Introduction of a prediction model to assigning periodontal prognosis based on survival time.

AIMS: To develop a prediction model for tooth loss due to periodontal disease (TLPD) in patients following periodontal maintenance (PM), and assess its performance using a multicentre approach. MATERIAL AND METHODS: A multilevel analysis of eleven predictors of TLPD in 500 patients following PM was carried out to calculate the probability of TLPD. This algorithm was applied to three different TLPD samples (369 teeth) gathered retrospectively by nine periodontist, associating several intervals of probability with the corresponding survival time, based on significant differences in the mean survival time. The reproducibility of these associations was assessed in each sample (One-way ANOVA and pairwise comparison with Bonferroni corrections). RESULTS: The model presented high specificity and moderate sensitivity, with optimal calibration and discrimination measurements. Seven intervals of probability were associated with seven survival time and these associations contained close to 80% of the cases: the probability predicted the survival time at this percentage. The model performed well in the three samples, as the mean survival time of each association were significantly different within each sample, while no significant differences between the samples were found in pairwise comparisons of means. CONCLUSIONS: This model might be useful for predicting survival time in different TLPD samples.

The effect of placing a bone replacement graft in the gap at immediately placed implants: a randomized clinical trial.

OBJECTIVE: To assess the added value of using a bone replacement graft in combination with immediate implants in reducing the bone dimensional changes occurring in the residual ridge. MATERIAL AND METHODS: Randomized parallel controlled clinical trial to study the efficacy of grafting with demineralized bovine bone mineral with 10% collagen (DBBM-C) in the gap between the implant surface and the inner bone walls when the implants were immediately placed in the anterior maxilla. The changes between implant placement and 16 weeks later in the horizontal and vertical crestal bone changes in relation to the implant were evaluated through direct bone measurements using a periodontal probe. Mean changes were compared between the experimental and control sites using parametric statistics. RESULTS: A total of 86 implant sites in 86 subjects were included in the analysis (43 in the test group and 43 in the control group). The horizontal crest dimension underwent marked changes during healing mainly at the buccal aspect of the alveolar crest where this reduction amounted to 1.1 (29%) in the test group and 1.6 mm (38%) in the control group, being these statistically significant (P = 0.02). This outcome was even more pronounced at sites in the anterior maxilla and with thinner buccal bone plates. CONCLUSIONS: In conclusion, the results from this clinical trial demonstrated that placing a DBBM-C bone replacement graft significantly reduced the horizontal bone resorptive changes occurring in the buccal bone after the immediate implantation in fresh extraction sockets.

An alternative multiple pontic design for a fixed implant-supported prosthesis.

In situations of moderate residual ridge resorption where multiple tooth replacement is needed, and where the patient desires a fixed implant-supported restoration, it is challenging to design a pontic-tissue interface. The semiconvex multiple pontic design described in this article, with its mucosal contact exerted with moderate pressure, is proposed to circumvent the problems encountered with the plaque accumulation, maintenance conditions, phonetics, and compromised esthetics frequently encountered in these patients. The use of a screw-retained, implant-supported restoration is also emphasized to allow for sufficient tissue contact during placement of the prosthesis and for prosthesis retrievability for maintenance or technical reasons.