Influence of CAD-CAM manufacturing methods on the accuracy and mechanical properties of implant-supported prostheses: A systematic review.

PURPOSE: This systematic review aimed to provide comprehensive insights on the accuracy, fit, and mechanical characteristics of implant-supported computer-aided design and computer-aided manufacturing (CAD-CAM) prostheses, with a focus on milled and 3D-printed approaches. METHODS: The research question focused on implant-supported dental prostheses, comparing different manufacturing techniques (conventional, milled, and 3D-printed) to determine the different factors affecting the mechanical properties and fit of the CAD-CAM implant-supported prosthesis. The eligibility criteria encompassed studies involving implant-supported restorations, clear reporting of manufacturing techniques, and English-language publications from the last decade. The search was conducted across three main databases, MEDLINE, Scopus, and Web of Science in September 2023. Publication details, study characteristics, and methodological details of each included study were described. RESULTS: Of the initial 1964 articles, 581 met the inclusion criteria, and 104 studies were included in the final qualitative analysis. The majority of studies were conducted in the United States, Turkey, and Brazil. Fourteen studies evaluated accuracy parameters, while four studies focused on mechanical characteristics. The studies revealed variability in mechanical properties and marginal and internal fit, with fabrication methods impacting the structural integrity and stress distribution of the prostheses. CONCLUSIONS: The findings suggest that digital manufacturing workflows, both milling and 3D printing, yield acceptable properties for implant-supported restorations with minimal variations in fit and accuracy. Notably, 3D printing and hybrid techniques demonstrate advantages in specific aspects like marginal fit and stress distribution. However, the milled prosthesis provided superior results in flexural strength and fracture resistance compared to conventional methods. Further research is needed to confirm these findings in clinical settings.

Clustering of children's oral diseases in families and villages in a rural setting in Egypt.

BACKGROUND: This study assessed the clustering of children' caries experience, plaque accumulation and gingival inflammation in families and villages in Northwestern Egypt and the factors related to the severity of these conditions. METHODS: This was a secondary analysis of a 2019 household survey of children in villages around Alexandria, Egypt. Clinical examination assessed primary and permanent teeth caries experience (dmft/ DMFT using the World Health Organization criteria), plaque accumulation (Plaque Index (PlI)) and gingival inflammation (Gingival Index (GI)). A child questionnaire assessed child's age, sex, the frequency of toothbrushing (at least twice daily versus less) and frequency of consuming eight types of sugary products (daily sugar consumption score, sum of sugary products consumed daily). Mothers' questionnaire assessed the number of children in the family, mother's education (at least high school versus less), at least twice daily toothbrushing and daily sugar consumption similar to the child. Multilevel regression analyses assessed clustering, calculated by the intraclass correlation coefficient (ICC) of the three conditions in families and villages. Regression estimates (B) and 95% confidence intervals (CIs) of individual and family factors were calculated. RESULTS: Complete data were available for 450 children (246 families, seven villages], mean = 9.9 years-old and 56% females. The mean caries experience score = 3.6, mean plaque index = 1.5 and mean gingival index = 1.2. Caries experience, plaque accumulation and gingival inflammation were not clustered in villages (ICC < 0.01) but clustered in families (ICC = 0.10, 0.44 and 0.29). Child factors significantly improved model fit for caries experience and gingivitis (p < 0.001) but not plaque accumulation (p = 0.90). Family factors did not improve any model fit (p > 0.05). Child's age was significantly associated with caries experience (B= -0.48, p < 0.001) and gingival inflammation (B = 0.032, p < 0.001). Children who brushed their teeth twice daily had significantly more caries experience (B = 1.04, p = 0.01). CONCLUSION: The three oral conditions were not clustered in villages but clustered in families. Plaque accumulation showed the greatest within-family clustering. Family factors were not associated with the three conditions and individual factors indicated the need for interventions to promote preventive behaviors and identify families at risk of oral conditions.

Association between COVID-19 stress, coping mechanisms and stress-related oral conditions among Egyptian adults: a cross-sectional study.

The present study investigated the association between COVID-19 stresses and oral conditions including gingivitis, oral hygiene, oral ulcers, and dry mouth. This was a cross-sectional study that collected data from adults in community settings in Alexandria, Egypt, between October 2021, and February 2022. Gingival condition and oral hygiene were assessed using the gingival and plaque indices. Participants were asked if they experienced oral ulcers during the past week and dry mouth during the past year. COVID-19 fears and coping were assessed using the COVID Stress Scale (CSS), and the Brief Resilience Coping Scale (BRCS), respectively. Oral health behaviors were assessed using the World Health Organization questionnaire. Regression analyses were used to assess the association between the dependent variables (clinically assessed gingival and plaque indices, reported presence of oral ulcers, and dry mouth) and explanatory variables (CSS and BRCS) after adjusting for confounders (COVID-19 status, oral health behaviors, smoking, age in years, sex, and highest educational level). The response rate was 88.8% (373/420). The mean (SD) age = 39.26 (11.45) with 74.3% females and 49.3% reporting completing high school or higher education. The mean (SD) plaque and gingival indices were 1.59 (0.66) and 1.39 (0.59), respectively. Only 20.1% reported the presence of oral ulcers and 41.6% reported xerostomia. Lower plaque score was associated with higher COVID-19 contamination fears (B = - 0.03, 95% CI - 0.05, - 0.02) and higher compulsive checking and reassurance-seeking (B = - 0.02, 95% CI - 0.03, - 0.009). Lower gingival score was associated with higher COVID-19 contamination fears (B = - 0.02, 95% CI - 0.03, - 0.002). Higher odds of reporting dry mouth were associated with greater fear of COVID-19 socioeconomic consequences (AOR = 1.05, 95% CI 1.001, 1.09), and lower coping scores (AOR = 0.93, 95% CI 0.88, 0.99). The findings suggest an association between COVID-19 specific stresses and stress-related oral conditions and shed light on the possible link between mental and oral health, emphasizing the importance of integrated planning of care services.