Fracture resistance of CAD/CAM endocrowns made from different materials in maxillary premolar interproximal defects.

OBJECTIVES: This in vitro study aims to compare the fracture resistance of three CAD/CAM materials used in endocrown restoration of interproximal defects in maxillary premolars. MATERIALS AND METHODS: 45 maxillary premolars extracted as part of orthodontic treatment were included. Following standardized root canal treatment, all teeth were prepared into Mesial-Occlusal (MO) cavity types. The samples were then randomly divided into three groups: LD [repaired with lithium disilicate glass ceramics (IPS e.max CAD)], VE [treated with polymer-infiltrated ceramics (Vita Enamic)], and LU [repaired with resin-based nanoceramics (Lava Ultimate)]. Axial static loading was applied using a universal testing machine at 1 mm/min until fracture, and fracture resistance and failure modes were recorded. RESULTS: Regarding Fracture Resistance Values (FRVs), the LD group exhibited significantly higher values than the other two groups, VE (P = 0.028) and LU (P = 0.005), which showed no significant difference (P = 0.778). On the other hand, regarding failure modes, the LD group had a higher prevalence of irreparable fractures compared to the other two groups, VE (P < 0.001) and LU (P < 0.001), which showed no significant difference. CONCLUSIONS: Although lithium disilicate glass ceramics exhibited higher FRVs, they had a lower repair probability. In contrast, polymer-infiltrated ceramics and resin-based nanoceramics contributed to tooth structure preservation. CLINICAL RELEVANCE: For maxillary premolars with interproximal defects following root canal treatment, resin ceramic composites are recommended for restoration to enhance abutment teeth protection.

Association between life's essential 8 and periodontitis: a population-based study.

BACKGROUND: The American Heart Association has developed a novel cardiovascular health indicator called Life's Essential 8 (LE8). However, no one has reported using LE8 to assess periodontitis. This study aimed to investigate the association between LE8 and periodontitis in American adults. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014 were used for this investigation. LE8 was the independent variable, and it is divided into three grades: high, moderate, and low. Periodontitis was the dependent variable, and the classification of periodontitis was based on the criteria of Eke in 2012. Multivariable logistic regression models were used to explore the relationship between LE8 and periodontitis. RESULTS: A total of 9,039 participants with an average age of 52.16 ± 14.21 years were enrolled in this study, of whom 48.29% were male and 51.71% were female. The mean and standard deviation of LE8 was 66.29 ± 14.57, and the prevalence of periodontitis was 50.48% overall. The LE8 score and periodontitis in the fully adjusted logistic regression model showed a negative correlation (OR = 0.98; 95% CI, 0.98-0.99, p < 0.001). This result persisted when Life's Essential 8 was categorized into low, moderate, and high groups. Compared with those in the lowest group, those in the highest LE8 group had a 47% decreased risk of periodontitis (OR = 0.53; 95% CI, 0.46-0.66, P < 0.001). CONCLUSIONS: This cross-sectional investigation revealed a negative relationship between the LE8 score and the likelihood of periodontitis.

Association between periodontitis and breast cancer: two-sample Mendelian randomization study.

OBJECTIVES: The purpose of this study was to investigate whether there is a causal relationship between periodontitis and breast cancer by Mendelian randomization analysis. MATERIALS AND METHODS: We performed a two-sample bidirectional Mendelian randomization (MR) analysis using publicly released genome-wide association studies (GWAS) statistics. The inverse-variance weighted (IVW) method was used as the primary analysis. We applied complementary methods, including weighted median, weighted mode, simple mode, MR-Egger regression, and MR-pleiotropy residual sum and outlier (MR-PRESSO) to detect and correct for the effect of horizontal pleiotropy. RESULTS: IVW MR analysis showed no effect of periodontitis on breast cancer (IVW OR=0.99, P =0.14). Similarly, no significant causal relationship between breast cancer and periodontitis was found in reverse MR analysis (IVW OR=0.95, P =0.83). The results of MR-Egger regression, weighted median, and weighted mode methods were consistent with those of the IVW method. Based on sensitivity analyses, horizontal pleiotropy is unlikely to distort causal estimates. CONCLUSIONS: Although observational studies have reported an association between periodontitis and breast cancer, the results of our MR analysis do not support a causal relationship between periodontitis and breast cancer. CLINICAL RELEVANCE: Mendelian randomization study can more clearly analyze the causal relationship between periodontitis and breast cancer, in order to provide a certain reference for clinicians and deepen the understanding of the relationship between periodontitis and breast cancer, to explore more possible associations between periodontitis and systemic diseases.

Association between skull bone mineral density and periodontitis: Using the National Health and Nutrition Examination Survey (2011-2014).

BACKGROUND AND OBJECTIVE: Bone mineral density (BMD) and periodontitis have been the subject of many studies. However, the relationship between skull (including mandible) BMD and periodontitis has not been extensively studied. An objective of this cross-sectional study was to examine the relationship between skull BMD and periodontitis using data from the National Health and Nutrition Examination Surveys (NHANES) for 2011-2012 and 2013-2014. MATERIALS AND METHODS: From NHANES 2011-2014, 3802 participants aged 30-59 were selected. We divided the skull BMD level into quartiles to check the distribution of variables. Periodontitis was defined by the Centers for Disease Control and Prevention (CDC) and the American Association of Periodontology (AAP) in 2012. Multivariate logical regression analysis was used to explore the independent relationship between skull BMD and periodontitis. The generalized additive model (GAM), smooth curve fitting (penalty spline) and threshold effect analysis was used to evaluate dose-response relationship between skull BMD and periodontitis and the potential nonlinear relationship between skull BMD and periodontitis. Finally, subgroup analysis and interaction test were conducted to determine the role of covariates between skull BMD and periodontitis. RESULTS: The overall average skull BMD of 3802 participants was 2.24g/cm2, the average age was 43.94 years, and the prevalence of periodontitis was 41.03%. In the fully adjusted logistic regression model, skull BMD and periodontitis showed an independent negative correlation (OR 0.73, 95% CI 0.59-0.90, P = 0.0032) and a linear relationship. Compared with the lowest quartile array (Q1:1.22-1.98) of skull BMD, the highest quartile array(Q4: 2.47-3.79) had a significantly lower risk of periodontitis (OR 0.70,95% CI 0.56-0.87, P = 0.0014). Subgroup analysis showed a highly consistent negative correlation between skull BMD and periodontitis. In the interaction test, people with moderate poverty income ratio (1.57-3.62) and those who had more than 12 alcohol drinks in the past year had a lower risk of periodontitis. CONCLUSIONS: This result suggested that periodontal disease can be related to low skull BMD, for those people, oral hygiene and health care should be more closely monitored. Validation of our findings will require further research.

Reverse causal relationship between periodontitis and shortened telomere length: Bidirectional two-sample Mendelian random analysis.

Background: Observational studies have demonstrated a link between shortened telomere lengths(TL) and chronic periodontitis. However, whether the shortened TL is the cause or the result of periodontitis is unknown.Therefore, our objective was to investigate a bidirectional causal relationship between periodontitis and TL using a two-sample Mendel randomized (MR) study. Methods: A two-sample bidirectional MR analysis using publicly available genome-wide association study (GWAS) data was used. As the primary analysis, inverse variance weighting (IVW) was employed. To identify pleiotropy, we used leave-one-out analysis, MR-Egger, Weighted median, Simple mode, Weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO). Results: In reverse MR results, a genetic prediction of short TL was causally associated with a higher risk of periodontitis (IVW: odds ratio [OR]: 1.0601, 95% confidence interval [CI]: 1.0213 to 1.1002; P =0.0021) and other complementary MR methods. In the forward MR analysis, periodontitis was shown to have no significant effect on TL (IVW: p = 0.7242), with consistent results for the remaining complementary MR. No pleiotropy was detected in sensitivity analysis (all P>0.05). Conclusion: Our MR studies showed a reverse causal relationship, with shorten TL being linked to a higher risk of periodontitis, rather than periodontitis shorten that TL. Future research is needed to investigate the relationship between cell senescence and the disease.