect after tooth extraction. f igure 6 b. The defect was filled with FDBA and ally, it maintained both vertical andThe defect is mainly a three-wall defect with almost a tenting pin was placed for space maintenance. horizontal soft tissue components, andcomplete loss of facial bone. increased the thickness of facial attached tissue (figure 6c) . After healing for five to six months, the site was re-entered and an implant was placed (figure 6d) . This case illustrates the transformation of a severely “thin” defect into a more advantageous “thick” periodontium. Immediate Implants in Thick vs. Thin Biotypes Whether a practitioner chooses tof ig ur e 6c. A pediculated connective tissue graft f igure 6 d . On re-entry, there is both adequatewas used to cover the grafted defect, maintaining volume of hard, as well as soft, tissue for implant place an implant as a delayed or immedi-soft tissue height and width. placement. ate treatment will depend on the condi- tions of each case. A delayed implant In this second case of deficient alveo- space, a tenting pin was placed in the approach might be taken when therelar ridge, it is essential to rebuild both socket in an orientation to help support is not enough thickness in periodontalthe hard and soft tissue components in a both the facial and vertical dimensions. tissues to predictably minimize alveolarsingle procedure to improve the esthetics Particulate freeze-dried bone allograft resorption secondary to healing, or a lackand to minimize surgical visits (figure 6a) . material was packed into the socket of anchoring bone to ensure stabilization. This case illustrates a three-wall defect, around the tenting pin, slightly overfill- The decision is also dependent on thewhich has better regenerative potential ing the defect (figure 6b) , and a resorb- practitioner’s comfort level in availablethan the one-wall type discussed previ- able collagen membrane was trimmed reconstructive techniques. For a thinously. For this defect, particulate bone can and placed over the graft material. biotype case, practitioners must be awarebe used as long as two critical compo- Soft tissue closure over the mem- of the possibility of significant resorption,nents of regeneration are included: space brane and graft is critical for proper which may have an impact on esthetics.maintenance and adequate soft tissue healing. If the facial flap is advanced over Furthermore, the loss of peri-implantclosure. In order to maintain the defect the defect, the vestibular tissue will be structures may result in thin, trans- m a r c h 2 0 0 8   1 97
  6. 6. g i n g i va l b i ot y p e s c da j o u r n a l , vo l 3 6 , n º 3 tion and provide a more favorable tissue environment for implant placement. This is especially important in thin periodontal biotypes where the thin alveolar plate is highly susceptible to remodeling. Addi-f ig ur e 7 a . Initial presentation of maxillary left f igure 7 b . Incisal view of immediate implant tionally, these techniques when appropri-central with fractured root. Relatively minor facial placement after tooth extraction.inflammation and recession are present. ately applied can save on treatment time and cost for patients. f igure 7 c . Radiograph of r e f e r e nce s implant prior to 1. Ochsenbein C, Ross S, A re-evaluation of osseous surgery. implant exposure. Dent Clin North Am 13(1):87-102, January 1969. 2. Kao RT, Pasquinelli K, Thick vs. thin gingival tissue: a key determinant in tissue response to disease and restorative treatment. J Calif Dent Assoc 30(7):521-6, July 2002. 3. Olsson M, Lindhe J, Periodontal characteristics in individu- als with varying forms of the upper central incisors. J Clin Periodontol 18:78-82, 1991. 4. Tarnow DP, Magner AW, Fletcher P, The effect of the distance from the contact point to the crest of bone on the f igure 7 d . Final crown restoration. presence or absence of the interproximal dental papilla. J Periodontol 62:995-996, 1992. 5. Maynard JG Jr, Wilson RD, Physiologic dimensions of thelucent tissue over the implant, which mation, a treatment plan was developed periodontium significant to the restorative dentist. J Perio-appears grayish, especially if the facial that called for extraction of the tooth and dontol 50:170-4, 1979.plate is lost and implant threads are immediate implant placement (figure 7b) . 6. Atwood DA, Postextraction changes in the adult mandible as illustrated by microradiographs and mid-sagittal sectionexposed. In these cases, further bone After hard tissue grafting to fill the and serial cephalometric roentgenographs. J Prosthet Dentand soft tissue grafting procedures may facial gap of the socket, closure of the 13:810-6, necessary. However, once an im- implant-socket was completed with a 7. Lekovic V, Kenny EB, et al, A bone regenerative approach to alveolar ridge maintenance following tooth extraction. Jplant is in place, it may be difficult to pediculated connective tissue graft.12 A Periodontol 68:563-70, 1997.regain pre-extraction tissue contours. radiograph (figure 7c) was taken prior 8. Pietrokovski J, Massler M, Alveolar ridge resorption follow- In a thick biotype environment, imme- to exposure of the implant. The implant ing tooth extraction. J Prosthet Dent 17:21-7, 1967. 9. Schropp L, Wenzel A, et al, Bone healing and soft tissue con-diate placement of an implant can be com- was then exposed and the patient was tour changes following single-tooth extraction: a clinical andpleted with predictable results.13 There also referred back to his restorative dentist for radiographic 12-month prospective study. Int J Periodonticsis evidence that placement of an immedi- placement of the final crown (figure 7d) . Restorative Dent 23:313-23, 2003. 10. Levin L, Nitzan D, Schwarz-Arad D, Success of dentalate implant can help preserve the osseous implants placed in intraoral block bone grafts. J Periodontolstructures.14 Even in cases where there is Summary 78(1):18-21, 2007.relatively thick tissue present, simultane- In this paper, the authors continue 11. McCarthy C, Patel RR, et al, Dental implants and onlay grafts in the anterior maxilla: Analysis of clinical outcome. Int Jous soft and hard tissue preservation/aug- to develop the thesis that evaluation of Oral Maxillofac Implants 18(2):238-41, 2003.mentation techniques along with immedi- gingival tissue biotypes is important 12. Mathews D, The pediculated connective tissue graft: a tech-ate implant placement may be necessary in treatment planning. Since thick and nique for improving unaesthetic implant restorations. Pract Proced Aesthet Dent 14(9):719-24, achieve the best esthetic outcome. thin gingival biotypes are associated 13. Sammartino G, Marenzi G, et al, Aesthetics in oral implan- Proper treatment planning between with thick and thin osseous patterns, tology: biological, clinical, surgical, and prosthetic aspects.the implant surgeon and restorative the two tissue types will respond dif- Implant Dent Mar 16(1):24-65, 2007. 14. Dennison HW, Kalk W, et al, Anatomic considerations fordentist is essential when optimal esthetic ferently to the trauma of extraction preventive implantation. Int J Oral Maxillofac Implants 8:191-6,results are desired. An illustrative case is and have different patterns of osseous 1993.a patient presented with a fracture in the remodeling following the procedure.root of the maxillary left central incisor By understanding the nature of the to request a printed copy of this article, please con- tact/ Richard T. Kao, DDS, PhD, 10440 S. DeAnza Blvd., Suite(figure 7a) . After appropriately evaluating tissue biotype, the practitioner can employ D1, Cupertino, Calif., 95014.periodontal tissue characteristics and oth- appropriate periodontal and surgicaler necessary surgical and restorative infor- procedures to minimize alveolar resorp-19 8   m a r c h 2 0 0 8