A longitudinal study comparing scaling, osseous surgery, and modified Widman procedures: results after 5 years.

BACKGROUND: Scaling and root planing, osseous surgery, and modified Widman procedures are effective methods for treating periodontal diseases. Studies have been carried out to determine if these procedures are more effective than others in reducing clinical probing depths, while maintaining clinical attachment levels. The purpose of this report is to present 5-year results from a longitudinal study comparing scaling and root planing (SRP), osseous surgery (OS), and modified Widman (MW) therapies. The study has been completed for 12 years. METHODS: Sixteen adult patients with moderate to advanced periodontal disease were treated with initial scaling and oral hygiene procedures in a private practice. Posthygiene data were used to compare changes in plaque and gingival indices, probing depth (PD), clinical attachment levels (CAL), and recession. Frequency distributions were used to compare changes at individual sites. The first published report was from baseline to one year. This follow-up report is from baseline through 5 years. RESULTS: At 5 years, there were significant decreases in gingival and plaque scores. For the 3 procedures, there were significant decreases in baseline 4 to 6 mm PD (P<0.0001); however, there were no differences between the methods. Similar findings were noted for PD initially greater than 7 mm. At 5 years, OS had the greatest number of 1 to 3 mm sites (332 sites, 73.2%), while MW had the fewest number of 4 to 6 mm PD (98 sites, 21.8%). SRP had the fewest 7 mm and greater sites (15 sites, 3.4%). At 5 years, CAL loss for 1 to 3 mm PD was statistically significant for the 3 procedures. There were slight gains in CAL for 4 to 6 mm probing depths. These gains were not significant. Similar findings were seen for CAL for probing depths greater than 7 mm. OS had the greatest number of sites losing more than 2 mm of CAL (64 sites), followed by SRP (21 sites) and MW (34 sites), respectively. CONCLUSIONS: This 5-year clinical trial demonstrates that with good patient maintenance excellent clinical results can be achieved with various methods of treatment. Within the limits of this study, SRP, OS, and MW were effective at reducing probing depths with slight changes in clinical attachment levels.

Multiple isoforms of the high molecular weight microtubule associated protein XMAP215 are expressed during development in Xenopus.

We have cloned and sequenced cDNAs encoding two isoforms of XMAP215, a high molecular weight microtubule-associated protein identified in Xenopus eggs. XMAP215 is approximately 80% identical in amino acid sequence to the product of ch-TOG, a cDNA that is over expressed in certain human tumors [Charrasse et al., 1995: Eur J Biochem 234:406-413]. Northern and Western blots demonstrated that XMAP215 is expressed throughout development, from oogenesis to tadpole. We identified two XMAP215 transcripts differing only in the presence of a 108-bp sequence encoding a 36 amino acid insert. RT-PCR revealed that the transcripts encoding these two isoforms are expressed at distinct times during development: a transcript containing the insert (encoding XMAP215(M)) is expressed during oogenesis and is present through gastrulation. The second transcript (encoding XMAP215(Z)) lacks the 108-bp insert and is expressed from gastrulation onward. In situ hybridization demonstrated that XMAP215 transcripts are localized to the ectoderm of early embryos and in the developing nervous system during later development. These results suggest that XMAP215 plays important roles in at least two phases of development: (1) regulating the assembly of MTs during the rapid cell divisions after fertilization, and (2) regulating MT assembly during the development of the nervous system.

Osteoporosis and implant failure: an exploratory case-control study.

BACKGROUND: Osteoporosis has been suggested as a risk factor for implant failure, but data supporting such a link are limited. METHODS: A case-control study was designed to evaluate the association between osteoporosis and dental implant failure. Cases (n = 49) and controls (n = 49) were selected from a private practice. The following measures were collected for each patient: 1) peripheral dual-energy x-ray absorptiometry (pDEXA) bone measurements at the distal and proximal radius and ulna; 2) classification of bone quality and quantity at the time of implant placement; and 3) questionnaire data regarding potentially confounding variables. Generalized estimating equations were used to relate the likelihood of having at least one implant failure in an individual to osteoporosis measures. RESULTS: The results suggested that there was no association between pDEXA scores at the radius and ulna and the risk for implant failure. For every 1-unit increase in bone density as measured by pDEXA t-score at proximal and distal radius and ulna, the risk for a patient to lose at least one implant changed by +14% and -6%, respectively (odds ratio, 1.14; 95% confidence interval, 0.80-1.62 and odds ratio, 0.94; 95% confidence interval, 0.71-1.23). The simple visual assessment of local bone quality had a moderately sized relationship to implant failure. Implants placed in sites with thin cortical bone increased the chance for a patient to lose at least one implant by 130% when compared to implants placed in a thick cortical layer or compact bone (odds ratio, 2.3; 95% confidence interval, 1.0-5.4). CONCLUSIONS: This exploratory study suggests that a simple visual assessment of bone quality at the site of implant placement may be more informative regarding implant failure than pDEXA bone density measures obtained at peripheral bones. In order to determine whether peripheral osteoporosis measurements have a small or moderate association with implant loss, studies with larger sample sizes will be required.

Retrospective case series analysis of the factors determining immediate implant placement.

Implant placement at the time of extraction has become an acceptable treatment option. The formation of a restorative treatment plan frequently requires the removal of questionable and hopeless teeth. This retrospective case series analysis reports the reasons for tooth removal before immediate implant placement and provides a rationale for removing questionable and hopeless teeth. Root length is also analyzed as related to tooth loss. Between September 1986 and December 1998, 460 teeth were removed from 282 patients. Reasons for removal were advanced periodontal disease, endodontic complications, nonrestorable caries, roots fractures, short roots (< 14 mm in length), root resorption, and loosened posts. Implants were placed at the time of extraction. Tallies, frequency distributions, and percentages were used to determine individual and multiple reasons for extraction. For teeth with short roots, computerized measurements were made from periapical x-rays. Advanced periodontal disease and restored endodontically treated teeth with posts were the primary reasons for tooth extraction. Dental implants replaced 305 maxillary and 155 mandibular teeth.

A prospective multicenter clinical trial comparing one- and two-stage titanium screw-shaped fixtures with one-stage plasma-sprayed solid-screw fixtures.

BACKGROUND: Brånemark fixtures were originally placed in two stages, whereas titanium plasma-sprayed (TPS) solid-screws are placed in one stage. Long-term survival rates for both types of implants are excellent. Excellent survival rates have also been reported for machined screw-shaped (MS) titanium implants placed in one stage. A small number of studies have compared different implant systems and methods of implant placement. PURPOSE: The purpose of this study is to report clinical outcomes from a prospective longitudinal, multicenter study comparing Brånemark MS fixtures (Nobel Biocare, Yorba Linda, California, USA) placed in either one or two stages with a one-stage TPS system (ITI Straumann, Waldenburg, Switzerland). METHODS: A protocol was designed to compare implant survival rates, changes in crestal bone for titanium MS fixtures placed in one and two stages, and plasma-sprayed solid-screw fixtures placed in one surgical stage. Twenty-nine patients ranging in age from 24 to 82 years received MS fixtures in one stage. The average age for males was 58 years (n = 11), whereas the ages for females (n = 18) ranged from 15 to 84 years (average 58 years). Twenty-nine patients received machined titanium fixtures placed in two stages. There were 20 females ranging in age from 23 to 74 years (average 54 years) and 9 females ranging from 24 to 74 years (average 46 years). Twenty-five patients received TPS fixtures. There were 15 males, ranging in age from 57 to 79 (average 70), and 10 females, ranging in age from 40 to 83 years (average 62 years). Bone quality and quantity were determined from radiographs and during site preparation. Patient age, sex, location of implant placement according to jaw, length of fixtures, and number of lost fixtures were entered onto computer code sheets and continuously entered into a locked computer system. For one- and two-stage MS fixtures, nonstandardized periapical radiographs were taken at abutment connection and follow-up. Solid screws were x-rayed at prostheses connection and follow-up. The average time between implant restoration and radiographic follow-up was 15 months. The x-rays were scanned into a computer, and a program designed to measure radiographs was used to determine changes in crestal bone. Measurements for one- and two-stage MS fixtures were made from the top of the implant shoulder to the first bone to implant contact mesial and distally. Plasma-sprayed screws were measured from the bottom of the implant to the coronal most bone to implant contacts mesial and distally. Mesial-distal radiographic measurements were averaged and changes were compared using the t-test for related samples. RESULTS: This report presents data from the 2- to 3-year follow-up examinations. Twenty-nine patients received 80 one-stage MS fixtures. Between 0 and 1 year, two fixtures were lost, resulting in a 97.5% cumulative survival rate (CSR). The CSR remained unchanged through the 2- to 3-year follow-up. Twenty-eight patients received 78 two-stage MS fixtures. One implant was lost prior to loading and two were lost between 0- and 1-year follow-up, yielding a 96.2% CSR at the end of 1 year. The CSR remained unchanged through the 2- to 3-year follow-up. Twenty-three patients received 78 solid-screw plasma-sprayed screws. One implant was lost prior to loading and one between the 0- to 1-year follow-up, accounting for a 97.4% CSR at the 2- to 3-year follow-up. Changes in bone crest measurements for one-stage titanium threaded fixtures were insignificant (-0.11 mm, p = .08, maxillary; 0.07 mm, p = .42, mandibular). For two-stage MS fixtures, crestal bone loss was insignificant in maxillae (-0.16 mm, p = .92) and significant in mandibles (-0.43 mm, p = .000). There was significant bone loss for TPS implants in maxillae and mandibles (maxillae, 1.31 mm, p = .04; mandibles, 0.98 mm, p = .000). CONCLUSIONS: Cumulative survival rates for MS fixtures placed in one and two stages as well as one-stage TPS screws up to the 2- to 3-year follow-up examination were similar, indicating excellent clinical results. Radiographic measurements for changes in crestal bone loss were clinically insignificant for fixtures placed in one stage. For two-stage fixtures, maxillary changes were insignificant, whereas mandibular bone loss was statistically significant but clinically insignificant. Changes in crestal bone loss for TPS implants were statistically significant.

Model Spinal Cord Injury System trends, and implications for the future.

In the 25 years since the federally designated Model Spinal Cord Injury Systems program was started, many changes have occurred. The systems have increased in number and location and have changed in composition. Data are available on approximately 19,000 acutely injured traumatic spinal cord injured individuals, with more than 117,000 total records. This volume of data allows analysis of many trends affecting the care of people with spinal cord injuries. The time span covered by the database allows comparison of various time periods, including the most recent decade--during which managed care has emerged as a dominant force in health care evolution. This article summarizes these trends, based on information in the articles in this special issue devoted to the Model Spinal Cord Injury Systems. Finally, this article offers an analysis of future implications for SCI care in general and the federally designated Model Spinal Cord Injury Systems program in particular.

Long-term evaluation of 282 implants in maxillary and mandibular molar positions: a prospective study.

BACKGROUND: Placement of implants into molar positions presents diagnostic, surgical and prosthetic challenges. There are few reported studies for implants placed into molar positions. The purpose of this prospective longitudinal study is to report long-term clinical outcomes for 282 implants placed into molar positions. METHODS: Two-hundred-twelve patients received 282 implants. Implant size, location, jaw shape, and bone quality were recorded for all implants placed into molar positions. Seventy implants were inserted in maxillae and 212 in mandibles. Marginal bone level changes in maxillae and mandibles were measured from non-standardized periapical radiographs taken at abutment connection and an average follow-up of 3.9 years. Mesial-distal implant measurements were made from the top of the implant cylinder to the first point of bone to implant contact. In mandibles, 39 implants were used for single molar replacements, 67 implants were placed into excellent bone quality (type I) and 113 were in good bone quality (type 11); 145 implants were placed into bone with moderate bone resorption (type B); 166 implants were placed in first molar positions and 46 in second molar sites. RESULTS: At 6 years the cumulative success rate (CSR) for mandibular implants is 91.5%, and the success rate from the 2 to 3 year follow-up is 100%. Of the 70 implants placed in maxillae, 16 replaced single molars. Thirty-two implants were placed in jaw shape B with type 2-bone quality. For maxillary implants, the 6-year CSR was 82.9% and the success rate remained steady at 100% after the 2 to 3 year follow-up. For maxillary implants, at abutment connection the average marginal bone level was 1.67 mm, while at follow-up it was 1.98 mm. These differences were statistically significant (P = 0.04), but are not considered to be clinically significant. For mandibular implants, at abutment connection the mean marginal bone level as measured from radiographs was 2.11 mm, and at follow-up was 2.02 mm. This slight gain in bone level was not statistically significant and is not considered to be clinically significant. CONCLUSIONS: Results of this prospective longitudinal study of implants placed into molar positions indicates favorable clinical outcomes. These CSR rates (91.5% mandibles, 82.9% maxillae) are less than what has been reported for implants placed into mandibular and maxillary anterior segments. Differences in outcomes between anterior and posterior locations may be related to bone quality and quantity.

Formation of bone around titanium implants placed into zero wall defects: pilot project using reinforced e-PTFE membrane and autogenous bone grafts.

BACKGROUND: Guided bone regeneration (GBR) frequently is used to augment implants with various types of bone defects. The defects often are grafted with different materials, yet there is insufficient evidence that these materials enhance bone-to-implant contacts. PURPOSE: The purpose of this pilot project was to test the principle of GBR to promote bone formation adjacent to commercially pure titanium implants placed within zero-wall defects. Histologic and histomorphometric measurements were used to evaluate new bone formation. MATERIALS AND METHODS: Under appropriate anesthesia, deep, wide defects were created within the mandibles of two large dogs. Buccolingual bone was removed to the depth of the defects leaving only the mesial and distal walls. Of the eight implants placed, three were augmented with titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) barriers and autogenous bone chips. Three sites were augmented with barrier membranes only, and two sites were not augmented or grafted and served as controls. Seven months after surgery the dogs were sacrificed and block sections were taken for histologic evaluation. RESULTS: Histologic and histomorphometric measurements were used to evaluate new bone formation. Results from this evaluation revealed bone formation at the membrane-only sites and the membrane-plus-bone grafted sites. The bone grafts were completely incorporated by the newly formed marginal compact bone. For all treated sites, there was poor bone-to-implant contact. Histomorphometric measurements showed a trend toward greater bone formation at membrane-treated sites compared with control sites. However, autogenous bone grafting did not seem to affect the amount of newly regenerated bone. CONCLUSIONS: Within the limits of this pilot project, findings show trends toward bone healing, indicating constant and enhanced bone regeneration over the exposed implant. Bone contact to the implant surface generally was poor.

Five-year evaluation of implants placed at extraction and with dehiscences and fenestration defects augmented with ePTFE membranes: results from a prospective multicenter study.

BACKGROUND: Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations. Membranes also have been used to protect defects adjacent to implants placed at the time of extraction. The concept of guided bone regeneration relates to preferentially allowing cells from bone to migrate into various defects while excluding fibrous tissue and epithelium. The purpose of these procedures is to enhance bone-to-implant contact at the treated sites and to prevent mucosal complications. PURPOSE: The purpose of this article is to report clinical outcomes for implants placed at the time of extraction and augmented with expanded polytetrafluoroethylene (ePTFE) and followed for 5 years. The outcomes for implants with dehiscences and fenestrations augmented with ePTFE barriers and followed up to 5 years also are reported. METHODS AND MATERIALS: Four treatment centers participated in this study (Tucson, Gothenburg, Spokane, and Leuven). In the extraction group, teeth were removed for varying reasons, and Brånemark implants were placed and stabilized within the host bone. Defects present at the coronal implant aspect were covered with ePTFE barrier membranes. Flaps were rotated to cover the membrane-treated sites. If exposure of the material occurred prior to second-stage surgery, the membranes were removed. Barriers remaining unexposed were removed at second-stage surgery. The implants were followed up to 5 years. In the fenestration and dehiscence group, implants with exposed threads were augmented with ePTFE barrier membranes. The barriers were removed at appropriate intervals, and the patients were followed up to 5 years. Radiographic measurements were made from nonstandardized periapical radiographs at abutment connection and 1, 3, and 5-year follow-up visits. RESULTS: Forty patients participated in the extraction group. They received a total of 49 implants. Three implants failed prior to loading. The 5-year cumulative survival rates for implants placed at the time of extraction were 93.9% and 93.8%, respectively, for maxillary and mandibular implants. The average maxillary mesial and distal marginal bone loss (1-5 yr) was 0.3 mm (standard deviation [SD] = 1.5) and 0.3 mm (SD = 1.0). In mandibles, the average mesial and distal bone loss (1-5 yr) was -0.2 mm (SD = 0.5) and -0.05 mm (SD = 0.6), respectively. The dehiscence and fenestration group included 44 patients. Twenty-six were followed for up to 5 years. Eight patients experienced total implant failure. For dehiscences and fenestrations, the cumulative survival rates were 76.8% and 83.8% for maxillary and mandibular implants, respectively. The average maxillary mesial and distal bone loss (1-5 yr) was 0.4 mm (SD = 0.8) and 0.2 mm (SD = 0.9), respectively. In mandibles, the average mesial and distal marginal bone loss was 0.3 mm (SD = 0.9) and 0.3 mm (SD = 0.8), respectively. CONCLUSIONS: Implants placed at the time of extraction and augmented with ePTFE barrier membranes have favorable long-term predictability. On the other hand, long-term evaluation of implant dehiscences and fenestrations augmented with barrier membranes indicates that they have less favorable 5-year survival rates. Membrane augmentation of these may be questioned.

A prospective clinical trial of endosseous screw-shaped implants placed at the time of tooth extraction without augmentation.

This prospective clinical trial evaluated 134 implants in 81 patients. The implants were placed at the time of tooth extraction and were not augmented with barrier membranes or graft materials. The implants were placed into good jaw bone anatomy and quality and were restored by dentists familiar with the implant system. Forty-seven implants were followed between 4 to 5 years with a cumulative success rate of 93.3%. Marginal bone levels were measured for 61 patients with 108 implants. The average mesial-distal measurements for maxillary implants at abutment connection were 1.02 mm (SD+/-0.59) and 1.36 mm (SD+/-0.78) at an average of 32 months follow-up. These differences were not significant. The average mandibular mesial-distal measurements at abutment connection were 1.05 mm (SD+/-0.92) and 1.54 mm (SD+/-0.91) at follow-up. These differences were statistically significant (P = 0.0027). Removal of one patient (5 implants) with advanced marginal bone loss from the data provided a marginal bone level of 1.20 mm (SD+/-0.94) at abutment connection and 1.30 mm (SD+/-0.87) at follow-up. These differences were not significant. The results of this study indicate that implants placed at the time of extraction without augmentation or grafting have excellent long-term cumulative success rates.

Histologic findings after implantation and evaluation of different grafting materials and titanium micro screws into extraction sockets: case reports.

The purpose of this study was to compare extraction socket healing in 8 patients after implantation with either xenogenic bovine bone (n=5 sites), demineralized freeze-dried bone (DFDBA) (n=3 sites), autologous bone (n=3 sites), or human bone morphogenetic proteins in an osteocalcein/osteonectin carrier (hBMP/NCP) (n=2 sites). Three of the patients received 6 commercially pure micro screws which were fixed into extraction sockets, after which the sockets were implanted with either bovine bone (n=3 sites), DFDBA (n=2 sites) or intraoral autologous bone (n=1 site). Biopsies of the extraction sockets were taken from 3 to 6 months after treatment (average, 4.6 months). For comparison of healing between the implanted materials, histologic evaluation and bone scores were determined. Bone scores of 0 indicated an absence of new bone, with dead implanted bone particles entrapped within connective tissue, while a score of 3 indicated the entire field consisted of vital bone. Biopsies from bovine bone sockets revealed dead implanted particles surrounded by connective tissue. Isolated sections showed host bone in contact with the bovine bone particles. Bone scores ranged from 0 to 3. Biopsies from DFDBA-implanted sites revealed dead particles entrapped with dense connective tissue. The bone scores ranged from 0 to 1. Biopsies from sites implanted with hBMP/NCP revealed a combination of woven and lamellar bone with bone scores of 3. Five of the 6 micro screws were processed and evaluated. One screw was mobile at the time of removal and was not evaluated. Bone scores were used to compare new bone formation adjacent to the micro screws. Bone scores ranged from 0 to 2. A score of 0 indicated non-vital implant material in contact with host bone and connective tissue in contact with implant; 2 indicated vital bone in contact with the majority of the implant surface. Retrieved sockets with micro screws implanted with bovine bone (n=2) demonstrated a connective tissue interface between the screws and the surrounding tissues (bone score 0). The adjacent tissues showed dead bovine particles entrapped within fibrous tissue. Retrieved screws implanted with DFDBA (n=2) were surrounded by connective tissue, with dead bone particles enmeshed within fibrous tissue (bone score 0). The screw implanted with intra-oral autologous bone was primarily surrounded by vital bone with a connective tissue interface (bone score 1). Three implant threads were in contact with bone. The results of this study indicate that bovine bone, DFDBA, and intraoral autologous bone do not promote extraction socket healing. Sockets implanted with hBMP/NCP contained vital woven and lamellar bone. Xenogenic bovine bone and DFDBA did not contribute to bone to micro screw contacts and are not recommended for enhancement of vital bone to implant contacts. Intraoral autogenous bone also does not appear to significantly contribute to bone to implant contacts. Intraoral autologous bone, xenogenic bone, and DFDBA appear to interfere with normal extraction socket healing.

Crown lengthening: the periodontal-restorative connection.

Crown lengthening procedures are based on biologic principles that can be determinants for successful treatment. These procedures are fixed on an understanding of the biologic width. A few of the indications for crown lengthening are caries beneath the gingival margin, fractured teeth with insufficient clinical crown exposure, and teeth with excessive occlusal or incisal wear. This article describes flap designs, the use of a new bur probe for precise measurement of clinical crown exposure, and suturing methods for flap stabilization. Clinical documentation of patients with various clinical situations requiring crown lengthening is presented.

Alveolar bone anatomic profiles as measured from dry skulls. Clinical ramifications.

The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 111 dry skulls were evaluated at Baylor College of Dentistry (Dallas, Texas). The skulls were arbitrarily divided into flat, scalloped and pronounced scalloped anatomic profiles according to alveolar bone anatomy. The number of buccal dehiscences and fenestrations was determined for each skull according to their anatomic morphotype. 10 skulls from each group were selected for bone height measurements. The measurements were made with a periodontal probe and ruler from the height of the interproximal bone to the buccal alveolar crest. Kodachrome slides were used to measure mesial-distal tooth width and length from ten skulls from each anatomic category. The average number of fenestrations for each group was 3.5. The mean number of dehiscences for flat and scalloped skulls was 0.5. The average number of dehiscences for pronounced scalloped was 1.2. There were no significant differences when the groups were compared. The mean distance from the height of the interdental bone to the alveolar crest was statistically significant when the groups were compared (flat 2.1 mm, scalloped 2.8 mm, pronounced 4.1 mm) (Tukey, p = 0.05). There were no significant differences when tooth shapes were compared with bone anatomy. Pronounced scalloped anatomic profiles were slightly narrower when compared with the other groups. The observations reported have treatment ramifications when patients with scalloped or pronounced scalloped morphotypes are being considered for dental implant placement.

One-step surgical placement of Brånemark implants: a prospective multicenter clinical study.

This prospective longitudinal multicenter study evaluated the clinical outcomes after placement and restoration of one-step Brånemark implants into the maxillae and mandibles of completely and partially edentulous patients. Six surgical treatment centers participated in this study, in which 135 implants were placed into 63 adult patients. All implants were stable after placement. The majority of implants were placed into type B bone with minimal jaw resorption and type 2 bone quality. After implant placement, standard transmucosal healing abutments were firmly placed. The average amount of time between implant placement and prosthetic abutment connection was 170 days in the maxillae and 147 days in the mandibles. To evaluate crestal bone changes caused by implant placement, a periodontal probe was used to measure midbuccally from the top of the implant cylinder to the alveolar crest; in 29 patients, 54 midbuccal bone crest sites were remeasured following prosthetic abutment connection. Crestal bone changes in mandibles and maxillae were statistically and clinically insignificant. Six implants were lost prior to loading and one implant has not been restored. No implants or restorations were lost after loading. At 1 year, the implant success rate was 95.6%. Mesiodistal radiographic measurements from 34 patients were averaged, and changes from prosthetic abutment connection to, on average, 12 months follow-up were compared. The radiographs, which were digitalized, measured from the bottom of the implant cylinder to the most coronal bone in contact with implant thread. For mandibular implants, the mean radiographic bone level at prosthetic abutment connection was 1.07 mm; after loading, it was 1.35 mm. For maxillary implants, the mean radiographic bone height at prosthetic abutment connection was 1.16 mm; after loading, it was 1.36 mm. These changes were not statistically significant. The 1-year outcomes from this patient series indicate that one-step Brånemark implants provide excellent clinical results when placed in patients with good bone quality and quantity.

Clinical and histologic observations of sites implanted with intraoral autologous bone grafts or allografts. 15 human case reports.

The cases reported in this paper were treated at 7 different clinical centers and present clinical and histologic observations from 15 patients and 21 human biopsies. The biopsies were taken from extraction sockets or dental implant sites which were grafted with either autologous intra-oral bone (6 sites), demineralized freeze-dried bone (DFDBA) (7 sites), or mineralized freeze-dried bone (MFDBA) (7 sites), or a combination of autologous bone, DFDBA and a barrier membrane (1 site). Six sites were grafted with DFDBA and augmented with expanded polytetrafluoroethylene (ePTFE) barrier membranes. Biopsies for histological evaluation were taken 4 to 13 months after implantation. A bone scoring system of 0 to 4 was used to evaluate the sections for dead implanted particles or the presence of vital bone. A bone score of 3 indicated the presence of dead implant material, blood vessels, islands of cartilage, osteoblasts, and new bone formation. A score of 4 indicated total replacement of the implanted material by the host bone. The average bone score for sites which received autologous bone was 2.33; for DFDBA sites, 0.98; and MFDBA was 0.18. The over-riding histologic characteristic of sites implanted with DFDBA or MFDBA was retention of non-vital graft particles within fibrous connective tissue. Biopsies taken adjacent to the host bed demonstrated incorporation of the allografts (osteoconduction). Sites grafted with autologous bone chips also demonstrated non-vital bone chips surrounded by vital host bone (osteoconduction). Sites which received barrier membranes did not appear to improve or impair bone healing of the augmented sites. Autologous bone chips harvested from within the oral cavity as well as allografts may serve as biologic fillers, but do not apparently contribute to osteoinduction. Autologous bone will eventually be resorbed and replaced by the host. DFDBA and MFDBA are resorbed very slowly and apparently do not contribute to osteoinduction. Allografts apparently are not resorbed by osteoclasts and therefore their continued use around dental implants is questioned.

A prospective multi-center study evaluating periodontal regeneration for Class II furcation invasions and intrabony defects after treatment with a bioabsorbable barrier membrane: 1-year results.

The purpose of this prospective multi-center study was to evaluate a resorbable barrier membrane designed for periodontal regeneration. Thirty-one Class II furcations and 30 two- and three-wall intrabony defects were treated by flap debridement and bioabsorbable barrier membrane augmentation. The efficacy of treatment was evaluated in terms of changes in vertical probing depth (PD), horizontal probing depth (HPD), clinical attachment levels (CAL), and recession. Five centers participated in the study. Changes in clinical parameters are reported by individual center and by the average of the centers. All patients had either one molar with a Class II furcation or an intrabony defect. Baseline data were taken on the day of surgery. Post-treatment data were collected at 6 months and 1 year. This report is based on the 1-year findings. The average initial PD for Class II furcations was 6.1 mm. At 1 year the average PD was reduced to 3.6 mm, a 2.5 mm change. These differences were clinically and statistically significant (P < 0.0001). There was an average gain of 2.1 mm of clinical attachment (P < 0.0001) and 0.4 mm of recession (P < 0.04). There was a mean of 1.8 mm change in HPD (P < 0.0001). For intrabony defects, at 1 year there was an average PD reduction of 4.1 mm (P < 0.0001) and a mean gain of CAL of 2.9 mm (P < 0.0001). At 1 year the average recession was 0.9 mm which was statistically significant. When treatment outcomes were compared between centers there were no differences for either group of treated defects. There were differences between centers when baseline PD for furcations and intrabony sites were compared. The results of this study indicate that clinically and statistically significant improvements in PD, CAL, and HPD occurred after treatment of Class II furcations and 2- to 3-wall intrabony defects with the bioabsorbable periodontal membrane.

Flap designs for minimization of recession adjacent to maxillary anterior implant sites: a clinical study.

The purpose of this study is to present new flap designs for the prevention of postoperative gingival recession adjacent to maxillary anterior sites that received dental implants. Nine patients received 10 implants in the maxillary anterior region. Gingival morphotypes and smile lines were evaluated prior to implant placement. Gingival probing depths, clinical attachment levels, and recession were recorded at teeth adjacent to implant sites at the initial exam and 3 months after implant restoration. A minimum of 5 mm of crestal bone width was required for implant placement. The labial flaps for healed ridges and implants placed into sockets were extended to or within 1 to 3 mm beyond the alveolar crest. In two sites, transfer of the implant relationships was made to provide the patients with provisional restorations at the time of second-stage surgery. Four patients had implants placed at the time of tooth removal. In these patients, expanded polytetrafluoroethylene barrier membranes were modified, removing the outer rim of material. The inner portion of the material was placed over the implant and the flaps were sutured, leaving the center part of the material exposed. The purpose of using the barrier in this manner was to protect the clot and subsequent granulation tissue formation during the first 2 weeks of healing. The material was removed 2 weeks after surgery. Six implants were placed into edentulous sites. At second stage surgery, flaps were reflected to the alveolar crest, thereby minimizing the potential for gingival recession. Provisional restorations placed at the time of implant uncovering appeared to support the repositioned gingiva. Changes in probing depth, clinical attachment levels, and recession were not statistically or clinically significant. Results of this pilot project suggest that flap designs minimized recession at teeth next to implant sites.