Single Tooth Replacement Treatment Options PDF

SINGLE TOOTH REPLACEMENT TREATMENT OPTIONS 1  POSTERIOR SINGLE-TOOTH REPLACEMENT OPTIONS 1. Removable partial denture (RPD) 2. Resin-bonded prosthesis 3. Space maintainer 4. Fixed partial denture (FPD) 5. Implant prosthesis...

SINGLE TOOTH REPLACEMENT TREATMENT OPTIONS 1  POSTERIOR SINGLE-TOOTH REPLACEMENT OPTIONS 1. Removable partial denture (RPD) 2. Resin-bonded prosthesis 3. Space maintainer 4. Fixed partial denture (FPD) 5. Implant prosthesis 2 REMOVABLE PARTIAL DENTURE (RPD) 1. Hygiene 2. Soft tissue replacement in esthetic areas 3. Maxillary lip support in gross defects 4. Minimum tooth preparation 5. Reduced cost NO REPORTED ADVANTAGES EXIST FOR AN RPD REPLACING ONE POSTERIOR TOOTH 3  DISADVANTAGES OF SINGLE-TOOTH REMOVABLE PARTIAL DENTURES 1. Bulk and the need of cross arch stabilization 2. Food debris, plaque 3. Movement ( Speech - Function ) 4. No clinical studies 5. Bone loss 6. Highest loss of abutment teeth (up to 44% within 10 years) Shugars et al and Aquilino et al have reported survival rates of teeth adjacent to treated ranges from 17% to 44% abutment tooth loss at 4.2 to 13.5 years 4 RESIN-BONDED FIXED PARTIAL DENTURE The primary advantages of this restoration are the minimal preparation of the adjacent teeth and reduced cost. Failure rate at least 30% within 10 years and as high as 54% within 11 months. The highest survival rates occur in the maxillary anterior, followed by mandibular anterior, maxillary posterior, and mandibular posterior teeth respectively. 5  MAINTENANCE OF THE POSTERIOR SPACE A third treatment option to restore missing posterior teeth is to not replace the tooth but instead to maintain the missing space The location of a missing posterior tooth often influences the prosthodontic treatment plan. In general, when third molars are missing, the author suggests not replacing a second mandibular molar 6  FIXED PARTIAL DENTURE The treatment most commonly used for the replacement of a posterior single tooth is the three-unit fixed restoration but it presents survival limitations to the restoration and to the abutment teeth. In an evaluation of 42 reports since 1970, Creugers et al calculated a 74% survival rate for FPDs for 15 years. Scurria et al performed a meta analysis of several reports at 10 to 15 years and found 30% to 50% failure within these time frames. 7  ADVANTAGES OF FIXED PARTIAL DENTURES 1. Most common treatment (doctor friendly) 2. Time (two appointments, 1 to 2 weeks apart) 3. Restores function, esthetics, and intraarch health 4. Few bone and soft tissue considerations 5. Proven long-term survival 6. Cost—dental insurance covers procedure (reduced patient cost) 7. Less than 6-mm mesiodistal space 8. Potential abutments have clinical mobility; will benefit from being splinted 9. Increases patient compliance and reduces fear 10. Few consequences if failure 8 DISADVANTAGES OF FIXED PARTIAL DENTURES 1. Mean life span often 10 to 15 years 2. Caries and endodontic failure of abutment teeth most common complication 3. Increased plaque retention of pontic increases caries and periodontal disease risk 4. Damage to healthy teeth 5. Failure of prosthesis related to loss of abutment teeth (8% to 18% within 10 years) 6. Fracture (porcelain, tooth) 7. Esthetics (anterior regions) 8. Uncemented restoration 9  SINGLE-TOOTH IMPLANTS From 1993 to the present time, single-tooth implants have become the most predictable method of tooth replacement. Most all 5-year reports demonstrate a higher survival rate than for any other method of tooth replacement. In 1993, Schmitt and Zarb reported that 40 implants placed in 32 patients were found in function after a period of up to 6.6 years. Many other authors reported that the survival rate was 95% and above over 5 years of service. (Ekfeldt et al, 1994 ; Cordioli et al, 1994 ; Hass et al, 1995). 10 The single-tooth implant exhibits the highest survival rates of the five treatment options presented for single- tooth replacement. In addition, the adjacent teeth have the highest survival rate and the lowest complication rate, which is a considerable advantage 11  ADVANTAGES OF SINGLE-TOOTH IMPLANTS 1. Adjacent teeth do not require splinted restorations a. Less risk of caries b. Less risk of endodontics c. Less risk of porcelain fracture d. Less risk of uncemented restoration e. Less fracture of tooth 2. Psychological need of patient addressed: patient does not desire two adjacent teeth (often virgin) prepared and splinted to restore missing tooth 3. Improved hygiene conditions a. Less decay risk b. Floss versus floss threader c. Less pontic “overhang” 12 4. Decreased cold or contact sensitivity a. Prepared teeth more temperature sensitive b. Cementum of tooth removed by tooth preparation, toothbrush or scaler sensitive 5.Improved esthetics: natural tooth versus crown esthetics 6.Maintains bone in site: 30% decreasing width within 3 years after extraction 7. Decreases adjacent tooth loss: 30% versus 0.05% risk at 10 years 13  CONTRAINDICATIONS AND LIMITATIONS OF POSTERIOR SINGLE-TOOTH IMPLANTS 14 TRANSITIONAL RESTORATIONS Could be used in esthetic regions during implant healing. Problems : - Compromise the result and volume of the augmentation - May also cause bone loss - May cause implant failure from the early loading around the implant during Stage I healing. - May depress the interdental papillae of the adjacent teeth, resulting in an esthetic compromise. Resin-bonded fixed restoration may be fabricated when replacing teeth in the esthetic zone. For non esthetic area.. no need for transitional 15 restoration IMPLANT BODY SELECTION 16 The most common problem associated with a single tooth is abutment screw loosening. Crest module and abutment connection designs that decrease forces to the abutment screw are therefore indicated. The implant body should be made of titanium alloy to reduce the risk of long-term fracture A threaded implant provides greater functional surface area than a cylinder, and a tapered implant provides less surface area than a parallel walled implant body. 17 When implant bodies are internal hex designs, the dimension of the implant in the posterior regions should be at least 4 mm or more in diameter to increase the outer body wall thickness and reduce the risk of long-term body fracture. The ideal diameter of a single-tooth implant is dependent on the mesiodistal dimension of the missing tooth and the buccolingual dimension of the implant site. Implant should be place 1.0 to 1.4 mm away from the adjacent tooth to prevent angular bone loss. The ideal implant diameter is 1.5 to 2.0 mm from an adjacent tooth and 1.5 mm from the lateral width of the ridge. 18 PREMOLAR IMPLANT REPLACEMENT The most ideal posterior tooth to replace with an implant is the first premolar in either arch. The vertical available bone is usually greater in the first premolar locations than in any other posterior tooth positions. Maxillary first premolar always require bone graft to prevent recessed emergence profile and care must be taken to evaluate the canine angulation and vertical height limitation. 19  The second premolar apices may be located over the mandibular neurovascular canal or maxillary sinus. This results in a reduced height of bone, compared with the anterior region of the jaws. As a result a shorter implant is a common consequence in this region. 20 FIRST-MOLAR IMPLANT REPLACEMENT Mesiodistal dimension usually ranges from 8 to 12 mm When one 4-mm-diameter implant is placed, this may create a 4- to 5-mm cantilever on the marginal ridges of the crown which may cause bone loss, which may complicate home care, increase abutment screw loosening, and increase abutment or implant failure 21  Sullivan reported 14% implant fracture rate for single molars fabricated on standard-diameter Nobel Biocare implants and concluded that this is not a viable treatment. When possible, a larger-diameter implant should be inserted to enhance the mechanical properties of the implant system through increased surface area, stronger resistance to component fracture, increased abutment stability, and enhanced emergence profile for the crown Langer et al also recommended the use of wide- diameter implants in bone of poor quality or for the immediate replacement of failed implants. 22  When the mesiodistal dimension is 14 mm or greater, two 4-mm-diameter implants should be considered. the two regular-size implants provide more stress reduction than just one larger-diameter implant, which in turn reduces the incidence of abutment screw loosening. In 1996, Balshi et al compared the use of one implant and two implants to replace a single molar. The 3-year cumulative success rate was 99%. 23  When the mesiodistal space is 12 to 14 mm, additional space may be gained in several ways: Enamoplasty of the adjacent teeth’s proximal contours Orthodontics The implants may not be centered in the crestal width of bone. Instead, one implant is placed buccal and the other on a diagonal toward the lingual 24 ESTHETIC MAXILLARY ANTERIOR TOOTH REPLACEMENT 25 SINGLE-TOOTH IMPLANT Maxillary single-tooth replacement is one of the most challenging restorations in dentistry. However, in light of all the advantages of single-implant longevity, bone maintenance, reduced abutment teeth complications, and increased survival of abutment teeth, single-tooth implants have become the treatment of choice. According to different studies, single-tooth implant has the highest survival rate of any prosthesis type and averaged 97%. (Malevez et al, 1996 ; Gomez-Roman et al, 1997 ; Misch et al, Wennstrom et al, 2005 ; Zarone et al, 2006, Creugers et al, Lindhe et al. Goodacre et al.) 26  More recently, a trend toward single-stage and immediate-load implants has emerged for maxillary anterior region. Kemppainen et al reported a 99% success rate using one- stage and two-stage implants. Other studies have recommended one stage and immediate load with some success in specific situations. 27  As important as implant versus prosthesis survival rates is the fact that the adjacent teeth prognosis is improved with single-tooth implants compared with any other option. Priest, Krenmair et al and Misch et al indicated that adjacent teeth next to implants have less decay, less endodontic risk, less sensitivity, less plaque retention, and less evidence of adjacent tooth loss. 28 MAXILLARY ANTERIOR SINGLE- TOOTH REPLACEMENT INFLUENCING FACTORS OF TREATMENT 1. Patient’s age 2. Esthetics 3. Adjacent tooth mobility 4. Crown height and occlusal relationship 5. Mesiodistal space at crown and bone level 6. Available bone height 7. Available bone width (buccolingual) 8. Soft tissue drape type surrounding gingival tissues 9. Transitional prosthesis 29 PATIENT’S AGE Growth and development may be affected by the implant because it may act as an ankylosed tooth. Thilander et al concluded that a fixed chronological age is not an adequate guideline because of a slight continuous eruption of the adjacent teeth after adolescence. 30 The growth of the maxilla occurs in three distinct planes: transverse (width) sagittal (length) vertical The transverse growth of the anterior maxilla is completed before adolescence The sagittal growth is the result of growth at the suture and bone apposition in the maxillary tuberosity region 31  The most variable growth of concern is the sagittal growth, because the premaxilla may advance downward and forward or primarily downward. As much as 25% of this displacement is lost as the result of resorption at the anterior =>facial bone resorption of the maxillary implants placed before completion of growth 32 In premaxilla, growth should be completed before implant placement. when cessation of growth and development is undetermined => Multiple implants should not be splinte across the midline in the adolescent. 33  Misch et al. have created four guidelines for implants placed in younger patients. The chronological age of the patient The chronological age of growth cessation : for girls from 9 to 15 years and for boys 11 to 17 years As a general rule: implant insertion in the anterior maxilla is delayed: for female patients until at least 15 years for male patients until 18 years of age. However, this guideline is too variable to be used alone => ideally, age is related to the patient's biological age 34 Endocrine changes The female patient should be able to menstruate the male patient should have body hair, voice changes Size of the the child implant patient should have greater height than their same- sex parent The size of the patient is more important than the age 35 the patient has not grown in the last 6-month period This criterion is easier to observe than cephalograms or hand-wrist films with a 2-year evaluation period. 36 CHALLENGING ESTHETICS The challenge to fabricate a natural-looking crown on an implant abutment is great. The cervical esthetics of a single-implant crown must accommodate a round-diameter implant and balance hygiene and esthetic parameters. Additional prosthetic steps and components with varied emergence profiles or customized tooth-colored abutments are often required to render the illusion of a crown on a natural abutment. The implant is often 5 mm or less in diameter and round in cross section. A natural maxillary anterior crown cervix region is 4.5 to 7.0 mm in mesiodistal cross section and is never completely round. 37 CROWN HEIGHT SPACE Patients with Angle’s Class II Division II skeletal patterns, an inadequate maxillomandibular relationship, or a severe deficiency in the vertical dimension are poor candidates for many treatment options; therefore they are contraindicated for dental implants without prior corrections. This may mean orthognathic surgery, orthodontic therapy, or both is required before any tooth replacement. 38  MESIODISTAL SPACE An adequate mesiodistal space is necessary for an esthetic outcome of an implant restoration and the interproximal soft tissue of the adjacent teeth. The smallest-diameter implant body: 3.2 mm the crest module of these two-piece implants :3.5 mm or more the mesiodistal edentulous space for a two-piece implant should be 6.5 mm or greater The average maxillary lateral incisor is 6.6 mm One-piece dental implants may be fabricated in 2.5- mm to 3.0-mm diameters to accommodate a reduced mesiodistal dimension criterion 39 BONE HEIGHT The available bone for implant insertion in esthetic regions will greatly influence: The soft tissue drape Implant size Implant position (angulation and depth) The final esthetic outcome not only the available bone volume is necessary but also the position of the osseous crest is specific The ideal midcrestal position of the edentulous site: 2 mm below the facial CEJ of the adjacent teeth 40  The interproximal bone: should be scalloped 3 mm more incisal than the midcrestal position Becker et al. Found: the range of interproximal bone height above the midfacial scallop was from less than 2.1 mm to more than 4.1 mm 2.1 mm :flat 2.8 mm : scalloped 4.1 mm :pronounced scalloped 41 The flat anatomy => square tooth shape the scalloped => ovoid tooth shape pronounced scalloped =>triangular-shaped tooth However, these relationships do not always exist When a flat interdental-to-crest dimension is found on triangular teeth => the interproximal space will usually not be filled with soft tissue because the dimension of the interproximal contact to the bone will be greater than 5 mm. when a single-tooth site has inadequate bone height at the crest and the adjacent roots also have lost bone => Orthodontic extrusion of the teeth may be considered (To grow crestal bone height on the adjacent roots,in relation to the ideal crest of the ridge) 42 FACIOPALATAL WIDTH Most of the conditions that lead to single-tooth loss result in the loss of some or all of the facial bone within the first year of tooth loss :a 25% decrease in faciopalatal within 3 years: a 30% to 40% decrease After 3 years: it almost never presents adequate available bone for the properly sized implant. 43 Because: The labial plate is very thin compared with the palatal plate Facial undercuts are often found over the roots of the teeth => The bone width loss is primarily from the facial region The amount of available bone width (faciopalatal) should be at least 2.0 mm greater than the implant diameter at implant insertion and ideally more than 3 mm greater in width 44 SOFT TISSUE DRAPE When a tooth is lost: the thin interseptal bone disappears the bone remodels in a sloping fashion from the palatal to the more apical facial bony plate the interdental papillae are often depressed The use of a soft tissue removable prosthesis often accelerates the collapse of the soft tissue and its apical migration Soft tissue manipulation to restore their proper contour is often required in conjunction with implant therapy. 45 46 TRANSITIONAL PROSTHESIS The transitional restoration for a single-tooth implant is often a removable prosthesis, which lacks stability and retention (hence the name flipper). It is strongly suggested that a resin- bonded fixed restoration be fabricated to provide improved function, especially when crestal bone regeneration is performed. 47 SPECIFIC SINGLE-TOOTH IMPLANT INDICATIONS 48 ANODONTIA The absence of one or more teeth is known as anodontia and may be complete (very rare) or partial (also called hypodontia). When acceptable conditions can be created, an anterior single-tooth implant is the treatment of choice for a congenitally missing anterior tooth. 49  The missing maxillary lateral incisor is the tooth most often replaced with a dental implant because the other orthodontic or prosthetic options are usually poor alternatives. 50 ORTHODONTIC IMPLANT SITE DEVELOPMENT In specific situations, the management of the patient in the early treatment phase may require orthodontics before the implant insertion to replace the missing tooth: Space oppening congenitally missing teeth If bone height is insufficient and bone loss is also present on the adjacent teeth when the patient has a failing tooth 51  In some cases, specifically congenitally missing teeth, the preparation of the implant site with orthodontic treatment can favorably influence the treatment outcome. Other instances, when the patient has a failing tooth, a strategy may be developed to preserve as many features of the hard and soft tissue architecture with orthodontic extraction of the tooth instead of trying to recreate the tissues after tooth loss. 52 KOKICH AND KOKICH ET AL PROPOSED THE FOLLOWING TREATMENT MODALITY: The maxillary deciduous lateral incisor is prematurely extracted. The permanent canine is encouraged to erupt in the missing lateral incisor position => the bone around the canine forms in the lateral incisor position. after the eruption of the permanent canine in the lateral position, The deciduous canine is extracted The canine is orthodontically retracted into the ideal canine position. The remaining lateral incisor bone volume is abundant and ideal for an endosteal single-tooth implant. After growth and development of the child has occurred, an implant may be inserted. 53 ROOT RESORPTION Root resorption may cause the loss of a single anterior tooth. Two major categories of root resorption: external Internal when structural failure is evident and the extraction of the tooth is eminent, two different treatment options related to the type of resorption exist. Internal root resorption: The treatment of choice is often orthodontic extraction 54  a 3-month extraction process produces sufficient movement so that the remaining root diameter in the bone is smaller than the implant diameter. after 3 months of orthodontic extrusion, no void exists around the implant at the time of extraction and implant insertion. 55 56 When external root resorption is the cause of structural failure of the tooth root, Bone, replacing the root defect No evidence of a periodontal ligament space around the defect is seen orthodontic extrusion is not possible Delaying the extraction as long as possible the remaining root segments may be cored out during the implant osteotomy procedure If the surgical defect is too large for immediate implant insertion, then the osteotomy is grafted and the implant procedure is delayed. 57 REMAINING MAXILLARY ANTERIOR TEETH The anterior implant is successful only if the final restoration it supports is fully integrated within the adjacent dentition. It is no longer sufficient to only achieve osteointegration with an implant. The implant restoration complex in the esthetic zone should be achieved in a context that respects all biological tissues. 58  To obtain an ideal result When the maxillary incisor single- tooth replacement, not only evaluate the edentulous site but also the remaining anterior teeth The adjacent teeth most often dictate its length, contour, shape, and position The patient, once fully informed of the existing discrepancies and their potential negative effect on the envisioned result, may decide to: address and correct the existing problems of the adjacent teeth simply elect to accept the compromise 59 TOOTH SIZE The two maxillary central incisors should appear symmetrical and of similar size when the missing tooth is a central incisor with a mesiodistal space less or more than the size of the corresponding central incisor: Orthodontic correction is strongly encouraged Modify the existing central incisor with a veneer to make it similar in size and shape to the missing tooth restoration lowering the mesial interproximal contact Making the two centrals more square shaped Decreases the height requirement of the papilla The shades of the two centrals are also easier to match when made at the same time in the laboratory. 60 Because the clinical crown height of an implant supported central incisor is often longer than the adjacent tooth, an esthetic crown lengthening on the natural tooth may be used to align the gingival margins a crown-lengthening procedure on the natural tooth, may be more predictable than attempting to cover the implant crown with soft tissue. 61 TOOTH SHAPE Three basic shapes of maxillary anterior teeth exist: 1. square 2. ovoid 3. Triangular The tooth shape will influence the interproximal contact and the gingival embrasure. The square tooth shape is the most favorable to obtain an ideal soft tissue drape and papillae around the crown A. The interproximal contact is more apical B. More tooth structure fills the interproximal region 62  A triangular tooth shape has A. A more incisal interproximal contact B. A steeper gingival scallop C. Farther from the interproximal bone D. A space often exists between the interproximal contact and the interdental papilla of the remaining teeth When the soft tissue fills the interproximal space of the remaining anterior teeth that have a triangular shape, the tissues may be very liable and easily vanish during the healing phases after implant surgery. 63 The tooth shape also affects the topography of the underlying hard tissues. The roots of triangular tooth shapes are positioned farther apart : Have thicker facial and interproximal bone Decrease the amount of crestal bone loss after an extraction the prognosis for an immediate implant insertion is more favorable provide the recommended 1.5 mm or more of interproximal bone from the adjacent tooth The square shaped tooth: have less interproximal bone between the roots a greater risk of crestal or interproximal bone loss with an immediate implant insertion less favorable for immediate implant insertion after extraction. 64 SOFT TISSUE DRAPE The height of the maxillary lip when smiling (high lip line) is one of me most important criterion to evaluate when observing me cervical region of the maxillary anterior teeth. Ideally: The height of the maxillary lip should rest at the junction of the free gingival margin on the facial aspect of the maxillary centrals and canine teeth => the interdental papillae are visible, but little gingival display is seen over the clinical crowns. Almost 70% of patients have this ideal smile position. A “gummy smile” displays more than 2 mm of soft tissue above the clinical maxillary crowns and is more acceptable in the female patient. 65 Under ideal conditions in the maxillary anterior region: Interproximal contact should begin in the incisal third The bone: In midfacial: 2 mm below the CEl in the interproximal region : 3 mm more incisal the CEl The soft tissue: In midfacial :3 mm above the bone at the midfacial position (1 mm above the CEl) in the interproximal region : 3 to 5 mm above the interproximal bone Therefore if the interproximal contact is within 3 to 5 mm of the interproximal bone, then the interdental papilla will most often completely fill the space 66 The higher the gingival scallop: the higher the risk for gingival loss after extraction the less likely the surgical and restorative procedures will be able to restore an ideal soft tissue contour A flatter gingival scallop: minimal tissue shrinkage more ideal outcome 67 The biotype of the gingiva is usually called thick or thin. Thicker tissue: more resistant to the shrinkage or recession more often leads to the formation of a periodontal pocket after bone loss. Thin gingival tissues: more prone to shrinkage after tooth extraction more difficult to elevate or augment after tooth loss. 68 According to Kois: predictability of the maxillary anterior single-tooth implant is ultimately determined by the patient's own presenting anatomy. Favorable conditions include: 1. when the tooth position is more coronal relative to the full gingival margin 2. square tooth shapes 3. flat scallop periodontium forms 4. thick periodontium biotypes, and 5. high (4 mm) facial osseous crest positions in relation to adjacent teeth and midcrestal 70 IMPLANT CREST MODULE DESIGN The two most common complications of anterior singletooth implant replacement: abutment screw loosening crestal bone loss Both of these conditions are in part related to the implant crest module design to decrease in abutment screw loosening: an antirotational feature 71 To decrease crestal bone loss: The crest module of an implant body should also be designed to transmit some compression and tensile forces to the crestal bone. Smooth metal on the crest module transmits shear forces to the bone => increases the crestal bone loss smooth metal collars on the implant crest module should be limited to approximately 0.5 mm 72 IMPLANT SIZE the implant body should obviously not be as wide as the natural tooth or clinical crown=>the emergence contour and interdental papillae region cannot be properly established. The ideal width of bone would allow at least 1.5 mm on the facial aspect of the implant if a vertical defect forms around the crest module, that defect would not become horizontal and change the cervical contour of the facial gingiva The faciopalatal width dimension is not as critical on the palatal aspect of the implant 1. the palatal bone is dense cortical bone and more resistant to bone loss 2. the palatal area is not within the esthetic zone 73 THANK YOU 74