Acta odontologica latinoamericana : AOL最新文献

Cannabinoid receptors (CBr) 1 and 2 (CB1r and CB2r) are present in periodontal tissues and salivary glands and play a significant role in the pathogenesis of oral diseases.

Aim: To study the gene expression of CB1r and CB2r in gingival tissue and submandibular glands (SMG) of rats subjected to experimental periodontitis (EP) and/or hyposalivation (H), and discuss their possible implication in oral health.

Material and methods: Rats were divided into controls, rats with EP induced by application of lipopolysaccharide (1 mg/ml), rats with H induced by bilateral submandibulectomy, and rats with both EP and H. Alveolar bone loss was measured with a digital caliper, mRNA expression of CBr and bone parameters were determined by endpoint RT-PCR, PGE2 glandular content was assessed by radioimmunoassay, and stimulated salivary secretion was collected and weighed.

Results: CB1r and CB2r mRNA in gingival tissue were upregulated in groups EP, H and EP+H as compared to controls (CB1r (AU): C 0.27±0.06A, EP 0.46±0.05B, H 0.51±0.08B, EP+H 0,49±0,1B; CB2r (AU): C 0.38±0.04A, EP 1.22±0.08B, H 0.98±0.06C, EP+H 1,041±0,1BC). Groups EP, H and EP+H showed alveolar bone loss as opposed to controls, while only groups EP and EP+H evidenced RANKL/OPG imbalance measured in the dental attachment tissue. Likewise, CB1r and CB2r mRNA in SMG showed upregulation in group EP as compared to controls (CB1r (AU): C 0.52±0.09A, EP 0.95±0.13B; CB2 (AU): C 0.23±0.12A, EP 1.48±0.22B). In group EP, salivary secretion was lower and the content of PGE2 (inhibitory mediator of said function) was higher than in controls.

Conclusion: The upregulation of CB2r in oral tissues under the pathophysiological conditions studied suggests that they participate actively in the response to oral diseases.

Given the limitations of the intrarradicular adhesion procedure and the significant challenge of achieving effective bonding, it is essential to assess the potential impact of various endodontic sealers on the bond strength between fiberglass posts and root dentin.

Aim: The aim of this study was to evaluate the bond strength of fiberglass posts to the root dentin of teeth filled with different endodontic sealers.

Material and methods: Forty-five single-rooted teeth were instrumented, filled using the single-cone technique, and divided into three groups according to the selected sealer (n=15): Bio-C sealer (GBC), AH Plus (GAH), and control group without sealer (GC). The post was installed using RelyX U200 self-adhesive resin sealer. Specimens were cut into a cervical, middle and apical thirds, to analyze one slice per third. Bond strength was evaluated using a push-out extrusion test. The failure modes in each third were observed under the microscope, and classified as adhesive, cohesive or mixed.

Results: It was found a difference between groups in the cervical and apical thirds, with GAH having stronger adhesion in the cervical third than GBC (p=0.0015), although there was no difference with GC. In the apical third, GAH had higher adhesion values than GBC (p=0.0014) and GC (p=0.0005). In the middle third, there was no difference between groups (p=0.1386). The same sealer in the different thirds only differed significantly in the GBC group, where bond strength was higher in the middle and apical thirds, with a significant difference from the cervical third (p<0.05). There was no difference between failure types in any of the groups (p>0.05).

Conclusion: The predominant failure between dentin and sealer was adhesive. It was concluded that the use of AH Plus endodontic sealer resulted in less impairment of the bond strength of resin cemented fiberglass posts compared to bioceramic sealer.

Around the world it is considered good practice to provide patients with a postoperative instruction and advice leaflet following tooth extractions. It has never been reported whether the design or the content is effective or helpful for a patient's recovery.

Aim: To assess the opinions of patients about two postoperative instructions leaflets with similar content but different designs.

Materials and method: A questionnaire was administered to 32 patients who had recently undergone oral surgery. The questionnaire asked patients about their satisfaction with the information and their overall opinion of two postoperative leaflet designs (a conventional and a daily planner design).

Results: 53% of the patients preferred the daily planner design and 6.3% preferred the conventional model. 60% of the patients recommended the daily-planner leaflet for future patients.

Conclusion: The results of this study suggest that patients find postoperative instructions leaflets to be helpful because they can help to guide patient to follow instructions after surgery. The daily planner was preferred because it was easy to review every day during recovery.

Dentine wall thickness in the mesial roots of molars is critical to prevent root stripping. Understanding the effect of rotatory instruments on the second mesiobuccal canal is crucial to prevent weakening and periodontal communication.

Aim: To evaluate the effect of different conservative tapered mechanized instrumentation systems on the distal wall thickness of the second mesiobuccal canal of maxillary first molars in 3D dental replicas.

Materials and method: Fifty radiopaque 3D printed replicas were made of a maxillary first molar with Vertucci classification IV and Schneider curvature (<10°), 23 mm in length. The specimens were divided into 5 groups of 10. In all cases, the second mesiobuccal canal was instrumented to the working length. Group 1 was instrumented with Race Evo (FKG) up to file 30/04, Group 2 with AF F One (Fanta-Dental) up to file 35/04, Group 3 with Slim Shaper (Zarc4Endo) up to file 30/04, and Group 4 with Trunatomy, while the control group was not instrumented. Distal wall thicknesses were measured in the cervical, middle and apical thirds by CBCT before and after instrumentation. Descriptive statistics were calculated, after which analysis of variance and Tukey's test for multiple comparisons were performed (p < 0.05).

Results: Analysis of variance showed a significant effect of instrumented group and thirds (p < 0.001). The multiple comparison test showed that the control and Race Evo groups differed significantly from the other three groups. Within each group, the differences between thirds were statistically significant.

Conclusion: Trunatomy, Slim Shaper and Fanta AF One systems are suitable for shaping second mesiobuccal canals while maintaining critical distal wall thickness.

Aim: We evaluated various oral features related to the smile among Vietnamese students. Additionally, we identified gender differences in the oral features and the prevalence of attractive smiles.

Materials and method: We recruited 490 Vietnamese students with 18-29 years old and recorded their dynamic smiles. We determined the prevalence of the qualitative smile morphological features and the mean and standard deviation of the quantitative features, namely the buccal corridor space, the smile index, and dynamic smile symmetry.

Results: There were diverse smile-related oral characteristics among the participants. The most common anterior smile line was "average" (42.6%), and "parallel" was the most prevalent smile arc (43.1%). We observed a "downward" upper lip curvature in 55.9% of the participants, and the "second premolar" was the most frequently displayed posterior tooth (58.6%). Most of the participants (79.2%) showed no contact between the upper teeth and the lower lip while smiling. The mean buccal corridor space was 0.59 ± 0.47 cm, the smile index was 5.85 ± 1.48, and dynamic smile symmetry was 1.01 ± 0.06. There were significant gender differences for several smile related characteristics.

Conclusions: Women more often display a favorable smile arc and more teeth when smiling, while men are more likely to have an attractive anterior smile line and upper lip curvature. These insights are vital to tailor effective aesthetic treatments.

The new classification system of periodontal diseases, introduced in 2017, aims to provide more precise diagnostic criteria for identifying and classifying periodontitis. It defines periodontal disease based on staging, grading and extent, facilitating a more accurate approach for general dentists and periodontists.

Aim: The aim of this study was to establish the inter-observer agreement and diagnostic accuracy among three groups with different levels of education and experience in dentistry in assigning stages, grades and extent of periodontitis using the 2017 AAP-EFP classification system.

Materials and method: The study involved 32 participants divided into three groups: Group 1-dental students (n=12), Group 2-dentists with up to 3 years' experience (n=10), and Group 3-general dentists with more than 4 years' clinical experience (n=10). Twelve periodontitis cases were evaluated by all participants, who classified each case by stage, grade and extent. The evaluations were compared with the gold standard provided by a panel of expert periodontists. Statistical analysis, including Fleiss' kappa and chi-square tests, was performed to assess agreement and diagnostic accuracy.

Results: Significant differences were observed in stage classification, with students and recent graduates more likely to underestimate the severity of the disease, while experienced dentists tended to overestimate it. No significant differences were found in grade and extent classifications. Diagnostic accuracy was comparable across all groups, but students showed slightly higher agreement with the gold standard compared to other groups.

Conclusions: The 2017 AAP-EFP classification system can be applied by both general dentists and dental students, but further clinical practice is needed to improve diagnostic accuracy. Misclassification tendencies, such as over- or underestimation of disease severity, highlight the need for additional training and familiarity with the system.

Several instrumentations systems are available in the market and it is necessary to assess their behavior in curved root canals.

Aim: To analyze the ability of two manual instrumentation techniques to center mesial root canals of mandibular molars, studied by computed microtomography (micro-CT).

Materials and method: Twenty mesial root canals of mandibular molars were matched based on similar morphological dimensions using micro-CT evaluation and divided in 2 groups (n=10): (1) Crown-down technique with Gates-Glidden drills and K-Flexofiles and (2) M manual NiTi rotary system. Changes in volume, surface area and canal transportation were compared using an unpaired t-test with a 5% significance level.

Results: No significant differences were observed between groups regarding volume surface area after root canal preparation (p>0.05). Variation in the centroid differed between groups in the total canal length, and in the cervical and middle thirds, with better centralization for the M files (p<0.05).

Conclusions: Both manual instrumentation techniques had similar volume and surface area variation. Both techniques left unprepared canal areas with similar values. M manual NiTi files caused minor canal transportation.

Complete removal of the filling material is essential to the success of endodontic retreatment. However, this step can be challenging due to anatomical difficulties, the nature of the sealer, or operational factors.

Aim: To evaluate the efficacy of filling removal using ProDesign R and Reciproc Blue retreatment, with supplementary irrigation step with XP-Endo Finisher R.

Materials and method: Twenty mandibular molar mesial canals were prepared using ProTaper Next, and filled using the single-cone technique (n=10). The fillings were subsequently removed using either ProDesign R (25/0.06) or Reciproc Blue (25/0.08 in the 3 mm from the tip of the file, decreasing towards the cervical, with average taper varying from 0.06 to 0.05 along the instrument). The XP-Endo Finisher R system was used for supplementary cleaning for both systems. Micro-computed tomography was used to assess filling material volume and reduction percentage. The significance level was set at 5% (p< 0.05).

Results: It was found that ProDesign R and Reciproc Blue removed 91.2% and 82.7% of the filling material, respectively (p > 0.05), and after use of XP-Endo Finisher R, there was a significant increase in filling removal by 42.7 and 27.7%, respectively.

Conclusion: ProDesign R and Reciproc Blue were equally effective, but neither system completely removed the filling material from the mesial canals of mandibular molars.

The evaluation of oral health services is an essential component of surveillance efforts aimed at improving health indicators and the quality of care.

Aim: The aim of this cross-sectional study was to describe the characteristics of the oral healthcare work process in primary care settings in Porto Alegre, a major city in southern Brazil.

Materials and method: Data on patient profiles and process evaluation components were provided by the Porto Alegre Primary Healthcare Board. An electronic questionnaire was administered to dentists to assess the structure components. Data were classified into three modules: patient profile (sex and age), structure (human resources), and process (actions and procedures). Descriptive statistical analyses were conducted, including the calculation of absolute and relative frequencies.

Results: In 2022, a total 414,682 dental appointments were recorded, the majority involving women and individuals aged 35-59 years. Most dentists were young women, primarily specialized in collective health. The process analysis highlighted a strong focus on preventive and health promotion actions, although fluoride applications, sealants, and cariostatic agents were underutilized. Composite resin restorations in permanent teeth were common. Dental emergencies accounted for 17% of cases, and 95% of surgical procedures consisted of extractions and sutures. Additionally, dentists performed integrative practices and other activities, such as rapid testing and vital sign measurements, particularly in response to the COVID-19 pandemic.

Conclusions: The findings of this study are intended to inform strategies and service management aimed at improving oral health care in the primary care setting of Porto Alegre.

Micro-screw stability requires adequate bone quantity and quality. Micro-screws are often placed inthe hard palate, in which anatomy may vary according to vertical growth.

Aim: To compare the height,width and density of the palate according to facial biotype using cone beam computed tomography(CBCT).

Materials and method: Observational cross-sectional study on a sample of 39 CBCT scansof adults aged 18 to 50 years (19 females and 20 males) assigned to facial biotypes according to SNGoGn. The height (mm), cortical width (mm) and density in Hounsfield units (HU) were measured at 20coordinates on the left side of the palate coordinates corresponding to the combinations of four pointsmedial to the suture (3, 5, 7 and 9 mm) and five points posterior to the incisive foramen (3, 6, 9, 12 and15 mm). ANOVA and Kruskal-Wallis tests were used for statistical analysis at a significance level of p< 0.05.

Results: Values were: hypodivergent (height: 2.16 - 6.32 mm; width: 1.61 - 2.02 mm; density:1117.28 - 1182.83 HU), normodivergent (height: 2.71 - 9.21 mm; width: 1.67 - 2.08 mm; density:1106.53 - 1177.86 HU) and hyperdivergent (height: 2.37 - 12.32 mm; width: 1.62 - 2.07 mm; density:1088.2 - 1156.7 HU). Compared to hyperdivergent subjects, in hypodivergent individuals 60% of themeasurement points had lower heights and 15% of measurement points showed thinner, denser cortices,with significant differences (p <0.05).

Conclusion: Facial biotypes were found to be associated withpalate bone characteristics, with greater cortical heights and widths in hyperdivergent subjects andgreater densities in hypodivergent subjects.