A unique investigation of thallium, tellurium, osmium, and other heavy metals in recurrent pregnancy loss: A novel approach.

OBJECTIVE: To study the impact of heavy metals especially tellurium, thallium, and osmium, in recurrent pregnancy loss (RPL) and to study their association with antioxidant status and DNA damage. METHODS: This case-control study included women with RPL (n = 30) and healthy pregnant women as control (n = 30). Following blood collection, serum levels of thallium, tellurium, osmium, lead, mercury, and cadmium were estimated by inductively coupled plasma mass spectrophotometer. RESULTS: Women with RPL exhibited significantly higher levels of heavy metals (P < 0.001) when compared with control women. Intriguingly, increased levels of serum thallium, tellurium, osmium, and lead were negatively correlated with total antioxidant status (P < 0.05). Further, the RPL group demonstrated strong positive correlation between heavy metals (thallium, tellurium, osmium, lead) and DNA damage (P < 0.05). No significant correlation between other heavy metals and markers of cellular damage was noted. CONCLUSION: Enhanced levels of heavy metals in women with RPL and correlation of thallium, tellurium, osmium, and lead with markers of cellular damage reflect the role of heavy metal poisoning, especially thallium, tellurium, and osmium, as potential risk factor in the etiology underlying recurrent miscarriage.

Clinical outcomes of single crown and 3-unit bi-layered zirconia-based fixed dental prostheses: An upto 6- year retrospective clinical study: Clinical outcomes of zirconia FDPs.

OBJECTIVES: The aim of this retrospective clinical study was to evaluate the survival and the occurrence of technical and biological complications in bi-layered zirconia-based (Zi) single crown and 3-unit fixed dental prostheses (FDPs). Also, the study aimed to analyze the effects of tooth vitality (vital versus non-vital), abutment location (anterior versus posterior), and luting cement (self-adhesive resin versus resin-reinforced glass ionomer) on clinical outcomes. METHODS: A total of 147 prostheses (in 94 patients) placed by undergraduate dental students in a university dental center during the period 2015-2021 were examined clinically using modified United States Public Health Service (USPHS) and California Dental Association (CDA) criteria. The mean duration of follow-up was 37 months (range, 6 - 63 months) for the single crowns (n = 77) and 25 months (range, 6 - 68 months) for the 3-unit FDPs (n = 70). Data were descriptively analyzed to determine the types and rates of complications based on USPHS and CDA criteria. The Kaplan-Meier survival estimation method was used to determine the cumulative survival and success rates of the prostheses (α=0.05). Differences in clinical outcomes (survival or failure) according to tooth vitality, luting cement, and location were statistically analyzed using cross-tabulations and Ð¥2 test (α=0.05). RESULTS: The Kaplan-Meier cumulative survival rate was estimated as 96% for the Zi 3-unit FDPs after 5.5 years, and 90% for the Zi single crowns after 4.8 years. The 5-year estimated success rate was 68% for both 3-unit FDPs and single crowns. Seven (9.1%) 77Zi single crowns and 70 2 (2.9%) Zi 3-unit FDPs were recorded as failures with occlusal roughness being the most commonly-observed complication (crowns: 4 [5.6%]; 3-unit FDPs: 8 [11.4%]). In terms of clinical outcomes, statistically significant differences were found between all included vital and non-vital teeth (p = .006), and cement types (p = .028). Taking single crowns alone, significant differences in clinical outcomes according to tooth vitality were noted (p = .036), but not for PFDPs. The location of the prostheses did not produce any significant differences in the clinical outcomes, for both prostheses types independently or combined (p > .05). CONCLUSIONS: The estimated cumulative survival rates in this study for single crowns and 3-unit Zi FDPs concurred with the ranges reported in systematic reviews. Zi-based prostheses on vital teeth produced better clinical outcomes than those placed on non-vital teeth, and type of luting cement influenced the final clinical outcome. CLINICAL SIGNIFICANCE: Zi crowns and 3-unit PFDPs fabricated using the specific CAD-CAM system used in the controlled environment of this study showed good clinical performance with minimal veneer porcelain chipping. Root canal treated teeth seem to be at higher risk for failure of Zi prostheses compared with vital teeth.