Effect of pulp chamber depth on failure load and mode of failure of CAD/CAM endocrowns.

AIM: The present study aimed to investigate the effect of pulp chamber depth on the failure load and mode of failure of CAD/CAM endocrowns. MATERIALS AND METHODS: Thirty mandibular molars were sectioned above the cementoenamel junction (CEJ), followed by root canal treatment. Teeth were sectioned at a level of 1.5 mm above the CEJ, arranged from the lowest to the highest depths, and divided into three groups (n = 10): group SE: Shallow pulp chamber (1.42 to 2.17 mm); group IE: Intermediate pulp chamber (2.25 to 3.17 mm); group DE: Deep pulp chamber (3.33 to 5.17 mm). CAD/CAM endocrowns were fabricated by milling lithium disilicate ceramic blocks and were cemented using resin cement. Teeth were embedded in acrylic resin at 2 mm below the CEJ, and a compressive load was applied to create a 45-degree angled functional loading simulation until the occurrence of failure. RESULTS: The mean failure loads were highest in group DE (1893.75 ± 496.08 N) compared with groups IE (1103.71 ± 254.59 N) and SE (1084.63 ± 240.92 N), with statistically significant differences between group DE and both groups IE and SE (P < 0.001). Pearson correlation coefficient (PCC) revealed a strong positive correlation between the pulp chamber depth and failure load of the endocrowns. The failure mode for all samples was catastrophic failure. CONCLUSION: The pulp chamber depth affected the failure load of the teeth restored with endocrowns. The failure loads were higher in teeth with a greater pulp chamber depth. (Int J Comput Dent 2023;26(1): 31-0; doi: 10.3290/j.ijcd.b3818295).

The epidemiology of edentulism and the associated factors: A literature Review.

Considering the advancement of curative and preventive dentistry, edentulism is still a challenging problem for healthcare providers all over the world. Dental caries and periodontal diseases are the main causative factors to teeth loss and eventually, if untreated, lead to edentulism. The socioeconomical factors also contribute to the edentulism as it has an association with education and income status. This literature review will put some highlights in the epidemiology and etiology of edentulism, its prevalence, and the association with the social-economical factors.

A Comparison of Dental Caries in Urban and Rural Children of the Riyadh Region of Saudi Arabia.

Background and Aim: The data presented in this study aimed to document caries prevalence and severity among a representative sample of 6, 12, and 15 years old Saudi Children. Methodology: The study examined a total of 1,986 school children from 75 schools in urban and rural areas of Riyadh region, Saudi Arabia. Children having one or more dental caries lesion were used to determine prevalence of dental caries. Total number of decayed filled teeth (dft) was used to assess caries severity in the 6 years group while the DMFT was used to assess severity of dental caries at the 12 and 15 years age group. Results: The caries prevalence was 85.77% in the 6 years group, 64.98% in the 12 years group, and 71.35% in the 15 years group. Mean dft was 1.4 (SD ± 1.1). The mean DMFT was 1.72 (SD ± 0.49) at 12 years and 2.66 (SD ± 0.55) at 15 years. Both caries rate and severity were higher in rural areas than urban areas although the differences were not statistically significant. Conclusion: The results of this study suggest that the prevalence and severity of dental caries in Saudi Arabia remain high, when compared to global averages.

Dentists' opinion and knowledge about preventive dental care in Saudi Arabia: a nationwide cross-sectional study.

AIM: The aim of this study was to determine the dentists' opinions on causes for high prevalence of dental caries in the country and to assess their level of knowledge about preventive dental care. MATERIALS AND METHODS: A questionnaire based national crosssectional survey among 500 dentists was conducted under the auspices of Directorate of Dentistry, Ministry of Health. The data was analyzed using SPSS software version 11.0 and descriptive statistics were obtained. RESULTS: The response rate was 87.8% (n = 439). 83% of dentists identified poor oral hygiene as the major reason for high prevalence of caries, only 39% of patients reportedly brushed teeth at least once a day, oral prophylaxis (83%) is the most common preventive practice followed, social factors (62.5%) are the most challenging barriers in preventive dental programs, 71.3% always give chair side dental health education, school based programs (66.6%) are most effective tools for dental health education. CONCLUSION: Majority of dentists in Saudi Arabia are adequately informed and motivated toward preventive dental care but they are in need of further support from policy makers to enhance preventive dental programs in the Kingdom. CLINICAL SIGNIFICANCE: Oral hygiene should be improved in the country by reaching out to the entire community through extensive and continued education programs.

Single-tooth implant restorations: a retrospective study.

Single-tooth implant restorations are a demanding clinical endeavor. Predictable results can be achieved when clinicians adhere to a recommended protocol for placement and reconstruction. As the demand to use implants to replace single missing teeth increased, so did the demand for superior esthetic outcome and immediate insertion and loading. The present study presents a 6-year audit of single-tooth implant restorations at Riyadh Dental Centre with a survival probability of 93.8% after a 5-year period. The recent trend of immediate insertion and loading results was also encouraging but still needs technical refinement as well as long-term follow-up review between different protocols.

The effect of repeated torque on the ultimate tensile strength of slotted gold prosthetic screws.

STATEMENT OF PROBLEM: Repeated torque may alter the mechanical properties and fracture resistance of certain prosthetic retaining screws. PURPOSE: This study evaluated the effect of repeated torque and salivary contamination on the ultimate tensile strength of one type of slotted gold prosthetic retaining screw. MATERIAL AND METHODS: Forty-five slotted gold prosthetic screws from the same manufacturer (Implant Innovations) were divided randomly into 9 groups of 5 screws each, with group 0X being an unused control. Groups 1XL, 5XL, 10XL, and 20XL were lubricated with human saliva, tightened to 10 Ncm, and removed 1, 5, 10, and 20 times, respectively. This procedure was performed in an unused stack of implant components consisting of an implant, an abutment cylinder and screw, and a gold cylinder. Groups 1XN, 5XN, 10XN, and 20XN were not lubricated. A custom load cell, load frame, and strain gauge torque wrench with associated electronics were used to apply torque; ultimate tensile strength was measured on a universal testing machine. Fracture load values were analyzed against torque cycles with 1-way analysis of variance and a Tukey test (P<.05). Differences between the 2 conditions (lubricated and nonlubricated) were characterized with Student's t test (P<.05). RESULTS: Mean fracture load values ranged from 97.6 +/- 2.2 kg (group 0X) to 102.0 +/- 2.1 kg (group 5XN). Analysis of variance and Tukey's test revealed no significant differences between the lubricated and nonlubricated conditions for all groups and no significant reduction of tensile strength. For 2 of the nonlubricated groups, 5XN and 20XN, a significant increase in fracture load values was recorded (P=.02 and P=.03, respectively). CONCLUSION: Within the limitations of this study, the results suggest that the slotted gold prosthetic screw tested can be tightened and removed up to 20 times without any effect on its ultimate tensile strength. The use of human saliva as a lubricant during torquing also had no apparent effect on ultimate tensile strength.