International Journal of Periodontics & Restorative Dentistry, 04/2008

A consecutive series of 103 surgeries in 82 patients was studied from the normal clinical population of a periodontal specialty practice. Four different techniques were employed: free gingival grafts, free connective tissue grafts, pedicle flaps, and combined techniques. Gingival augmentation using free gingival grafts was the most predictable, with 100% of cases showing a gain of >= 3 mm. The average root coverage was 2.47 mm overall but was most predictable with a combined technique, with 93% gaining >= 2 mm. Miller Class 4 cases were most predictably treated with pedicle flaps and a combined technique. Smokers and patients with more complex sites showed less improvement. Mandibular central incisors and maxillary canines were the most commonly grafted teeth.

Distraction osteogenesis (DO) is the latest addition to the variety of alveolar ridge augmentation procedures used to increase the volume of bone prior to implant placement. Thirty DO procedures were performed in 30 patients using 17 intraosseous and 13 extraosseous devices to augment deficient alveolar ridges. Fifty-five implants placed in the distracted bone were followed for a period of 34 to 60 months after loading. Five implants failed, for a 90.9% success rate. Vertical augmentation ranged from 3.5 to 13.0 mm (average, 7.8 mm). At least one complication was encountered, requiring additional hard or soft tissue surgery, in each of the 30 reported cases. This paper reviews complications encountered in the DO-treated patients, suggesting solutions and measures to prevent these problems.

This clinical and radiographic prospective study evaluated bone loss around twopiece implants that were restored according to the platform-switching protocol. One hundred thirty-one implants were consecutively placed in 45 patients following a nonsubmerged surgical protocol. On 75 implants, a healing abutment 1 mm narrower than the implant platform was placed at the time of surgery. On the remaining implants, a healing abutment of the same diameter as the implant was inserted. All implants were positioned at the crestal level. Clinical and radiographic examinations were performed prior to surgery, at the end of surgery, 8 weeks after implant placement, at the time of provisional prosthesis insertion, at the time of definitive prosthesis insertion, and 12 months after loading. The data collected showed that vertical bone loss for the test cases varied between 0.6 mm and 1.2 mm (mean: 0.95 ± 0.32 mm), while for the control cases, bone loss was between 1.3 mm and 2.1 mm (mean: 1.67 ± 0.37 mm). These data confirm the important role of the microgap between the implant and abutment in the remodeling of the peri-implant crestal bone. Platform switching seems to reduce peri-implant crestal bone resorption and increase the long-term predictability of implant therapy.

The aim of this study was to test the color-change effect of all-ceramic restorations compared with porcelain-fused-to-metal (PFM) restorations on marginal peri-implant soft tissue. Thirty patients were randomly divided into 2 groups of 15 subjects each. The allceramic group received all-ceramic crowns on aluminum oxide-based abutments, while the PFM group received crowns on titanium or gold abutments. A reflectance spectrophotometer was used to measure the color difference (ΔEImplant) between the midfacial periimplant mucosa before and after restoration insertion. The color difference (ΔETooth-implant) between the midfacial peri-implant mucosa and the gingival margin of the corresponding neighboring tooth was tested. The mucosal thickness was measured midfacially around the implant (MTImplant) and neighboring tooth (MTTooth). ΔEImplant values were similar for the all-ceramic (7.4 ± 2.7) and PFM groups (7.6 ± 2.8). The all-ceramic group induced significantly less visible mucosal color change (3.4 ± 1.4) compared to the PFM group (5.2 ± 2.3). The MTImplant value of the all-ceramic group was 3.4 ± 0.8 mm, while that of the PFM group was 2.9 ± 0.9 mm, which was not significantly different. Significant differences were found when comparing MTImplant (3.1 ± 0.9) and MTTooth (1.2 ± 0.3) values for test and control groups. All-ceramic restorations revealed a better color match to the neighboring teeth than PFM restorations.

This case report evaluated the long-term effects of osseous resective therapy in the treatment of a patient with moderately advanced periodontal disease. In 1984, the patient underwent initial therapy followed by a periodontal surgical phase consisting of osseous recontouring with an apically positioned flap. After 20 years, in 2003, the patient presented with a traumatic complication. An exploratory surgery revealed a fracture on the roof of the pulp chamber on the maxillary left first molar. The buccal roots were resected, preserving the palatal root, and a reevaluation of the long-term outcome of osseous resective surgery was performed. It is suggested that the positive treatment result is the consequence of the reestablishment of tissue morphology favorable for oral hygiene and plaque control by the patient.

This case report describes the treatment of a 55-year-old man who presented with a missing maxillary first molar and mesially inclined neighboring second molar with a severe circumferential bone defect. After bone regeneration therapy with bone grafting, the second molar was uprighted orthodontically to improve the inclination and crown-to-root ratio. These treatments minimized the bone defect and developed a suitable site for an implant in the first molar position. An interdisciplinary approach using periodontal, orthodontic, and prosthodontic treatments can create a more predictable and maintainable situation.

Edentulism in the posterior maxilla can present with compounding variables that make it a difficult region to restore with implants. Pneumatization of the sinus floor is typically accounted for during surgical treatment planning, but other factors such as horizontal ridge deficiency and vertical defects may be overlooked. This report reviews the different classifications used to treat the posterior maxilla and introduces a new system that incorporates all factors critical for implant success. Class A represents abundant bone with >= 10 mm bone height below the sinus floor and >= 5 mm bone width, allowing proper implant placement. Class B indicates barely sufficient bone with 6 to 9 mm bone height below the sinus floor, and this can be further subclassified into division h (horizontal defect; 5 mm bone width), division v (vertical defect; > 3 mm away from cementoenamel junction), and division c (combined horizontal and vertical defect). Class C indicates compromised bone with = 5 mm bone height below the sinus floor, and this can also be subclassified similar to Class B. The ABC classification is a simple system to guide clinicians in proper implant treatment of the posterior maxilla.

The objective of this study was to compare force transmissions in the peri-implant bone region of implants with various conical implant-abutment mating designs. Photoelastic models of solitary Bicon, Astra Tech, and synOcta and monoblock ITI implants were fabricated. Static vertical and 20-degree oblique forces of 75 N were applied on the implants in separate loading cases, and the generation of isochromatic fringes was observed and photographed in the field of a circular polariscope. Three-element strain gauges were bonded on the models in close proximity to the implants. Under the same loading protocol, the strain-gauge signals were digitized by a data-acquisition system and displayed on a computer using corresponding software at a sample rate of 10 kHz, and the principal strains were calculated. Isochromatic fringe orders around ITI and Astra Tech implants were similar at the collar region and slightly higher than around the Bicon implant under both loading conditions. Strains around the Bicon implant were lower than those around all implants tested under vertical loading (P .05), whereas the strains around both ITI implants were similar and lower than those around the Astra Tech implant (P .05). Under oblique loading, strains around both ITI implants were higher than those around other implants tested (P .05). However, these differences do not seem to have any clinical relevance. Internal-cone implants have similar interface force transfer characteristics that resemble a onepart implant. To reduce stresses in the peri-implant region, implant diameter may be more effective than the type of implant.

This retrospective study aimed to radiographically assess sinus floor remodeling after using a modified osteotome technique without graft materials or membranes. After pilot drilling, residual bone was fractured and raised with the schneiderian membrane to the final implant length using osteotomes. Self-tapping implants were placed, and restorations were placed 6 months later. Twenty-four patients were available for follow-up after a mean observation period of 17.6 ± 8.4 months. The implant survival rate at that time was 100%. Bone filling around the implants was measured and compared with baseline digital radiographs. New bone formation was 86.3% ± 22.1% mesially and 89.7% ± 13.3% distally. In nine cases, digital volume tomography was used to verify regeneration. Within the limitations of this study, use of the schneiderian membrane led to considerable bone regeneration, and good clinical success was achieved despite the omission of graft materials.

A modified ridge augmentation technique is introduced for augmenting deficient alveolar ridges in preparation for endosseous implant placement. The technique is based on the principles for guided bone regeneration, in which a created space is kept isolated from the surrounding soft tissues by a resorbable membrane with an excellent extended resorption profile, thus permitting the accrual of bone-formative elements into the graft site. The absorbable membrane is propped up by an autogenous mixture of native corticocancellous bone cores taken in the graft site and reduced to smaller particle sizes and osseous coagulum collected in bone traps and with a special bone scraper. The major advantage of this technique is that all the autogenous bone graft material is obtained from the actual graft site, avoiding second remote intra- or extraoral surgical sites and attendant morbidities. Ridges augmented with this technique permit optimal endosseous implant placement.