Acta odontologica latinoamericana : AOL最新文献

The aim of the present study was to evaluate the presence of maxillary first and second molars with a C-shaped canal system in an Argentine subpopulation, and to classify them.

Materials and method: Of the 332 CBCTs initially evaluated, 120 met the selection criteria. Once the presence of a C-shaped canal system had been established, the teeth were classified following Martins et al. Data were expressed as absolute frequencies, percentages with of 95% confidence intervals, according to the score test. Comparisons were analyzed by Chi-square test and Fisher' exact test, with 5% significance level.

Results: It was found that 5 out of 120 first molars (4%) and 17 out of 152 second molars (11%) had a C-shaped canal system. Regarding the classification applied, of 5 C-shaped first molars, 2 corresponded to type E2 (40%), 2 corresponded to type C (40%), and 1 corresponded to type B1 (20%). Of 17 C-shaped second molars, 4 resembled a type A (24%), 7 resembled a type B1 (41%), 5 resembled a type B2 (29%), and 1 resembled a type C (6%). UC1 and UC2 configurations were the most common at all levels except apical level.

Conclusion: The prevalence of C-shaped canal system pattern in maxillary first and second molars was estimated for the first time in an Argentine subpopulation, in vivo. Knowledge of these data should help clinicians during endodontic treatment.

The fact that there are different epidemiological definitions of periodontitis and different evaluation protocols affects the estimate of periodontitis prevalence and of the influence of associated factors. The gold standard for periodontal examination is full-mouth record assessing CAL and PD. However, there are not always sufficient human and financial resources available to apply such assessment for epidemiological surveillance systems.

Aim: This study was conducted to compare different protocols and definitions of periodontitis for assessing prevalence and the impact of related factors in adult patients who requested care at the School of Dentistry, UdelaR.

Materials and method: This was a cross-sectional study of 410 subjects with a high burden of disease in terms of NCDs and periodontitis. Clinical examination evaluated PD in all teeth and CAL in the CPI sextants (WHO 2013). Four periodontitis criteria were defined based on two examination protocols (WHO 2013 and WHO 1997) and two definitions of epidemiological case. Comparisons were made taking the 2013 WHO protocol as a reference.

Results: Comparison of the two examination protocols showed that prevalence was underestimated when the WHO 1997 protocol was used to define moderate-severe and severe periodontitis, by 20% and 60%, respectively.

Conclusions: When the severity of periodontitis was not considered, the WHO 2013 protocol did not provide more information on what factors increase the chance of periodontitis. However, when severity was considered, the associated factors were different. Consequently, in a small population, it would be worth using the WHO 2013 protocol, which is the closest to the full-mouth gold standard criterion.

Various theories have endeavored to explain how knowledge is accessed. Students, in order to learn, need a good repertoire of appropriate metacognitive and self-regulating strategies and knowledge, which they use consciously or unconsciously. Teachers, in addition to knowing how to teach, need to be aware of students' learning strategies, metacognition, and self-regulation, and of the impact of changes associated with recent pandemic scenarios.

Aim: The aim of this study was to identify the study strategies preferred by dental students in two different scenarios: prior to and during the pandemic.

Materials and method: The sample consisted of third-year dentistry students at Buenos Aires University (UBA) during 2019 (Group GP, 141 students, face-toface activity) and 2021 (Group GE, 60 students, e-learning during the pandemic). Participants were asked (a) to provide demographic information (sex and age) and (b) to answer the abridged ACRA scale. Statistical treatment included descriptive tests; Chi2, binomial exact and Student's t-test (p<0.05).

Results: The proportion of students who participated with respect to total students enrolled was 58.50% in 2019 and 26.20% in 2021, with female gender being significantly higher. There were significant differences in total number of participants during the different periods (p=0.001), and in gender distribution during the pandemic (p=0.007). Comparison between groups GP and GE showed no significant difference regarding preferences expressed in total values for the scale or for the domains. Analysis of preferences according to gender showed significant differences in total group (p=0.007) and the domains CLCS (Cognitive and Learning Control Strategies) (p= 0.008) and LSS (Learning Support Strategies) (p=0.002). The mean values of preferences selected by females were higher. Similar results were found upon analyzing preferences during the pandemic (n= 60) considering total score (p= 0.033) and the domains CLCS (p= 0.035) and LSS (p= 0.007).

Conclusions: The study identified trends towards an increase in the score and consequently greater use of techniques included in the domains related to metacognition, especially among women. There is potential neutralization of the impact created by the methodological shift between the two periods (face-to-face and e-learning) probably as a result of the implicit adaptability, latent in students, regarding digital methodology, which enables them to adapt to learning in challenging situations.

Eighth-generation adhesives may be applied with total etch, selective-etch or self-conditioning, and serve as primers for non-dental substrates.

Aim: To determine the bonding characteristics of universal adhesives applied to the deep pulp wall with different strategies, by means of shear bond strength and laser microscopy.

Materials and method: Cavities 4 mm deep and maximum width were carved in 36 extracted molars. Nine groups were formed according to dental substrate treatment and adhesives, as follows: Total-etch: group 1-Monobond 7 self-etch, group 2-One coat 7 universal, and group 3-Single bond universal; Adamantine etch: group 4-Monobond 7 self-etch, group 5-One coat 7 universal, and group 6-Single bond universal; Self-conditioning: group 7-Monobond 7 self-etch, group 8-One coat 7 universal, and group 9-Single bond universal. Molars were filled following the manufacturer's instructions. Three specimens per group (27 altogether) were used to determine shear bond strength using a universal testing machine, while layer thicknesses were measured on the remaining specimens using microscope images and Olympus LEXT 3D Software. Analysis of variance was used to compare data.

Results: Mean (standard deviation) bond strength in megapascals (MPa) was: group 1: 7.06±3.01; group 2: 10.74±4.36; group 3: 8.20±3.92; group 4: 7.41±2.23; group 5: 6.84±1.50; group 6: 5.86±2.10; group 7: 5.83±1.94; group 8: 7.14±2.37; group 9: 8.06±3.51. Bond strength was higher (p=0.049) for total-etch (8.61±3.96) than for selective etch (6.71±1.98) and self-conditioning (6.91±2.68). No significant difference was found among the three adhesives (p=0.205). Adhesive layer in micrometers (μm) was total-etch 8.71±4.93, selective etch 5.49±1.70 and self-conditioning 6.27±3.01, with no significant difference.

Conclusions: There were significant differences among bonding strategies, with the highest values for total-etch. No significant difference was observed between self-conditioning and selective etch. No significant difference was found among the adhesives, which all behaved similarly. The greatest adhesive layer thicknesses were recorded in the total-etch group, with no significant difference among the various adhesive approaches.

The objective of this study was to evaluate the microtensile bond strength (μTBS) to dentin of two universal adhesive systems: Single Bond Universal (SBU) and Ambar Universal (AU), used in different adhesion strategies.

Materials and method: Thirty-six human teeth were prepared (n=6) and treated following different adhesive strategies: G1: SBU-etch-and-rinse, applied on dry dentin; G2: SBUetch- and-rinse, applied on moist dentin; G3: SBU-self-etching; G4: AU-etch-and-rinse, applied on dry dentin; G5: AU-etch-and-rinse, applied on moist dentin; G6: AU-self-etching. The specimens were submitted to μTBS test, failure analysis, and scanning electron microscopy (SEM). Data were analyzed with ANOVA and Tukey's tests (p<0.05).

Results: Microtensile bond strength was significantly lower in G1 than G2 and G3. AU adhesive performed worse than the SBU system, except in G5. Cohesive and mixed failures predominated in G1 and G2, while adhesive failures predominated in G3 and G5.

Conclusions: Universal adhesives are an interesting innovation, but there are still doubts about their performance, mainly regarding the different protocols provided by the manufacturers. The conventional adhesive strategy on moist dentin demonstrated higher μTBS for both adhesives. The use of the selfetching strategy with the SBU showed promising results.

Identifying factors that influence the satisfaction of undergraduate dental students can contribute to establishing strategies for improving the educational process, furthering student development, and enhancing students' academic and professional achievements.

Aim: the present study investigated associations between undergraduate students' satisfaction with the dental course and their satisfaction with life, perception of professional career and sociodemographic factors.

Materials and method: this was a cross-sectional study on 512 dental students from a Brazilian School of Dentistry. Students were asked to respond to three questionnaires about sociodemographic characteristics, academic, and professional perceptions. Satisfaction with life was measured using the Brazilian version of the Satisfaction with Life Scale, which comprises five statements with responses scored on a seven-point Likert scale ranging from "I strongly disagree" to "I strongly agree". Unadjusted and adjusted multiple logistic regression analyses were performed to test associations between satisfaction with the dental course and key variables.

Results: most participants were female (73.2%), single (99.8%) and with mean age 21.77 (±2.71) years. Approximately three quarters had a family income over three times higher than the national monthly minimum wage. Higher satisfaction with the course was associated with more optimistic perception of the job market (OR=2.44; 95% CI: 1.36-4.40), better academic performance (OR=1.65; 95% CI: 1.00-2.74) and greater satisfaction with life (OR=1.10; 95% CI: 1.06-1.15). Students' sex and family income did not have significant impact on satisfaction with the dental course.

Conclusions: satisfaction with the dental course is related to an optimistic perception of the job market, academic performance and satisfaction with life.

Orthodontic appliances promote the accumulation of biofilm in the oral cavity and increase counts of Streptococcus mutans (S. mutans). However, there are few comparative studies of the effects generated by the interaction of saliva and microorganisms in absence and presence of orthodontic appliances.

Aim: The aim of this study was to determine the S. mutans colony-forming unit count (CFU/mL) in participants with and without fixed orthodontic appliances.

Materials and method: It was an observational cross-sectional study on 21 participants, all over 18 years of age, non-smokers, without removable oral appliances, who had not been under antibiotic treatment within the previous three months. Sociodemographic variables, oral hygiene habits, S. mutans CFU/mL count, and salivary pH were assessed. Saliva samples were collected, and the data was analyzed using Fisher's exact and Kruskal Wallis tests. A p-value <0.05 was considered statistically significant.

Results: Fourteen (66.7%) of the participants were female; average age was 20.4 ± 2.2 years. The group without fixed orthodontic appliances had the highest salivary S. mutans CFU/mL count (Me: 56.0×103, IQR: 9.2×103 - 75.5×103), but there was no statistically significant difference between groups (p=0.7459). There was a statistically significant difference in salivary pH, with the metal orthodontic appliance group having the lowest pH (p=0.0478). No statistically significant difference in salivary S. mutans CFU/mL count was found between groups. Salivary pH was lower in the group with metal appliances than in the groups with non-metal appliances and without appliances.

Aim: This study investigated how Colombian dentists with different academic levels indicate antibiotics with therapeutic purposes in endodontics.

Materials and method: A cross-sectional survey was conducted among 559 dentists in the form of an online questionnaire.

Results: Three hundred and twenty questionnaires were answered (57.2%). There were significant differences among respondents. For irreversible pulpitis, 140 dentists (43.7%) said they prescribe antibiotics (57.5% of general practitioners, 20.1% of specialists and 38.9% of those with Master's and/or PhD degrees), while for symptomatic apical periodontitis, 183 (57.2%) did so (74.1% of general practitioners, 28.4% of specialists and 50.0% of those with Master's and/or PhD degrees) (p<0.05). Amoxicillin was the most frequently prescribed antibiotic, and its association with clavulanic acid was the most often cited for acute periradicular abscess with systemic involvement.

Conclusions: The greatest misunderstandings in prescribing antibiotics occurred among general practitioners. Considering all clinical conditions that do not require antibiotics, 60% of general practitioners and 34% of specialists, on average, indicated antibiotics.

The aim of this study was to evaluate tooth color in dental students at the University of Buenos Aires, Argentina. The participants were 184 students (157 women and 27 men) aged 21 to 33 years, mean age 24.45 (SD 2.79) years, who were in the fourth year of their dental degree. They agreed to participate through an informed consent. Exclusion criteria were: having undergone a bleaching treatment within the previous six months, presence of total or partial peripheral restoration, pigmentations, fracture, carious and non-carious lesions or absence of the right upper central incisor (1.1). A dental prophylaxis procedure was performed on the buccal surface of each 1.1 tooth with a prophylaxis brush (TDV) mounted on a low-speed rotary instrument Kavo 2068 CHC (Germany) micromotor and a Kavo LUX K201(Germany) contra-angle. Shade was measured in the middle third of each 1.1 tooth, by the same observer, using a VITA Easyshade V spectrophotometer (Zahnfabrikn Bad Säckingen, Germany), which was calibrated before each determination according to manufacturer's instructions, in the same dental unit (Sino S2316), with natural illumination, in the same time slot, without using the dental unit lamp. The results were recorded in an ad-hoc form and rates and confidence interval were obtained. Shade prevalence percentages (95% CI) were: A1: 46.2 (38.83 - 53.68); followed by A2 and B2, both with 17.39 (12.21 - 23.66); A3: 6.52 (3.41-11.11); B1: 4.35 (1.9-8.39); D2: 2.72 (0.89 - 6.23); B3: 2.17 (0.60-5.47) and C2: 1.09 (0.13-3.87); D3, C3, A3.5 and A4: 0.54 (0.01-2.99). Shades D1 and C1 were not determined in any subject. Within the conditions of this study, A1 was the most prevalent shade in central incisors, followed by A2 and B2.

Odontoblasts and gingival fibroblasts play essential roles in the physiological and pathological processes of dental tissue. Cannabinoid receptors (CB1 and CB2) are involved in analgesia by modulating the función of calcium channels that inhibit the synthesis of some neurotransmitters. A better understanding of the physiology of these receptors would provide the possibility of using them as therapeutic targets in controlling dental pain. The aim of this study was to evaluate the presence and activity of cannabinoid receptors in human odontoblast-like cells (OLC) and human gingival fibroblasts (HGF). CB1 and CB2 transcription was analyzed by real-time PCR, proteins were detected by immunofluorescence, and functional cannabinoid receptors were evaluated by measuring intracellular calcium concentration after stimulation with cannabidiol (CBD) and pre-treatment with a CB1 antagonist, a CB2 inverse agonist and a TRPV1 antagonist. Transcripts for CB1 and CB2 were found in both odontoblasts and gingival fibroblasts. Cannabidiol induced an increase in [Ca2+]i in both cells types, but surprisingly, pre-treatment with selective cannabinoid antagonists attenuated this effect, suggesting a functional communication between specific cannabinoid receptors and other CBD target receptors. In conclusion, human odontoblasts and gingival fibroblasts express functional CB1 and CB2 cannabinoid receptors, which could be modulated to improve the treatment of pain or dental sensitivity.