PURPOSE: This study aimed to investigate the clinical anatomy of lower premolar roots in a Spanish population by using cone-beam computed tomography (CBCT), correlating findings with patient gender and tooth type. MATERIALS AND METHODS: Using 70 CBCT images, we evaluated 126 healthy, untreated, well-developed lower premolars. The number and morphology of roots and root canals, and the foramina number were assessed. Results for gender and tooth type were compared using the chi-squared and ANOVA tests. RESULTS: The average length of teeth and roots was significantly higher in men (p=0.00). All 126 premolars had a single root. One canal was found in 83.3% of the premolars, with no gender or tooth type differences; Vertucci configuration types I and V were the most prevalent. The first premolars showed significantly greater variability than the second premolars (p=0.03). A single apical foramen was found in 89.7% of the premolars, with no differences by tooth type. Women had a significantly higher prevalence of two apical foramina than men (p=0.04). Some degree of curvature was observed in 65% of the premolars, with no differences by gender or tooth type. A root angle of more than 20degrees was found in 12.98% of the premolars, without any differences by gender or tooth. CONCLUSION: All premolars were single-rooted. One canal had the most prevalent morphology. More variability in canal anatomy was found in the first premolars. Curvatures greater than 20degrees were found at less than 5 mm from the apex.
Anatomy, Regional ; Bicuspid* ; Cone-Beam Computed Tomography* ; Dental Pulp Cavity ; Female ; Humans ; Male ; Mandible ; Prevalence ; Tooth ; Tooth Apex

OBJECTIVES: This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl), 2% chlorhexidine (Group B, CHX) and saline solution (Group C, control group) were applied with Irrisafe 20 tips (Acteon) and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM). The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. RESULTS: In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05), but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. CONCLUSIONS: NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.
Chlorhexidine ; Dentin ; Humans ; Microscopy, Confocal ; Rhodamines ; Sodium Chloride ; Sodium Hypochlorite ; Tooth ; Ultrasonics*

OBJECTIVES: This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl), 2% chlorhexidine (Group B, CHX) and saline solution (Group C, control group) were applied with Irrisafe 20 tips (Acteon) and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM). The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. RESULTS: In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05), but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. CONCLUSIONS: NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.
Chlorhexidine ; Dentin ; Humans ; Microscopy, Confocal ; Rhodamines ; Sodium Chloride ; Sodium Hypochlorite ; Tooth ; Ultrasonics*