Retrograde peri-implantitis: incidence and possible co-existing factors: a retrospective analysis.

OBJECTIVES: To evaluate the incidence of retrograde peri-implantitis (RPI) generally and the incidence of RPI with an endodontic-treated adjacent tooth and/or a periapical radiolucency. METHOD: The retrospective case-control study included the follow-up periapical images of single dental implants. Two calibrated graduate endodontic residents evaluated simultaneously the presence of RPI and the adjacent teeth status (a previous root canal treatment (RCT) and the periapical status). RESULTS: Six hundred and eleven dental implants were included in this study. Twenty-three implants with RPI were detected (the incidence of RPI was 3.7%). Thirty-one adjacent teeth to the implants with RPI were recognized. Out of them, seven teeth had a previous RCT and periapical radiolucency or no RCT and periapical radiolucency. The odds ratios for RPI in an implant with periapical radiolucency or with RCT at the adjacent tooth are 6.67 (95% CI 2.7-16.5), P < 0.05; and 0.11 (95% CI 0.007-1.9), P > 0.05 respectively. CONCLUSIONS: Based on periapical radiographs, the RPI incidence was 3.7% in the present study. The incidence of RPI increased in cases with adjacent teeth that had periapical radiolucency. Previous RCT in teeth adjacent to implants without apical radiolucency is not correlated with RPI.

Evaluation of the width of the alveolar bone in subjects with different gingival biotypes: A prospective cohort study using cone beam computed tomography.

OBJECTIVE: To examine the correlation between the gingival biotype and the morphology of the alveolar bone in human subjects, assessing the clinical and the practical values of these findings. METHOD AND MATERIALS: Thirty-five subjects were enrolled. The labial plate thickness was measured by cone beam computed tomography (CBCT). The correlation between CBCT and probe transparency measurements was analyzed with regard to tooth type (canine or central incisor). Additional data analysis included possible correlation to gender and smoking status. RESULTS: Of the patients, 57% (20/35) were female; 23% (8/35) were smokers; 78% (25/32) of maxillary teeth had thin biotype compared to 50% (19/38) of mandibular teeth; 63% (10/16) and 32% (6/19) of the patients had thin biotype in maxillary and mandibular teeth respectively. More than 30% of the subjects demonstrated different biotypes in the same jaw at different sites. The probe transparency through the soft tissue at the maxillary canine was positively correlated with the width of the facial bone plate at the alveolar crest (P = .026). CONCLUSION: Biotype can vary in the same subject at different sites. Only the maxillary canine's biotype correlated with the facial plate width.