Background In recognition of the risk factors common between oral diseases and various chronic conditions and the intersection between oral health and some sustainable development goals, the current cross-sectional study was designed to quantify the burden of dental caries and identify factors associated with its occurrence in permanent teeth. Methods Using data from Egypt's population-based survey (2013–2014), two individual-level outcomes; past caries experience (DMFT > 0) and presence of untreated carious lesions (DT > 0) were assessed using the WHO basic methods for oral health surveys. Information on potential explanatory variables including sociodemographic characteristics, exposure to fluoridated water, dental attendance, and dental anxiety was gathered using a structured questionnaire. Stratified multistage cluster random sampling was used to recruit survey participants. Multivariable logistic regression was performed to identify significant potential risk factors for caries in the permanent dentition of Egyptians. Findings A total of 9,457 participants were included of which 70.3% had at least one untreated carious lesion. After adjusting for all covariates, analphabetic Egyptians were found to have significantly higher odds of caries experience in permanent dentition DMFT > 0 (OR 1.54, 95% CI [1.20–1.98]), DT > 0 (OR 1.62, 95% CI [1.32–2.00]). Males, however, had significantly lower caries risk DMFT > 0 (OR 0.75, 95% CI [0.67–0.85]), DT > 0 (OR 0.81, 95% CI [0.73–0.89]) when compared to females. Regarding age, mean DMFT scores were significantly lower in age groups (6–15 years) (OR 0.03, 95% CI [0.014; 0.082]), (16– 20 years) (OR 0.09, 95% CI [0.037; 0.23]), and (21–35 years) (OR 0.22, 95% CI [0.09; 0.53]) than among people ≥ 60 years. Conclusion Addressing individual-level caries risk factors should be complemented by addressing upstream factors to reduce burden of untreated dental caries among Egyptians.

Background Despite the interdependence of general and periodontal health, there is paucity of national representative data on the prevalence of periodontal diseases and their associated risk factors in Egyptian population. This cross-sectional study, thus, aimed to assess the prevalence of periodontitis and tooth loss among Egyptian adults and investigate the association between potential risk factors and periodontal diseases. Methods A total of 5,954 adults aged ≥ 20 years were included in this study as a subsample from Egypt’s national oral health survey. Periodontitis was diagnosed with Community Periodontal Index ‘CPI’ scores ≥3 and tooth loss not due to caries was included in the analysis. Socio-demographic data and information on behavioral factors and history of diabetes were gathered in a face-to-face interview. Logistic regression was done to interpret the impact of potential predictors on the incidence of the two selected outcome variables. Results The overall prevalence of periodontitis was 26% and regression analysis revealed that higher odds of periodontitis existed among illiterate participants (OR = 1.74; 95% CI: 1.40–2.17), smokers (OR = 1.93; 95% CI: 1.69–2.20) and rural residents (OR = 1.16; 95% CI: 1.03–1.30). On the other hand, old age, frequency of dental attendance and history of diabetes were the main predictive factors for tooth loss. Conclusions Among Egyptian adults, periodontal diseases were strongly associated with a multitude of modifiable and non-modifiable risk factors and inequalities in distribution of periodontal treatment needs were determined mainly by age, gender, level of education and residency location.