International Journal of Periodontics & Restorative Dentistry, 02/2009

The objective of this pilot study was to assess whether mineralized collagen bone substitute (MCBS) combined with recombinant human platelet-derived growth factor-BB (0.3 mg/mL) would generate adequate viable bone in buccal wall extraction defects to accommodate implant placement. The primary outcome variable was bone quality, as measured by microcomputed tomography and histologic evaluation. This was successfully accomplished in all eight specimens obtained from seven patients. The secondary outcome variables were bone quality and quantity as observed clinically, radiographically, and by the primary stability of implants at the time of placement. Soft tissue healing was excellent, and there were no unanticipated adverse events. Robust bone formation accompanied by MCBS resorption was evident in all 4- and 6-month specimens. This was accomplished without barrier membranes.

A distance of more than 3 mm between two adjacent standard implants has been shown to preserve the interproximal bone peak, resulting in only 0.45 mm of resorption. The purpose of this study was to determine whether use of the platform- switching technique would change the bone resorption patterns between adjacent implants placed less than 3 mm apart. Radiographic studies of bone resorption around 41 pairs of implants placed less than 3 mm apart in 37 patients were carried out. Mean vertical bone resorption was 0.62 mm, and the mean horizontal component was 0.60 mm. The bone peak that extended coronally beyond an imaginary line connecting the two implant-abutment interfaces was measured, and the mean bone height preservation above this interimplant line was 0.24 mm

The aim of this paper was to describe a new surgical technique designed to preserve interdental tissue in guided tissue regeneration. This procedure was created to specifically regenerate wide intrabony defects in the esthetic zone. Fourteen subjects with an intraosseous defect in the maxillary incisor region took part in this clinical study. The defects were treated with bioresorbable membranes in combination with a bovine bone mineral graft. At baseline and at 12 months after surgery, the following clinical parameters were measured: full-mouth plaque scores, full-mouth bleeding scores, probing pocket depths, clinical attachment levels, and gingival recession. A significant gain in clinical attachment level (4.57 ± 0.65 mm) and a reduction in probing depths (5.14 ± 0.95 mm) were reported 12 months after surgery. The surgical technique allowed complete flap closure in every treated site, resulting in significant improvement of the clinical parameters; thus, it appeared especially appropriate for the treatment of wide defects in the esthetic zone.

Tapered implants have become routine for immediate implant placement after tooth extraction. It seemed extremely advantageous to use tapered implants in type 4 bone, where primary stability is difficult to achieve. The authors established a surgical implant placement protocol to be followed in areas where type 4 bone and a wide bone ridge (>= 8 mm) are present. First, preparation of the implant alveolus is done exclusively with cylindric osteotomes, rather than with conic osteotomes or drills. The final cylindric osteotome is the same diameter as the final twist drill that is typically used in conventional preparation of the implant alveolus (a technique that can be adapted for use with other tapered implants). Because of the self-tapping property of the tapered implant used and its anatomic design, this surgical technique was developed to optimize the bone compaction effect in the coronal third of the implant, improving bone density and providing better primary stability values (>= 70 ISQ, via the Osstell Mentor device). With the strong bond that is created between the implant surface and the surrounding bone using this technique, immediate loading can be predictable, even in the type 4 bone that is commonly found in the maxillary tuberosity.

Four patients with chronic advanced periodontitis participated in this study. At least one mandibular first molar had to have a hopeless periodontal and prosthetic prognosis. Clinical measurements were made, and the furcation defects were surgically exposed. A notch was placed through the calculus on both the mesial and distal roots. The furcal area was root planed with diamond-tip ultrasonic instruments. The furcations were grafted with a combination of recombinant human platelet-derived growth factor and beta tricalcium phosphate. A collagen barrier for guided tissue regeneration was used on both the facial and lingual surfaces. The flaps were coronally positioned and sutured. All patients were followed at 2-week intervals for 6 months. At 6 months, all teeth demonstrated a reduction in probing depth and a gain in clinical attachment. One tooth demonstrated a Class II furcation involvement, while through-and-through furcation involvement was still evident on the other three experimental teeth. The teeth were removed en bloc and processed for histologic evaluation. Three root surfaces demonstrated periodontal regeneration, an additional three showed new attachment, and one surface revealed junctional epithelium as measured from the base of the calculus notch. The notch area could not be identified on one surface of one specimen.

This study was designed to evaluate the effectiveness of subepithelial connective tissue graft (SCTG) and acellular dermal matrix allograft (ADMA) in root coverage procedures and to examine the effect of interdental papilla dimensions on the outcome of root coverage using a new approach. This randomized controlled clinical study included 32 gingival recession defects of at least 2 mm classified as Miller Class I or II. Clinical parameters were measured at baseline and 6, 12, and 24 weeks postsurgery. At baseline, all measured clinical parameters were statistically equivalent between the two groups. With regard to the amount of mean root coverage, no significant difference was found between ADMA (85.42%) and SCTG (69.05%) groups. However, the percentage of complete root coverage was significantly greater in the ADMA group (75.0%, versus 31.3% in the SCTG group). Significant positive correlations were found between papilla height and papilla width and mean root coverage, and papilla height of at least 5 mm was associated with complete root coverage. ADMA seems to be a good substitute for SCTG to treat shallow to moderate gingival recessions. In addition, papilla dimensions, as measured using the new method, can help predict the success of future root coverage.

This report from a prospective study discusses the status of a group of 20 single maxillary sintered porous-surfaced (SPS) dental implants after 7 to 9 years in function restored with screw-retained crowns. Twenty patients each received a single SPS implant placed in a two-stage surgical approach; 65% replaced premolar or molar teeth, while the remainder replaced anterior teeth. Patients were examined annually. Standardized radiographs were used to assess peri-implant crestal bone levels and to determine an implant success rate. Jemt Papilla Index scores were used to assess the extent of papilla reformation between each implant and its two contiguous teeth. After 7 to 9 years, 17 implants were available for assessment (one patient had died, and two patients had moved away). One implant was removed after the 9-year visit because of progressive bone loss, giving a survival rate of 92.9%. The failure of this implant was related to deficiency in initial alveolar ridge width with loss of the remaining thin buccal cortical plate. With the exception of the failed implant, no significant changes in mean annual crestal bone loss were noted from years 1 to 9, giving a similar success rate (92.9%). Jemt Papilla Index scores of 2 or 3 were assigned for the majority of papillae. SPS implants can be used effectively to replace single missing maxillary teeth.

The purpose of this clinical study was to compare the effectiveness of the supraperiosteal envelope technique as performed by three surgeons with different amounts of professional experience during a 6-month observation period. Sixtyeight gingival recessions in 35 healthy patients were selected and included in clinical recordings. They were statistically evaluated at baseline and 6 months later. First, clinical parameters (attachment level, pocket depth, recession height, recession width, and gingival keratinized tissue height) were calibrated between the three operators. Then, single or multiple gingival recessions were selected and surgical techniques were standardized by the surgeons (A, B, C). The root coverage percentages obtained by the three operators were 81% for operator A, 85% for operator B, and 89% for operator C, for an average of 85%; initial recession height values were 2.5 mm (A), 4.3 mm (B), and 4.4 mm (C). The preliminary results of this trial showed the capacity of this surgical technique to provide favorable clinical benefits irrespective of the initial dimensions of recession-type defects and irrespective of the learning curve and experience of operators.

The tunnel technique is a combined therapeutic approach that includes both surgical exposure of the impacted canine and orthodontic traction of the tooth to the center of the alveolar ridge, followed by final orthodontic alignment. A healthy periodontium at the completion of therapy is the expected outcome. The tunnel technique has been shown to be effective in the treatment of impacted maxillary canines and can be suggested for the treatment of infraosseous impacted canines in the mandible when the corresponding primary canine is still present. Through the description of clinical cases, the management of the tunnel technique is reported.