International Journal of Periodontics & Restorative Dentistry, 02/2006

Three sinuses were grafted with a bioactive glass bone substitute (Biogran) mixed with autogenous bone retrieved from intraoral donor sites. In two of the three sinuses a platelet-rich plasma (PRP) gel was added to the graft. Bone biopsies retrieved after 5, 6, and 15 months were analyzed. Micro-computerized tomography (micro-CT) values of total bone volume/total volume (TBV/TV) were very reliable compared to histomorphometry. Biogran mixed with autogenous bone and PRP seems to have a positive effect in sinus grafting, with TBV/TV values ranging between 40% and 68%. Micro-CT results have never been compared with histomorphometry for the evaluation of grafted biomaterials. Micro-CT evaluation of some morphometric parameters was difficult, because the radiodensities of Biogran and a certain grade of bone mineralization were similar.

When mixed with an osteoconductive scaffold, recombinant human plateletderived growth factor (rhPDGF-BB), a potent wound-healing protein, has been shown to promote clinical attachment gain, radiographic bone fill, and regeneration of the periodontium. This human case series evaluated the clinical outcome of rhPDGF with beta tricalcium phosphate (ß-TCP) and a collagen membrane in the treatment of recession-type defects. The control was the clinical gold standard for root coverage: the subepithelial connective tissue graft (CTG). Seven patients with recession defects >= 3 mm in contralateral quadrants of the maxilla, excluding molars, were treated in this series. Patients were followed postoperatively, and healing was evaluated at 8, 16, and 24 weeks, with recession depth as the primary outcome measure. This case series revealed a favorable tissue response to rhPDGF-BB + ß-TCP and a collagen membrane and comparable clinical outcomes to CTG, warranting a controlled clinical trial of greater magnitude.

It was hypothesized that peri-implant tissue around loosening dental implants may contain cytokines with a potential to regulate osteoclasts. Peri-implant and/or gingival samples from loosened implants, chronic periodontitis (CP), and normal controls (n = 10 samples in each group) were analyzed using immunohistochemical staining to observe tumor necrosis factor alpha (TNF-α), interleukin 1-alpha (IL-1α), IL-6, platelet-derived growth factor A (PDGF-A), and transforming growth factor alpha (TGF-α). These cytokines were found in foreign-body giant cells, macrophages, fibroblasts, and epithelial cells. TNF-α, IL-1α, and IL-6 were increased (P < .05; unpaired t test) in peri-implantitis and CP, whereas PDGF-A and TGF-α were not. In conclusion, cytokines with a potential to activate osteoclasts were found in both peri-implantitis and CP, but the cytokine profiles differed in that IL- 1α was the most prevalent cytokine in the former and TNF-α was the most common in the latter. These cytokines may contribute to peri-implant bone loss/loosening by stimulating formation and activity of osteoclasts and might be an amenable target for local therapies with cytokine modulators.

In the treatment of single-tooth gaps, the resin-bonded fixed partial denture (FPD) has established itself as an alternative treatment modality. With the advent of high-strength ceramics, such as aluminum oxide ceramics, it appeared to be possible to fabricate all-ceramic resin-bonded FPDs without a metal reinforcement. However, fractures of the traditional two-retainer design of these restorations occurred quite frequently. It was proposed to change the two-retainer design to a single-retainer design with the hope that the survival rate could be improved. Nevertheless, the use of aluminum oxide ceramics can be problematic. The present study strongly suggests that the clinical performance of resin-bonded FPDs made of a high-strength glass-ceramic is in large measure dependent on their design.

The technique of the osteotome-mediated transcrestal sinus floor elevation is described in a series of case reports. Fifty-five patients received a total of 66 implants over a period of 6 years. Bio-Oss was added in more than 60% of cases to increase the stability of the lifted area. The surgical procedure appeared to be a safe method that was well supported by the patients. It was applied for different prosthetic indications in partially and completely edentulous situations. The survival rate of the implants during the healing phase was 98.5%, and it was 100% after loading. The patients' responses to the Summers technique were evaluated by means of short interviews and visual analog scales (VAS), and the answers were compared with those from a group of patients who had received implants in the same location during the same period but without the osteotome technique. The answers regarding pain were not different between the groups. However, significantly more patients who had received the implants by means of the osteotome technique judged the surgical procedure as highly uncomfortable. It is concluded that patients need to be well prepared for the procedure.

The aim of this study was to investigate the effects of a combination of porous bovine inorganic bone graft (Bio-Oss) and bilayer porcine collagen membrane (Bio-Gide) on refractory one-wall intrabony defects in dogs. Bio-Oss and Bio-Gide were applied into the refractory one-wall intrabony defect. The contralateral sites were used as controls (without the application of Bio-Oss and Bio-Gide). At 24 weeks after surgery, similar pocket depths were found in both groups. However, histologic observation revealed an infiltration of inflammatory cells in the control group caused by poor gingival architecture, whereas only a few of the experimental sites showed inflammatory infiltration. In addition to the healthy gingival tissue, periodontal tissue regeneration was observed in the experimental group. The combination of Bio-Oss and Bio-Gide was an effective treatment for refractory one-wall intrabony defects in dogs.

Extraction sites in the esthetic zone present an obvious restorative challenge. This case report describes a surgical technique for the preservation of anterior esthetics that combines minimally invasive extraction with immediate implant placement. This single-stage approach preserves site morphology by protecting and supporting existing hard and soft tissues. Clinical success appears to be attributable to several important features of the technique. The first step involves the elevation, luxation, and extraction of the tooth using either a flapless or minimally invasive approach that reduces trauma to the adjacent tissues. The second step involves appropriate orientation, placement, and stabilization of the implant to preserve facial bone and soft tissue contours. Implant placement is accomplished using particulate freeze-dried bone allograft and enamel matrix derivative to achieve ridge preservation and bone augmentation. The composite graft material is considered critical for predictably resolving osseous voids and promoting implant integration, and consideration is given to the concept of osteogenic "jumping distance" between the implant and the eccentric walls of the alveolus. Finally, preservation of the soft tissue architecture during wound healing is achieved by placement of either a fixed or removable restoration. Consistent implant integration and preservation of the hard and soft tissue complexes have been achieved using this approach.

New tooth-colored restorative materials have been developed with the goal of replacing amalgam. These restoratives are marketed as packable composite and ormocer. The purpose of the present study was to compare the compressive shear bond strengths of these new materials with that of hybrid composite and amalgam as core materials. Standardized core buildups were made on four groups of extracted molars, with 10 teeth per group. Three tooth-colored restorative materials (Filtek Z 250, Filtek P 60, and Definite) and an amalgam (SDI Permite) were used. Specimens were placed in a special jig at a 45-degree angle. The compressive shear bond strength was obtained using a universal testing machine. The Kruskal-Wallis test was used to compare the groups, and pairwise comparisons were made by Mann-Whitney U test (P < .05). Filtek P 60, a packable composite resin, had the greatest compressive shear bond strength values in all instances, and the ormocer (Definite) had the lowest. The strengths of packable composite, hybrid composite, and amalgam as core materials were not significantly different (P > .05).

A case of necrotizing ulcerative periodontitis (NUP), the most severe inflammatory periodontal disorder caused by plaque bacteria, is shown. Clinically, the gingiva showed distinct signs of ulceration, and radiography revealed horizontal bone loss. Indirect immunofluorescence, carried out on frozen sections of tissue specimens obtained from the NUP lesion, exhibited clear expression of atypical keratin K19, particularly in basal cells, when compared to noninflamed gingiva. Moreover, NUP tissue showed extensive intraepithelial abundance for the basement membrane component laminin-1/10 and the extracellular matrix molecule tenascin. Strong expression of integrin subunit αv and matrix metalloproteinase-13 in conjunction with interleukin 1-beta further discriminated NUP gingival epithelium from normal tissue. The results suggest that NUP is associated with changes in the expression and topography of the analyzed molecules in the gingival epithelium, which in turn may reflect the fast progression of the disease.