Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture

The influence of crown-to-implant ratio on marginal bone levels around splinted short dental implants: A radiological and clincial short term analysis

BACKGROUND The amount of marginal bone resorption around dental implants is considered to have a significant impact on implant stability as well as implant survival rates. PURPOSE The aim of this prospective study was to investigate the influence of prosthetic as well as patient specific factors on marginal bone loss around short dental implants. MATERIALS AND METHODS Seventy-six implants, which supported splinted crowns were included for investigation. All implants were from the same type and had an intraosseous length of 6.5 mm and a diameter of 4.0 mm. Twenty implants were additionally splinted onto longer ones. Measurements of marginal bone loss were performed at a mean of 12.38 months after prosthetic loading and the mean follow-up for clinical evaluation was 20.52 months. RESULTS Overall two implant failures were recorded, revealing a survival rate of 97.3%. Marginal bone resorption around 72 short implants measured 0.71 mm (SD: 0.74 mm) and was found to have a strong correlation with calculated Crown-to-Implant ratio (r = .71; P < .001). Age, gender, insertion torque, implant surface area, location, position, bone quality, and insertion torque did not influence peri-implant bone loss after one year of loading. CONCLUSION Within the limitations of the study, it is suggested that Crown-to-Implant ratios should not exceed 1.7 to avoid increased early marginal bone loss

Prolyl hydroxylase inhibitors increase the production of vascular endothelial growth factor in dental pulp-derived cells

Introduction: Prolyl hydroxylase (PHD) inhibitors can induce a proangiogenic response that stimulates regeneration in soft and hard tissues. However, the effect of PHD inhibitors on the dental pulp is unclear. The purpose of this study was to evaluate the effects of PHD inhibitors on the proangiogenic capacity of human dental pulp–derived cells. Methods: To test the response of dental pulp–derived cells to PHD inhibitors, the cells were exposed to dimethyloxalylglycine, desferrioxamine, L-mimosine, and cobalt chloride. To assess the response of dental pulp cells to a capping material supplemented with PHD inhibitors, the cells were treated with supernatants from calcium hydroxide. Viability, proliferation, and protein synthesis were assessed by formazan formation, 3[H]thymidine, and 3[H]leucine incorporation assays. The effect on the proangiogenic capacity was measured by immunoassays for vascular endothelial growth factor (VEGF). Results: We found that all 4 PHD inhibitors can reduce viability, proliferation, and protein synthesis at high concentrations. At nontoxic concentrations and in the presence of supernatants from calcium hydroxide, PHD inhibitors stimulated the production of VEGF in dental pulp–derived cells. When calcium hydroxide was supplemented with the PHD inhibitors, the supernatants from these preparations did not significantly elevate VEGF levels. Conclusions: These results show that PHD inhibitors can stimulate VEGF production of dental pulp–derived cells, suggesting a corresponding increase in their proangiogenic capacity. Further studies will be required to understand the impact that this might have on pulp regeneration

Graft Remodeling following Transcrestal Sinus Floor Elevation via the Gel-Pressure Technique (GPT) and Pasteous Nano-Crystalline Hydroxyapatite Bone Substitute

Bone grafting of the maxillary sinus is attempted to compensate for sinus pneumatization and permit reliable insertion of endosseous dental implants for prosthetic rehabilitation. The aim of the present clinical investigation was to study bone regeneration four months after transcrestal sinus floor elevation via the Gel-Pressure Technique (GPT) and application of pasteous nano-crystalline hydroxyapatite bone substitute. A total of 25 patients with deficient alveolar ridges in the posterior maxilla (mean residual bone height: 4.7 ± 1.8 mm) were subjected to 32 flapless transcrestal sinus floor augmentations and simultaneous insertion of 40 implants. Sinus membrane elevation height averaged 11.2 ± 2.7 mm and minimal vertical graft resorption of 0.1 mm was observed after four months. Radiographic bone density averaged 460 Hounsfield units in regions adjacent to the native jawbone (1 to 7 mm distance), while reduction of bone density by −7.2%, −11.3%, −14.8%, −19.6% and −22.7% was recorded in more apical regions of 8, 9, 10, 11, and ≥12 mm distance to the original sinus floor, respectively. The results suggest that graft remodeling is completed up to a distance of 7 mm within a healing period of four months after sinus augmentation using nano-crystalline hydroxyapatite bone substitute material