Journal of Clinical and Experimental Dentistry最新文献

Inverted ductal papilloma is an uncommon benign papillary endophytic tumor. This report aimed to present a case of inverted ductal papilloma of the oral cavity. A 54-year-old female patient presented with an asymptomatic nodular lesion on the lower lip. Time of duration was undetermined. The diagnostic hypotheses were fibrous hyperplasia and benign mesenchymal neoplasm. An excisional biopsy was performed, and microscopic examination showed an endophytic proliferation of squamous cells with the presence of microcysts, and goblet cells arranged in nest and islands. No cellular atypia was observed. The neoplastic cells were positive for CK7, and CK14. Proliferation index, demonstrated by Ki-67, was positively restricted to the basal tumor layer. The final diagnosis was oral inverted ductal papilloma. No signs of recurrence were found after surgery. Key words:Inverted papilloma, intraductal papilloma, oral papilloma.

Background: Root canal shaping is an important phase in endodontic treatment to preserve the integrity of root structures. This clinical study used cone-beam computed tomography (CBCT) to assess the shaping ability of Tornado compared to WaveOne (WO), and OneShape (OS) rotary systems.

Material and methods: MesioBuccal canals of lower molars with curving angles ranging from 15° to 45° were used in 30 patients to evaluate the apical transportation and centering ability of Tornado, WO, and OS. The canals were divided into 3 groups according to the instrumentation system (n=10), which corresponded to the systems that were employed. Centering ratio and canal transportation were assessed at 2, 5, and 8 mm from the apical foramen using CBCT. Statistical analysis was conducted using the Kruskal-Wallis test and Mann-Whitney test at p-value = 0.05.

Results: All tested levels showed no statistically significant difference in transportation and centering ability (P>0.05). The Tornado file preserved the original canal curvature with no statistical significance compared to WO files and OS.

Conclusions: The tornado file system was proven to provide an accepted quality of root canal shaping compared to WO and OS rotary systems. All systems maintained the original canal anatomy with appropriate centralization and no canal transportation. Key words:Canal Centering Ability, Canal Transportation, Cone-beam Computed Tomography, Nickel-Titanium Files, Tornado Rotary System.

Background: Mandibular asymmetry is more common than previously thought. The purpose of this study was to determine the prevalence of mandibular, condylar and ramus asymmetry by means of the Habets index using panoramic radiographs obtained from adult individuals.

Material and methods: This cross-sectional study evaluated 210 panoramic radiographs performed in adults attending a private referral radiology center in Lima, Peru. Radiographs of both genders were considered, including permanent dentition and of good quality. A trained and calibrated evaluator assessed mandibular, condyle and ramus height using the Habets method, considering asymmetry when the difference between the two sides was greater than 3%. Fisher's exact test, the paired Student's t-test and finally binary logistic regression were used to determine the characteristics of the asymmetries.

Results: Mandibular asymmetry was present in 39.5%, condylar asymmetry in 81.4% and mandibular ramus asymmetry in 48.6%, with no differences between genders (P>0.05). Only women showed a difference between the two sides in mandibular (P=0.008), and condylar height (P=0.013), although multivariate analysis showed neither gender nor age to have any significant influence on the occurrence of mandibular, condylar or ramus asymmetries.

Conclusions: The prevalence of mandibular, condylar and ramus asymmetries in the sample evaluated was significant, although most of these asymmetries can be considered mild, given that the highly sensitive Habets index classifies any difference greater than 3% as asymmetry. These asymmetries, although most of them could be clinically not very noticeable, should be considered when planning treatments. In addition, neither gender nor age was found to significantly influence the occurrence of these asymmetries. Key words:Asymmetry, condyle, mandible, orthodontics.

Background: This study aimed to compare rice snail shell nano-hydroxyapatite (nano-HAp) toothpaste combined with basil leaf extract and 1450 ppm fluoridated herbal toothpaste as remineralizing and antibacterial agents.

Material and methods: Experimental toothpastes were prepared with different concentrations of nano-HAp (5% nano-HAp, 10% nano-HAp) and a fixed concentration of basil leaf extract (5% extract). 24 bovine tooth enamel samples were divided into 4 treatment groups. After 6 days of pH cycling, surface microhardness was tested using Vickers Microhardness Test and microporosity was observed using Scanning Electron Microscopy (SEM). The pitting diffusion method was used to test the antibacterial activity of toothpaste against Streptococcus mutans and Lactobacillus acidophilus.

Results: Enamel surface microhardness showed an increase with increasing nano-HAp concentration, while fluoride toothpaste showed the highest level of surface microhardness. Microporosity observation showed the disappearance of microporosity as nano-HAp concentration increased, while fluoride toothpaste still left microporosity. Antibacterial activity of the toothpaste showed that the mean inhibition zone of each group was not significantly different with a very strong inhibition zone.

Conclusions: Rice snail shell nano-HAp toothpaste combined with 5% basil leaf extract is effective as a remineralizing agent by reducing the level of tooth enamel microporosity but cannot match 1450 ppm fluoride toothpaste in increasing surface hardness. In addition, nano-hydroxyapatite toothpaste of paddy field snail shell combined with 5% basil leaf extract is effective as an antibacterial agent for preventing dental caries because it has antibacterial activity equivalent to 1450 ppm fluoride herbal toothpaste. Key words:Nano-hydroxyapatite, basil leaf extract, toothpaste, remineralization, antibacterial.

Background: We aimed to evaluate changes in buccal bone thickness (BBT), buccolingual dental inclinations (BLI), and transversal widths (TW) after treatment using a passive self-ligating system.

Material and methods: Pre- and posttreatment cone-beam computed tomography images (CBCT) of 21 Class I patients (initial mean age: 14.99 ± 1.27 years; initial crowding of at least 4mm) treated without extractions using passive self-ligating appliances were evaluated. Buccal bone thickness, dental inclinations, and transversal widths were measured, and their changes were compared using paired t-test. The associations were assessed using the Pearson correlation coefficient.

Results: BBT showed statistically significant decreases in both arches, mainly for the posterior teeth. Most teeth were proclinated after treatment, with more buccal tipping occurring for the anterior teeth and second premolars in both arches. The results demonstrated significant increases in maxillary and mandibular TW, except for maxillary intercanine distance. Negative correlations between BBT and buccal inclination were observed for the maxillary right lateral incisor, maxillary left second premolar, right mandibular canine, and between BBT and TW for the maxillary left second premolar. A positive association was observed between BBT and TW only for the mandibular right first premolar.

Conclusions: In general, the treatment with passive self-ligating system showed an expansion of the dental arches followed by a decrease in BBT, probably caused by buccal inclination in both arches. Key words:Orthodontic Brackets, Cone-Beam Computed Tomography, Periodontium, Orthodontics.

Background: Previous studies have identified the effects of light curing techniques on both shrinkage strain and contraction stress buildup in composite restorations. Finite Element Analysis (FEA) has several advantages over other experimental methods for evaluating the mechanical properties of direct dental resins. The objective of this systematic review is to assess the impact of light curing protocols on the shrinkage behaviors and other mechanical properties of direct restorative composites utilizing FEA.

Material and methods: The search methodology adhered to the PRISMA guidelines and utilized prominent scientific databases. This systematic review was structured around a question formulated PICO framework. To estimate the methodological rigor of the included studies, a quality assessment tool was utilized.

Results: After the final phase of eligibility evaluation, the systematic review incorporated nine studies. Studies employing FEA primarily aimed to investigate the effects of various light curing protocols on shrinkage behaviors, contraction stress, and microleakage in composite restorations. Most FEA models in these studies incorporated key time-dependent parameters related to composite polymerization, such as shrinkage, Young's modulus, Poisson ratio, and resulting creep. FEA can provide valuable insights into the effects of light curing on the mechanical properties of direct restorative composites, its accuracy, and reliability depend on various factors, including the accuracy of input parameters, modeling assumptions, and validation against experimental data.

Conclusions: The findings underscore the importance of considering various factors such as curing protocol, testing method, composite characteristics, and environmental conditions in understanding, and mitigating the adverse effects of polymerization shrinkage in composite restorations. Key words:Finite Element Analyses, Composite Resins, Light Curing of Dental Resins, Polymerization, Materials Testing, Mechanical Tests.

Background: The purpose of this research was to determine the presence of asymmetry of the mandibular condyle in children aged between 7 and 9 years, with a unilateral posterior crossbite, and compare it with a sample of patients without malocclusion.

Material and methods: The right and left condylar height and width of 401 orthopantomography of children with and without crossbite were measured.

Results: When comparing the height and width of the mandibular condyle in the sample with posterior crossbite we observed that the height and width were almost the same in both condyles. When studying the condylar height in the sample without posterior crossbite, we did not observe differences between both condyles.

Conclusions: The mean condylar height and width in patients with posterior crossbite were higher than that of children without posterior crossbite. This difference was maintained when analyzing the results according to gender and age. Key words:Mandibular condyle, crossbite, orthopantomography, paediatric dentistry, Habets method.

Background: The accessory mental foramen is characterized by small foramina in the surrounding area of the mental foramen with communication with the mandibular canal. The aim of this research was to evaluate epidemiological and radiomorphometric aspects of the accessory mental foramen (AMF) using cone beam computed tomography (CBCT) in Brazilian individuals.

Material and methods: This was a cross-sectional, quantitative, retrospective descriptive study with 250 CBCT scans of dentate individuals in the anterior mandibular region, aged between 18 and 69 years. Presence/absence, linear measurements (length, height, and width), anatomical distances (to the vestibular, lingual, alveolar bone cortices, base of the mandible, and to the apex of the adjacent tooth) were evaluated concerning the accessory mental foramen.

Results: Of the 250 scans, the mean age of the patients was 47.44±12.57 years, with 150 female and 100 male individuals. The total prevalence of AMF was 7.2% (n=18) of cases, with 5.2% (n=13) female individuals and 2% (n=5) male individuals. Bilateral presence of AMF was observed in one case (0.4%). Regarding laterality, AMF presence was observed in 10 cases (4.0%) on the right side and 8 (n=3.2%) on the left side. The mean distance from AMF to the mental foramen was 4.67 mm. The mean horizontal diameter was 1.06mm, and the mean vertical diameter was 0.95mm across the entire sample.

Conclusions: The prevalence of the AMF was 7.2% with 95% confidence intervals (95% CI), showing a slight inclination towards female individuals. Key words:Accessory mental foramen, mental foramen, cone beam computed tomography, anatomical variation.

Background: Glycolic acid (GA) has been tested as enamel and dentin etchant, and final irrigant for smear layer removal. This study evaluated the effects of GA and ultrasonic activation (US) on smear layer removal, dentin penetration, dentin structure and bond strength of the root dentin filling material.

Material and methods: The root canals of 210 teeth were distributed into four test groups: smear layer removal (N=50), dentin penetration (N=50), dentin structure (N=10) and bond strength (N=100). In all tests, specimens were subdivided into five groups, according to the final irrigation protocols: G1:distilled water(DW)+US; G2:17% EDTA; G3:17% GA; G4:17% EDTA+US; G5:17% GA+US. Scanning electronic microscopy, confocal laser scanning microscopy, transmission electronic microscopy and the push-out test were performed to evaluate smear layer removal, dentin penetration, dentin structure and bond strength, respectively. Statistical analysis was performed for each evaluation (α=5%).

Results: Groups 4 (EDTA+US) and 5 (GA+US) were the most effective on smear layer removal, with no statistical differences from each other (p>0.05). The maximum penetration depth into dentinal tubules was observed for group 5(GA+US), being statistically different from all other groups (pp<0.05). Group 5(GA+US) showed the largest collagen dispersion area, being statistically different from groups 1(DW+US), 2(EDTA) and 3(GA) (pp<0.05), and similar to group 4(EDTA+US) (p>0.05). The highest BS values for filling and restorative material were observed for all experimental groups, being statistically different from control group (pp<0.05), with higher predominance of cohesive failure.

Conclusions: The association of GA and US promotes better smear layer removal, dentin penetration and collagen dispersion, with no influence on bond strength of the root dentin filling/restorative material. Key words:EDTA, final irrigation, glycolic acid, ultrasonic activation.