Implant and Periodontal Considerations

 

 ALPHON  ALPHONSE SE TANGA TANGA PRADEEP PRADEEP.X  .X  BDS – CRRI  VMSDC

 

DENTAL IMPLANT AND PERIODONTAL CONSIDERATIONS

TERMINOLOGY  BIOLOGICAL CONSIDERATIONS • Soft Tissue Implant Interface • Bone Implant Interface BIOMATERIALS USED FOR IMPLANTS CLASSIFICATION CLASSIFICA TION OF IMPLANTS

CLASSIFICATION OF IMPLANT SYSTEMS TREATMENT TREA TMENT PLANNING PLANNIN G HEALING FOLLOWING FOLLOWING IMPLANT I MPLANT SURGERY  PERI-IMPLANT COMPLICATIONS AND DISEASES

 

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Dental implant is an integral component of the t he oral

implant complex, whichand alsomucosal consistsoral of supportive supp interposed keratinized soft ortive tissuesbone, and prosthetic suprastructure.  A dental implant is a permucosal device that is biocompatible bioco mpatible biofunctio nal cavity and is to placed on or within the bone associand associated atedbiofunctional with the oral provide support for fixed or removable prosthesis. Oral implantology is the science and discipline concerned themanagement diagnosis,ent design, insertion, restoration restor ationwith and for managem of alloplastic or autogenous oral structures to restore the loss of contour contour,, comfort, function, esthetics, speech and/or health of the partially or completely edentulous patient.

 

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surgery ery Implant surgery is that part of reconstructive surg that is concerned conc erned the placement of endosse endosseous, subperiost subper iosteal eal andwith transo transosseou sseous s impl implants ants for the ous, restoration and maintenance of mastication masticat ion and speech. Such surgery may also eliminate chronic pain

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related to nerve dehiscence, preserving remaining bone structure and prevent the possibility possibility of a pathologic fracture. Osseointegration: Direct structural and functional connection between ordered living bone and the surface of the load carrying implant.

 

BIOLOGICAL CONSIDERATIONS OF IMPLANTS I. Soft tissue implant interface. II. Bone implant interface.

 

Soft Tissue Implant Interface 

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The muc osal tissues around intraosseous aosseous formmucosal a tightly-adherent bandintr consistin consisting g ofimplants a dense collagenous colla genous lamina prop propria ria cover covered ed by ker keratinized atinized stratified str atified squamou squamouss epit epithelia helia.. The implant epithelium epithel ium junction junction is analogous to the  junctional epithelium around natura naturall tteeth; eeth; in that, the epithelial cells attach to the titanium implant implant by means of hemid hemidesmos esmosomes omes and basal lami lamina. na. This evidence evid ence supports the concept that a viable biologicseal can exist between the the ep epithelial ithelial ccells ells an and d the implants.

 

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 A sulcus sulcus forms around the im implant plant lined w with ith a sulcular epithelium that is co continuous ntinuous apically apically with the juncti junctional onal epith epithelium. elium. Collagen fibers are nonattached and run parallel to theimplant surfac surface, e, owing owing to tthe he lack o off cementum. Since endosseous implants are permucosa permucosal, l, the soft tissue-implant interface should be considered in their placement and maintenance. This suggests that epithelium epithel ium adheres to implant surfaces and has similar biological features of the epithelium tooth interface.

 

Bone Implant Interface The relationship relationship between between endosseous endosseous implants and and bone 

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involves involv es mechanisms mechani sms like: • Fibro-osseous integration • Osseoi Osseointeg ntegrati ration on and • Bioactive integration. Fibro-osseous Integration It is defined defi ned as “tissue “tissu e to implant contact by interposition of a healthy dense collageno collagenous us tissue between between the implant and the bone interface”. Normally, fibro-osseous union between the implant implan t surface and adjoining alveolar not desirable becau se because union formed is a weak union.bone The is formation of fibro-osseous integration is attributed to proliferation proliferatio n of connective tissue into the interface, which hampers the osseous integration process.

 

Osseointegration 

It is defined as a direct structural and functional functio nal connection between ordered living bone and the surface of the load carrying implant. Bioactive Integration It is defined as the integration which results by a physiochemical interaction between collagen of bone and hydro hydroxyapat xyapatite ite crystals of the implants. 

 

BIOMATERIALS USED FOR IMPLANTS Metals and Alloys 

a. Titanium 100 100 percent pure Titanium b. Titanium-Aluminum Titanium 90 percent  Vanadium  V anadium Aluminum 6 perc percent, ent, V Vanadium anadium 4 per percent cent c. Cobalt-Chromium Cobalt 66 percent + Chromium 27 percent + Molybdenum 7 percent d. Stainless steel Iron 70 percent + Chromium 18 percent + Nickel 12 percent e. Tantalum Tantalum 100 percent p ercent pure f. Zirconium 100 percent pure g. Gold 100 percent pure h. Platinum 100 percent pure

 

Inert Ceramics a. Aluminum oxide (Al2O3) •• Single Polycrystalline crystal. b. Zirconium oxide zircona. c. Titanium oxide. Calcium Phosphate Ceramics

Calcium Bioactivephosphate. and Biodegradable Ceramics a. Hydro Hydroxyapatite. xyapatite. b. Tricalcium phosphat phosphate. e. c. Bioglass. d. Ceramic.aluminates. e. Calcium f. Carbon. g. Carbon silicon. h. Polycrystalline glassy carbon.

 

Polymers a. Polymet Polymethy hyll metha methacryl crylate ate.. b. Polytetrafluoroethylene. c. Polyethylene. 

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d. Poly Polyethylene ethylene tetraphthalate. e. Polypropylene. f. Polyoxymethylene. g. Silicone rubber. h. Polysulfone.

 

CLASSIFICATION OF IMPLANTS Implants are classified based on: 1. Shape and form and 2. Surface characteristics. Based on the Shape and Form 1. Endosteal. 2. Subperiosteal. 3. Transosteal Transosteal.. 4. Intramuc Intramucosal osal inserts/sub inserts/submuc mucosal osal implants/sub implan ts/subderm dermal al implants. implants.

5. Endodontic Endodonti c stabilize stabilizer r.  With regard to shape, it is possible to distinguish between: a. Post or root root form implants implants—Exhibiting rotation symmetry. b. Blade implants—Extension implants.

 

The post or root root implant designs can be of th thee following types: 1. Solid tapering types. 2. Solid cylinder type. 3. Pin type. 4. Screw-shaped implant type. 5. Basket design. 6. Hollow cylinder design. The blade implant designs can be of following types: 1. Conventional blade design. 2. Vented Vented blade design.

 

Based on Surface Characteristics 1. Titanium plasma—sprayed coating. 2. Sand blasting—surface etching. 3. Laser induced surface roughening. 4. Hydrox Hydroxyapatit yapatitee coating. coating.

 

CLASSIFICATION OF IMPLANT SYSTEMS

1. Branemar Branemark k impla implant nt system system (N (Nobel obel Bio Biocar caree System System). ). 2. International team team ffor or implanto implantology logy (ITI) syst system. em. 3. Implant innovations systems. 4. Astra-dental implant system. 5. IMZ implant implant system (Int (Interpor erporee IMZ). 6. Cor Corev event ent system. system. 7. Sterios Steriosss sy syst stem. em. 8. Stryker implant system. 9. Endosteal Endosteal hollow hollow basket system.

 

TREATMENT PLANNING Clinical Assessment

Selection of cases for implants is based on the: I. Age limitations for case selection. II. Anatomic prerequisites: 1. Resorptiv Resorptivee proce process. ss. 2. Soft tissue situation. 3. Available bone. 4. Mandibu Mandibular lar canal. canal. 5. Height of bone. 6. Width of bone. 7. Bone shape (contour). 8. Length of bone. 9. Implant crown relationship. 10. Maxillary Maxillar y sinuses.

 

The Absolute Requirements Requirement s for T Treating reating Implant Patients

1. Hav Havee an acc acceptable eptable patie patient. nt. 2. Implant made of biocompatible material. 3. Be durable. 4. Have proper surface qual quality ity. . 5. Have Have acc acceptable eptable socket created in bone. 6. Ha Have ve surgical procedure properly done. 7. Have Have healin healing g completed with acceptable bone interface. 8. Have healing period without pathological stress. 9. Have normal implant function functio n without pathological stress.

 

Indications Indicati ons for Implant Therapy 

 A. The edentulous patient: • Edentulous mandible • Edentulous maxilla. B. The partially-edentulous patient: • Free end edentulous situation • Multiple missing teeth. C. Single tooth loss.

 

 Absolute Contr  Absolute Contraindications aindications for Implant Treatment 1. Uncontrolled-diabetes mellitus. 2. Long-term L ong-term immun immunosuppressant osuppressant drug therapy therapy.. 3. Diseases of connectiv connectivee tissue. 4. Blood dyscr dyscrasias asias and ccoagulopathies oagulopathies..

5. Regional malignancy. 6. Metastatic disease. 7. Previous Previ ous radiation to the jaws that might lead to postsurgical osteoradionecrosis. 8. Alcohol or drug addiction. 9. Severe psychologic psychologic disorders disorders..

 

Intraoral Contraindications This includes: 1. Unfavor Unfavorable able inter interarch arch relation relationships. ships. 2. Problematic occlusal occlusal and functional relationsh relationships. ips. 3. Pathologic Pathol ogic considerations considerations iin n alveolar bone, example, fibro-osseous f ibro-osseous disease. disease. 4. Pathologic Pathol ogic alteration of the oral mucosa, example, cysts, infections.

5. Xerostomia. 6. Macroglossia. 7. Unres Unrestor tored ed teet teeth h—poor oral hygiene.

 

Radiographs Radiographs used in dental implants are panoramic radiographs. How However ever,, this t his technique has has certain inhe inherent rent problems that that have to to be taken into consideration like l ike distortion of spatial relationships. In order to eliminate thedistortion problems panoramic panoramic radiographs radiographs and their

use templates with incorporated metal spheres have beenofdemonstrated. Other Radiographic Procedures Employed These are: 1. Periapical Periapical dental dental radiograph radiographs. s. 2. Rast-O-Pan bite blocks. 3. Lateral Lateral cephalomet cephalometric ric radiogr radiograph. aph. 4. Occlusa Occlusall radiogr radiograph. aph. 5. Tomography  6.Computed tomography 

 

Surgical Procedures

Moststage threaded threaded endosseous endosseo either in one (or) two stages.us implants can be placed either One-stage: Endosseous Implant Surgery  Surgery  In this procedure the coronal coronal portion stays exposed through gingiva during the healing period. For For example, ITI system, TG Implant I mplant of 3i system and Life core single – stage system. One stage stage endosseous endosseous implant surgery: surgery: In this implant surgery, the implant (or) healing abutment protrudes about 2 to 3 mm from the bone crest and the flaps are adapted around the implant. In posterior areas of the mouth the flap f lap is thinned and sometimes placed placed apically to increase the zone of keratinized attached gingiva.

 

Surgical Technique echniq ue Flap design and incisons: The flap f lap design design is always always a crestal incision bisecting bisecting the existing existi ng keratinize keratinized d tissue. The soft tissue is not thinned in anterior or other esthetic areas of the mouth to prevent the metal collar collar fr from om showing, showing, full- thickness flaps f laps are

elevated buccally buc lingually. lingually . implant Placement ofcally theand implant: The implant site preparation to place implants in one stage surgery is identical to principles of two-stage except, implants or healing abutment is placed in i n such a way that head of implant protrudes about 2 to 3 mm from the bone crest. Closure of the flap: f lap: The keratinized edges of the flap are tied with independent sutures around the implant, when keratinized tissue is abundant, scalloping around the implant provides provides better flap f lap adaptation.

 

Surgical steps in implant placement. (A) Initial incision placed (B) Reflection Ref lection of f lap (C) Osteot Osteotomy omy proce procedure dure at implant site (D (D)) Checking for parallelism of implant (E) Placement of implant (F) Repositioning Reposit ioning of f lap and place placement ment of sutures

 

 Advantages  Advantag es and disadv disadvantag antages es of one stage implant surgery.  Advantag  Adv antages: es: a. Mucogingival Mucogingival manag management ement around the implant is easier.

Patient comfort comfort increases b because ecause less less surgeries areb.involved. c. Esthetic Est hetic management is easier in many cases. Disadvantage: If extensive extensive bone loss occurs at the implant site.  Vertical  V ertical bone augmentation is nec necessary essary,, aand nd or or bone quality is poor p oor then two-stage surgical approach iiss recommended.

 

Two-stage: wo-stage: Endosseous Implant Surg Surgery  ery  In the two-stage implant surgical approach, the first stage

ends by suturing t he soft tissues over over the remains excludedthe from the oral cavity cavity. . implant so that it In the mandible, the implants are left undisturbed for 2 to 3 months, whereas in the maxilla, maxilla, they remain covered covered for approximately 4 to 6 months because of slow sl ower er healing healin g due to less dense bone. During this period, the healing bone makes direct contact contact with the implant surface surface (osseointegration) and sometimes grows to its occlusal surface, even covering covering it it.. In second-stage surgery, surgery, the buried implant is uncovered uncovered and a titanium titanium abutment iiss connected connected to allow access to the implant implant from f rom the oral cavity. cavity. The restorative dentist then proceeds proceeds with the the prosthodontic prosthodontic aspects of the implant therapy.

 

HEALING FOLLOWING IMPLANT SURGERY 

Ifnarrow, the space between an implant and its to osseous bed is bone formation is comparable primary healing after a bone fracture, because because no callus is formed. Direct bridgin bridging g via lamellar lamel lar bone oc occurs, curs, at a rate of about about 1 m/day. m/day. Healing of implants with a wide space space ar around ound the them m is comparable to secondary healing heal ing of a bone fracture, as bone formation occurs via formation of a fibrous and bony callus, at about 50 to 100 μm/day /day.. The temporal sequence sequen ce is w woven oven bone with subsequent remodeling into lamellar bone.

 

During preparation of the implant bed, periosteal intrac intr acorti ortical cal and endos endostea teall blood blood ves vessels sels aare re damag damaged. ed.  As a result blood acc accumulates umulates in peri-implant space,  with a loose loose attachment attachment of fibrin on the surfaces of both bone and implant. This hematoma will be remodeled by proliferating tissue with new capillaries and fib fibrous rous ccollagen ollagen connective tissue in 7 to 14 days. New bone formation formation can oc occur cur directly in the vicinity of the implant depending upon the degree of its stability. Implant instability influences cell differentiation differentiati on and therefore also bone formation. S So o the implant stability stability is an absolute rrequiremen equirementt for all types of implants with adequate blo blood od supply supply..

 

Bony remodeli remodeling ng of the callus is completed after 4 to 6  weeks,, thorough  weeks thorough activa activation tion of the Hav Haversian ersian system, numerous resorption resorption canals are fformed, ormed, and the remodeling process into lamellar bone begins. These mineralization processes, which transforms the osteoid into calcified osseous substance, proceed proceed at aboutt 1 m abou microme icrometer ter per day day..

 

Different Phases of Healing Osseous Healing—Early Phase Preceded by hemorrhage and formation of a blood clot, this coagulum consists of fibrin and embedded blood cells and represents the th e scaffold for reparative

(granulation) (granulati on) tiss tissue, ue, the coagulum begins to organize  with ingrowth ingrowth of capillar capillaries ies and pr pre-ost e-osteoblasts eoblasts (centripetal bone growth). During this early stage, in addition addition to new bone formation, the macrophages as well well multin multinucleated giant cells appear and recognizes theasimplant implan t ucleated as foreign body. body. As b bone one formation iiss initiated init iated at the implant surface, the number of multinucleated giant cells are reduced.

 

Osseous Healing—Late Stage

Dependin Depending g uponand thethe width of thebed, gapdirect between theof implant surface osseous filling the space can occur occur about 0.2 mm m m by means of concentric bony apposition.  Wider spaces spaces will usuall usuallyy be filled within 14 day dayss b byy a network of new woven woven bone, which will be remodeled in about 2 months into into lamellar bone: remnants of the early woven bone may persist centrally. Direct bony contact with implant surface surf ace rranges anges from 56 to 85 percent perc ent w with ith scr screwew- type impla implants nts aand nd 46 to 82 percent perc ent with link linkow ow blade implants implants.. Areas of the implant surface not covered covered with bone will manifest adipose cells without an intervening intervening fibrous fibrous layer layer..

 

PERI-IMPLANT COMPLICATIONS Despite the long-term predictability of osseointegrated osseointegr ated implants, biologic, biomechanical, biomechanical, and esthetic est hetic complications can occur in a small percentage of cases. cases.

 

PERI-IMPLANT DISEASES Pathologic alterations in the t he tissues that contact a dental implant can be placed in the above category. Types of Peri-implant Diseases 1. Peri-implant mucositis: Inflammator Inf lammatoryy changes, which

are confined confine d to soft tissue surrounding an implant implant is termed as peri-implant mucositis. 2. Peri-imp Peri-implantit lantitis: is: It is a progressive peri-implant peri-i mplant bone loss in conjunction with soft tissue inflammatory lesion. Peri-implantitis begins at the coronal Peri-implantitis coronal portion of of the implant, while the more apical portion of implant remains osseointegrated. This means that the implant is not clinically-mobile until late stages when bone loss had progressed to inv involve olve the complete complete imp implant lant surface.

 

Clinical Features • Color changes, bleeding upon gentle probing. • Pocket formation and radiographic bone destruction. • Suppuration, Su ppuration, calculus build-up and swelling. • Mobility has been extensively described to detect early and late failures. Diagnosis  A number of clinical parameters parameters used to evaluate periodontal conditions conditions have also been us used ed to assess peri-implant peri-impla nt conditions. conditions. These parameters inclu include de evaluation of oral hygiene, peri-implant marginal tissues, and bone implant interface.

 

Probing  A successful successful implant generally generally allows probe penetration of

approximately 4 mm and theabout location of apical peri-implant bone level can be b3 etoexpected to be 1 mm to the position of the probe tip. Radiographs Reveal the bone al status as well marginal bone level. lev el.peri-implant Periapical intraor intraoral radiographs radiogr aphsas are arthe e obtained obtained instead of OPG (which have lower lower discrimination power). Direct imaging imagi ng may have the potential to replace conventional radiology. To diagnose a compromised implant implant site, soft tissue tiss ue measurements using manual or automated probes have been suggested; careful monitoring of probing depth and clinical attachment level seems useful in detecting changes of the peri-implant tissue. tissue.

 

Microbial Monitoring It is useful in evaluating the peri-implant health conditionand condit ionand microbia microbiall ccomposition omposition of a periimplan imp lantit titis is sit site. e. 

 

Management and Maintenance Management Occlus Oc clusal al ther therapy: apy: When excessive excessive forces forces are considered the main m ain etiologic factor for peri-impla peri-implant nt bone loss treatment treatment involv involves es an analy analysis sis of fit f it of the prosthesis 1.The number and position of implants. 2.Occlusal evaluation.

Change in prosthesis design, improv improvement ement of implant number, number, position and occlusal occlusal equilibratio equilibration n can contribute to arrest the progression of periimplant tissue breakdown.

 

 Anti-infective therapy:  Anti-infective therapy: The nonsurgical nonsurgical treatment treatment of perii implan per implantit titis is inv involves: olves: • Local removal of plaque deposits with plastic instruments and polishing of all accessible surface with pumice. • Subgingiv Subgingival al irrigation of all peri-implant pockets with

0.12• Systemic percent chlorhexidine antimicrobial therapy for 10 consecutive da days ys • Improv Im proved ed patient pat ient compliances with oral hygiene until a healthy peri-implant site is established. • Conventional hand and ultrasonic instruments are not suitable for the preparation and detoxification of the implant surface. • Irradiation with soft lasers for elimination of bacteria associated with with peri-implantitis has also shown promising results in the destruction of bacterial cells.

 

Surgical techniques for treatment of periimplantitis: Once the inflammatory process in the peri-implant tissue is unde underr ccontrol, ontrol, an attempt may be made to improve or re-establis re-establish h osseointegration. The surgical procedures are modifi modified ed from techniques used to tr treat eat bone defects around the teeth. Re-osseointegration: Re-osseoin tegration: It can be defined as the th e gro growth wth of

new bone bone in di direct rect contact to the previously contaminated implan implant t surface without an intervening band of organized connective tissue.

 

Maintenance

int intervention, ervention, all patients are placed on a After closesurgical recall sche recall schedule. dule. It is ad advised vised to schedule maintenance visits at least every 3 months. month s. This allows for monitoring of plaque levels, soft tissue inflammation, inf lammation, aand nd changes in the levels of bone.

 

Oral Hygiene Aids • Toothbrushes with soft, rounded bristles should be used because the surfaces of the implant implantss ar aree easily damaged. • Toothpa Toothpaste ste should be only minima minimally  lly -abrasive; -abrasive; the tooth- cleaning proc procedures edures sh should ould be co conducted nducted by rinsing or brushing with chlorhexidine. • Gauze Gauze strips or superf superfloss loss are effectiv effectivee ffor or cleaning •interproximally. Ir rigators can also be used as adjunct Irrigators adjunctive ive aids.

 

KEY POINTS 1. A dental implant is a biologic or alloplastic biomaterial inserted into soft or hard tissues tissu es of the mouth for functional or cosmetic purposes. 2. Osseointegration Osseointegration is a direct structural and functional connection between bet ween ordered living bone and the surface of

the load carrying implant. 3. Soft tissue interface of the implant consists of mucosal tissues around around intraosseous implants which which form a tightly adherent band band consisting consisting of dense collageno collagenous us lamina propria prop ria cove covered red by stratified stratified squamous squamous kerati keratinizin nizing g epithelium. 4. Bone implant interface is the relationship between endosseous implants and bone which in invol volves ves mechanisms mechanisms like fibro-osseous integration, osseo-integration and bioactive integration.

 

5. Based on shape and form implants are classified into Endosteal, subperiosteal, transosteal, submuc submucosal osal implants and endodontic endodonti c stabilizer stabili zer.. 6. Based on surface characteristics implants are classified into titanium plasma sprayed coating, sandblastingsurface etching, laser-induced surface roughening and hydro hy droxyapatite xyapatite coating. coating. 7. Surgical procedure involves: a. One-stage endosseous endosseous implant surgery surgery.. b. Two-stage endosseous endosse ous implant surgery. surgery. 8. Healing involves two phases: a. Osseous healing—Early phase. b. Late stage. 9. Pathologic alterations in the tissues that contact a dental implant are peri-implant diseases, which are peri-implant mucositi muc ositiss and peri-implanti peri-implantitis tis

 

KNOW MORE ... - Implant Implant Failure ailure - Failures Failures in implant therapy can happen sometimes sometimes and this thi s could could be due to: a. Complications that arise during the early phase following implant insertion—Early implant failures.

b. Complications that that arise after the reconstruction of the implant—late implant failures. - Causes for for Early Implant Failures Failures 1. Improper preparation of the implant site. 2. Bacterial contamination. contamination. 3. Improper mechanical stability following implant insertion. 4. Premature loading of the implant.

 

- Causes for Late IImplant mplant Failures

 Accor cording ding proceedings proceedings ofthe thellate 3r 3rd d implant European European  W Ac  Workshop orkshop ontoP Periodont eriodontology ology ate failures could be as a result resul t of: 1. Exc Excessive essive load. 2. Infection, Infection, e.g. periimplant mucositis, mucositis, periimplantitis.

 

BIBLIOGRAPHY  

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1. Belser UC, Buser D, Hess D eett al. al. Aest Aesthetic hetic implant implant restorations in partially edentulous patients—a critical appraisal. appr aisal. Periodont Periodontology ology 2000, 1998; 17: 1132. 32. 2. Berglundh T, Lindhe J et al. Th Thee ttopogr opography aphy of the  vascular system in the periodontal periodontal and and peri-implant peri-implant tissues in the dog. dog. J Clin Perio eriodont dontol ol 1994; 4: 189. 189. 3. Berman CL. Osseointegration, complications, prevention, prev ention, ecognition, n, treatment. Dent Clin North  Am 1989; 33:rrecognitio 33: 635. 635. 4. Buser D, W Weber eber HP HP,, Donath K, et al. Soft tissue reactions to non-submerged implants. J Periodontol 1990; 61: 597.

 

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