ABSTRACT
Objectives@#This study investigated the incidence of root dentin defects after the use of different post space preparation (PSP) drills. @*Materials and Methods@#Seventy-two bovine incisors were selected and obtained 14-mmlong root sections. Twelve roots served as controls with no intervention (G1). The 60 root canals remaining were instrumented using the crown-down technique with the ProTaper Next system and obturated using the lateral condensation technique. Specimens were randomly distributed into 5 groups (n = 12) according to the operative steps performed: G2, root canal instrumentation and filling (I+F); G3, I+F and PSP with Gates-Glidden drills; G4, I+F and PSP with Largo-Peeso reamers; G5, I+F and PSP with Exacto drill; and G6, I+F and PSP with WhitePost drill. Roots were sectioned at 3, 6, 9, and 12 mm from the apex, and digital images were captured. The presence of root dentin defects was recorded. Data were analyzed by the χ2 test, with p < 0.05 considered to indicate statistical significance. @*Results@#Root dentin defects were observed in 39.6% of the root sections. No defects were observed in G1. G5 had significantly more cracks and craze lines than G1, G2, and G3 (p < 0.05), and more fractures than G1, G2, G3, and G4 (p< 0.05). When all root sections were analyzed together, significantly more defects were observed at the 12-mm level than at the 3-mm level (p < 0.05). @*Conclusions@#PSP drills caused defects in the root dentin. Gates-Glidden drills caused fewer root defects than Largo-Peeso reamers and Exacto drills.
ABSTRACT
Objectives@#This study investigated the incidence of root dentin defects after the use of different post space preparation (PSP) drills. @*Materials and Methods@#Seventy-two bovine incisors were selected and obtained 14-mmlong root sections. Twelve roots served as controls with no intervention (G1). The 60 root canals remaining were instrumented using the crown-down technique with the ProTaper Next system and obturated using the lateral condensation technique. Specimens were randomly distributed into 5 groups (n = 12) according to the operative steps performed: G2, root canal instrumentation and filling (I+F); G3, I+F and PSP with Gates-Glidden drills; G4, I+F and PSP with Largo-Peeso reamers; G5, I+F and PSP with Exacto drill; and G6, I+F and PSP with WhitePost drill. Roots were sectioned at 3, 6, 9, and 12 mm from the apex, and digital images were captured. The presence of root dentin defects was recorded. Data were analyzed by the χ2 test, with p < 0.05 considered to indicate statistical significance. @*Results@#Root dentin defects were observed in 39.6% of the root sections. No defects were observed in G1. G5 had significantly more cracks and craze lines than G1, G2, and G3 (p < 0.05), and more fractures than G1, G2, G3, and G4 (p< 0.05). When all root sections were analyzed together, significantly more defects were observed at the 12-mm level than at the 3-mm level (p < 0.05). @*Conclusions@#PSP drills caused defects in the root dentin. Gates-Glidden drills caused fewer root defects than Largo-Peeso reamers and Exacto drills.
ABSTRACT
Statement of the Problem: Mucous retention cysts [MRCs] of the maxillary sinus are lesions with undefined pathogenesis. In recent researches, geographical and climatic aspects have been related as risk factors
Purpose: The purpose of this study was to determine the frequency of MRCs of the maxillary sinus using panoramic radiographs
Materials and Method: A total of 631 panoramic radiographs were selected from a secondary database from a private radiology clinic and analyzed by two specialists in dental radiology according to gender, age, month, relative air humidity, and mean temperature
Results: A total of 87 [6.89%] radiographic images were suggestive of MRCs. Thirty-five MRCs [40.22%] were detected on the right side, 10 [11.49%] on the left side and 42 [48.29%] on both sides. A high frequency was detected in female participants [n=45; 51, 72%], those aged 18-35 years [n=31; 35, 63%] and those from August [n=24; 27.59%] and July [n=22; 25.29%]
Conclusion: The frequency of MRCs was low, and no statistically significant correlation was found between the prevalence of MRCs and the studied variables with the exception of the mean temperature
ABSTRACT
OBJECTIVES: This study evaluated the solubility, dimensional alteration, pH, electrical conductivity, and radiopacity of root perforation sealer materials. MATERIALS AND METHODS: For the pH test, the samples were immersed in distilled water for different periods of time. Then, the samples were retained in plastic recipients, and the electrical conductivity of the solution was measured. The solubility, dimensional alteration, and radiopacity properties were evaluated according to Specification No. 57 of the American National Standards Institute/American Dental Association (ANSI/ADA). Statistical analyses were carried out using analysis of variance (ANOVA) and Tukey's test at a significance level of 5%. When the sample distribution was not normal, a nonparametric ANOVA was performed with a Kruskal-Wallis test (alpha = 0.05). RESULTS: The results showed that white structural Portland cement (PC) had the highest solubility, while mineral trioxide aggregate (MTA)-based cements, ProRoot MTA (Dentsply-Tulsa Dental) and MTA BIO (Angelus Ind. Prod.), had the lowest values. MTA BIO showed the lowest dimensional alteration values and white PC presented the highest values. No differences among the tested materials were observed in the the pH and electrical conductivity analyses. Only the MTA-based cements met the ANSI/ADA recommendations regarding radiopacity, overcoming the three steps of the aluminum step wedge. CONCLUSIONS: On the basis of these results, we concluded that the values of solubility and dimensional alteration of the materials were in accordance with the ANSI/ADA specifications. PCs did not fulfill the ANSI/ADA requirements regarding radiopacity. No differences were observed among the materials with respect to the pH and electrical conductivity analyses.