Objectives: This study assessed the impact of prosthodontic care on daily performance of patients with removable partial dentures (RPDs). Materials and Methods: This longitudinal study was conducted on consecutive patients over 20 years of age who required RPDs presenting to an outpatient prosthodontic clinic over a 2-year period (2022-2023). Data on socio-demographics, history of tooth replacement/denture use, maintenance practices, attendance to recall visits, and impact on daily activities were recorded after using the RPDs by the participants. Data were also collected over the course of recall appointments using structured questionnaires according to the American College of Prosthodontists’ denture care and maintenance guidelines and the oral impacts on daily performance (OIDP) questionnaire. Comparisons were made by the Kruskal Wallis and student t tests and multiple logistic regression (alpha=0.05). Results: A total of 332 participants with a mean age of 45.69±17.90 years were evaluated, including 49.7% males and 50.3% females. The highest percentage of recall visits was at 1 week (26.8%). Attendance at recall appointments (P=0.00) and sleeping with RPD (P=0.001) were significantly associated with OIDP scores. Sleeping with RPDs (P=0.001) was significantly related to, and acted as a predictor of OIDP score [X2(4)=15.46, P<0.04]. Conclusion: Recall attendance was low, and overnight denture use and frequent recall visits had a greater impact on daily activities than other factors. Sleeping with dentures was a predictor of impact of denture use on daily performance.
Objectives: This study aimed to examine the relationship of pulp-to-enamel volume ratio of third molars on cone-beam computed tomography (CBCT) images with chronological age, in order to create a regression equation that can be used to estimate age in both males and females. Materials and Methods: A total of 122 impacted mandibular third molars of patients over the age of 18 years, who were referred to the dental clinic of Tehran University of Medical Sciences were analyzed in this cross-sectional study. CBCT images in DICOM format were imported into 3D Slicer software for calculation of pulp and enamel volumes. Data were analyzed by multiple linear regression (backward method) and Pearson's correlation coefficient (alpha=0.1 in regressions, and 0.05 in correlations). Results: There was a significant inverse correlation between the pulp-to-enamel volume ratio and chronological age in both males (-0.55, P<0.001) and females (-0.517, P<0.001), as determined by the Pearson’s correlation coefficient. The mean absolute error (MAE) was lower in females (4.67 years) than in males (8.02 years) when using the pulp-to-enamel volume ratio as the sole independent variable. The regression formula that utilized the pulp-to-enamel volume ratio as a sole independent variable was able to estimate age in both sexes. Conclusion: The results showed a statistically significant correlation between age and pulp-to-enamel volume ratio of impacted mandibular third molars, and this ratio may be applied as a useful index for age estimation.
Objectives: Silicone facial prostheses are replaced after a relatively short period of clinical service, mainly due to the decline in their physical and mechanical properties. This study aimed to investigate some mechanical and physical properties of VST-50 maxillofacial silicone after incorporating thymol micro-powder into its matrix. Materials and Methods: In this in vitro study, room-temperature vulcanised VST-50 maxillofacial silicone and thymol micro-powder were used to prepare the study specimens according to the findings of a pilot study. Sixty specimens were prepared and assigned equally and relevantly to three tests (tensile strength/elongation percentage test, and surface roughness test). Each test encompassed three groups (n=10). According to thymol content percentage, the study groups were customised as: group A: control (without additive), experimental groups B and C with 0.75wt% and 1wt.% thymol additive, respectively. An Instron universal testing machine was used to investigate the tensile strength and elongation percentage, and a profilometer was used to test the surface roughness. ANOVA and post-hoc test were used to analyze the results (alpha 0.05). Results: Statistically, group B showed a significantly higher mean tensile strength (mean difference: -3.055 N/mm2; P<0.001) and elongation percentage (mean difference: -157.9885%; P=0.003). However, group C showed a significantly lower surface roughness (mean difference: 0.1172µm; P<0.001). Conclusion: According to the results of this in vitro study, thymol micro-powder appears to be a promising additive that could reinforce some physical and mechanical properties of medical-grade maxillofacial silicone.
Objectives: This study compared the penetration depth of three different root canal sealers—AH Plus resin-based, Apexit Plus calcium hydroxide (CH)-based, and BioRoot RCS bioceramic-based sealers—into dentin after removal of CH intracanal medicament. Materials and Methods: In this in vitro study, 60 extracted single-rooted mandibular premolars were decoronated with a diamond disc under water cooling to a standard length of 16mm; 12 samples were selected as control, and the rest received CH mixed with rhodamine dye as an intracanal medicament. Two weeks later, CH was removed by manual filing and irrigant activation using EndoActivator. Samples were then divided into 3 groups (n=12) depending upon the sealer used as AH Plus, Apexit Plus, and Bioroot RCS sealer. All sealers were combined with fluorescein dye, and obturation was performed using F3 gutta-percha with lateral compaction technique. After 2 weeks, the teeth were transversally sectioned into coronal, middle, and apical thirds. The penetration depth of sealers was measured via an imaging software. Statistical analysis was performed using ANOVA followed by the Tukey’s post-hoc test (alpha=0.05). Results: A statistically significant difference was observed among the groups (P<0.05). The penetration depth of sealers was the lowest in the apical third, and the highest in the coronal third in all three groups. BioRoot RCS showed the highest penetration depth at all three levels, despite CH medicament remnants. Conclusion: Bioroot RCS bioceramic sealer was superior to AH Plus resin-based and Apexit Plus CH-based sealers regarding penetration depth into dentin after removal of CH intracanal medicament.
Objectives: This study evaluated the reliability of panoramic radiography in comparison with lateral cephalometry for angular measurements in different skeletal classes. Materials and Methods: In this retrospective study, the gonial angle, the angle formed between the palatal plane and the Frankfort plane (palatal plane inclination), and the angle formed between the incisal edge of the upper incisor and the Frankfort plane (upper incisor vertical index) were measured on panoramic and lateral cephalometric radiographs of 278 patients in three skeletal classes. Intraclass correlation coefficient (ICC) was calculated to compare panoramic and lateral cephalometric radiographs. Paired t-test was used for comparison of the right- and left-side angles on panoramic radiographs. Results: The ICCs were 0.941, 0.927, and 0.954 for the gonial angle, 0.650, 0.605, and 0.320 for the palatal plane inclination, and 0.812, 0.810, and 0.758 for the maxillary incisor vertical index in skeletal Class I, II and III patients, respectively. The ICCs were all statistically significant (P<0.05) except for the palatal plane inclination in Class III patients (P>0.05). There was a significant difference in the gonial angle of Class II patients between the right and left sides (P<0.05). The upper incisor vertical index in the right and left sides showed significant differences in all three skeletal classes (P<0.05). The difference between the right and left sides in other angles and skeletal classes was not statistically significant (P>0.05). Conclusion: Skeletal class does not affect the reliability of panoramic radiographs for angular measurements, except for the palatal plane inclination in Class III patients.
