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.

Long-term scopolamine treatment and dental caries.

OBJECTIVES: To investigate whether scopolamine, an anticholinergic agent which induces hyposalivation, represents a risk factor for the occurrence of dental caries. MATERIALS AND METHODS: A retrospective cohort study was carried out among sailors treated with scopolamine for seasickness. The study population included 370 young healthy male adults (18-30 years old) who served in the Israel Navy between 2012 and 2016. Of these, 66 subjects who were chronically treated with intermittent administration of scopolamine, either by the oral or transdermal route, were assigned to the study group. Documented subject characteristics included age, socioeconomic status, level of education, body mass index, smoking history, and dental hygiene. Follow-up lasted 1 to 3.5 years. RESULTS: Two- to 3.5-year follow-up revealed a higher risk of dental caries in 15 of 16 subjects (93.8%) treated with an average of 50.9 mg scopolamine, in contrast to only 71 of 108 control subjects (65.7%) (RR = 1.43, p = 0.02 [95% CI = 1.18-1.72]). Follow-up for 1-1.5 years revealed a lower occurrence of dental caries in both the study group (11/22, 50.0%) and the control group (46/104, 44.2%). Follow-up of 1.5-2 years also revealed less dental caries, in 16/28 subjects (57.1%) in the study group and 51/92 subjects (55.4%) in the control group. The differences were not statistically significant. CONCLUSIONS: In healthy young adults, prolonged intermittent use of scopolamine was found to be a risk factor for the development of dental caries. CLINICAL SIGNIFICANCE: Dental care and hygiene should be intensified when administering hyposalivatory anticholinergic agents.