Regenerative therapy can be applied at hopeless teeth and has the potential to change their prognosis; it is a suitable alternative to extraction of severely compromised teeth with intra-bony defects to or beyond the root apex.

The Ni-Ti systems were more effective and faster than hand files, although all techniques left gutta-percha and sealer remnants on the root canals.

Periodontal regeneration versus extraction and dental implant or prosthetic replacement of teeth severely compromised by attachment loss to the apex: A randomized controlled clinical trial reporting 10-year outcomes, survival analysis and mean cumulative cost of recurrence Abstract Background: Periodontal regeneration can change tooth prognosis and represents an alternative to extraction in teeth compromised by severe intra-bony defects. The aim of this study was to compare periodontal regeneration (PR) with tooth extraction and replacement (TER) in a population with attachment loss to or beyond the apex of the root in terms of professional, patient-reported and economic outcomes. Methods:This was a 10-year randomized controlled clinical trial. 50 stage III or stage IV periodontitis subjects with a severely compromised tooth with attachment loss to or beyond the apex were randomized to PR or TER with either an implant-or a tooth-supported fixed partial denture. Subjects were kept on a strict periodontal supportive care regimen every 3 months and examined yearly. Survival and recurrence analysis were performed.Results: 88% and 100% survival rates were observed in the PR and TER groups.Complication-free survival was not significantly different: 6.7-9.1 years for PR and 7.3-9.1 years for TER (p = .788). In PR, the observed 10-year attachment gain was 7.3 ± 2.3 mm and the residual probing depths were 3.4 ± 0.8 mm. Recurrence analysis showed that the 95% confidence interval of the costs was significantly lower for PR compared with TER throughout the whole 10-year period. Patient-reported outcomes and oral health-related quality-of-life measurements improved in both groups. Conclusions: Periodontal regeneration can change the prognosis of hopeless teethand is a less costly alternative to tooth extraction and replacement. The complexity of the treatment limits widespread application to the most complex cases but provides powerful proof of principle for the benefits of PR in deep intra-bony defect. | 769CORTELLINI ET aL.

The systems tested in this study were effective in shaping curved canals in extracted teeth.

This study analyzed the abilities of ProTaper and GT Rotary files to shape the curved canals of extracted mandibular molars. Twenty mesial canals with curvatures ranging from 23 to 54 degrees (Weine analysis) were radiographically selected from a group of 58 molars. The specimens, divided into two groups, were instrumented using the two systems according to the manufacturer's guidelines. Using a radiographic platform and a contrast medium, reproducible preinstrumentation and postinstrumentation radiographs were taken. A computer analysis allowed magnification and superimposition of the images to measure the preparation asymmetry and the linear amount of dentin removal at five points along the canals and to detect canal aberrations. Instrument failures, working time, and working length changes were recorded. The dentin removal and the mean asymmetry showed no significant differences between the two systems. Neither aberrations nor significant changes in working length resulted, but two instruments separated in each group. Working time was shorter for ProTaper files (p < 0.05).