Factors associated with scientific production conditions among dental students from the Peruvian capital: an analysis under a multivariable regression model.

BACKGROUND: The purpose of scientific production is to synthesize and capture research for eventual publication. In Peru, scientific production at the undergraduate level is relatively limited. The purpose of this study was to identify the factors associated with scientific production conditions among dental students from the Peruvian capital. METHODS: This cross-sectional and analytical study evaluated 338 dental students from the Peruvian capital using a questionnaire composed of 15 questions on conditions for scientific production. Pearson's chi-square test and Fisher's exact test were used for bivariate analysis. To evaluate the influential variables, the adjusted Poisson regression model with robust variance using the adjusted prevalence ratio (APR) was employed. The significance level was p < 0.05. RESULTS: A total of 17.8% of the students carried out research studies, while 1.5% published scientific articles. Conditions for scientific production were considered unfavorable in 28.4% of the cases, while 50.6% were classified as somewhat favorable and 21% as favorable. Students who dedicated < 2 h and ≥ 2 h per week to research were 3.04 and 3.84 times more likely to have favourable conditions for scientific production, respectively, compared to those who had no time for it (APR = 3.04, 95% CI: 1.02-9.03 and APR = 3.84, 95% CI: 1.13-13.02; respectively). CONCLUSION: A minority of dental students reported favorable conditions for scientific production. On the other hand, students with more weekly time for research are more likely to have favourable conditions for scientific production compared to those with no time.

Factors associated with the perception of university social responsibility among dental students from two universities in the Peruvian capital: a multivariable regression analysis.

Students play a key role in university social responsibility (USR), as they are the protagonists of change and the fundamental axis in the teaching-learning process. This study aims to assess the factors associated with the perception of university social responsibility among dental students from two universities in the Peruvian capital. This analytical cross-sectional study assessed 754 students from two Peruvian universities between May and July 2023. The study utilized a validated 51-item questionnaire to assess sociodemographic factors and dental students' perception of USR. A Poisson regression model with robust variance and prevalence ratio (PR) was used to assess the influence of variables such as age, sex, marital status, type of university, academic year, and awareness of taking subjects related to USR. The significance was set at p < 0.05. The perception of USR was rated as poor, fair, and good by 16%, 67%, and 17% of the participants, respectively. According to the study, dental students from public universities were 68% more likely to perceive their USR education as poor than those from private universities (APR = 1.68, 95% CI: 1.06-2.66), and those who were aware of taking MSR-related courses were 37% less likely to perceive their USR education as poor (APR = 0.63, 95% CI: 0.40-0.98). Similarly, dental students attending public universities were 2.28 times more likely to perceive poor organizational management in USR compared to their counterparts at private universities (APR = 2.28, 95% CI: 1.51-3.44). Additionally, students in their first and second academic years were 62% and 57% less likely to perceive poor organizational management in USR compared to those in their sixth year (APR = 0.38, 95% CI: 0.19-0.79 and APR = 0.43, 95% CI: 0.20-0.95; respectively). Furthermore, students from public universities were 2.31 times more likely to perceive social participation in USR poorly compared to their counterparts from private universities (APR = 2.31, 95% CI: 1.63-3.26). Lastly, it was observed that students from public universities were 2.51 times more likely to have a poor overall perception of USR compared to students from private universities (APR = 2.51, 95% CI: 1.67-3.78). Acknowledging the diverse contexts and challenges inherent in public and private institutions, it can be concluded that more than half of the dental students had a fair perception of USR. Additionally, attending a public university was found to be a risk factor for having a poor perception of USR. However, taking a course related to USR and being in the early years of the program were identified as protective factors against a poor perception of organizational training and management in USR. It is recommended that students be involved in USR activities, including the Sustainable Development Goals, from the first years of their university education, especially in public universities.

Repeatability and Reproducibility of a Modified Lekholm and Zarb Bone Quality Classification Based on Cone Beam Computed Tomography: An Observatsion Study.

Aim: We propose a modified Lekholm and Zarb classification that considers all possible combinations of cortical and cancellous bone to provide parameters that favor greater repeatability and reproducibility. Materials and Methods: This observational and analytical study consisted of a sample of 50 cone beam computed tomography (CBCT) scans. Two new types (V and VI), three subtypes to type II (II-A, II-B, and II-C), and two subtypes to type III (III-A and III-B) were added to the original bone quality classification. The new types refer to regenerated bone (type V) and bone with some pathology (type VI). The subtypes are described as type II-A: thick cortical surrounding the abundant cancellous bone with sharp trabeculae throughout the image and presence of small and visible medullary spaces; type II-B: thick cortical surrounding the abundant cancellous bone with predominance of diffuse trabeculae in the basal bone and predominant presence of wide and visible medullary spaces; type II-C: thick cortical surrounding the abundant cancellous bone with predominance of very thick and sharp trabeculae in the basal third as well as presence of small and visible medullary spaces; type III-A: thin cortical surrounding the abundant cancellous bone with sharp trabeculae throughout the image and presence of small and visible medullary spaces; type III-B: thin cortical surrounding the abundant cancellous bone with predominance of diffuse trabeculae and presence of diffuse medullary spaces. Five dental specialists were trained in the use of the modified classification and were provided with CBCT-sectioned images of edentulous jaws for classification. Each specialist classified the images twice at a 7-day interval. The strength of intra-examiner and inter-examiner agreement was measured with Cohen's and Fleiss' kappa index, respectively. In addition, the agreement between both classifications was analyzed. All data were analyzed at a 95% confidence level, considering a P-value <0.05. Results: According to the modified Lekholm and Zarb classification, an almost perfect intra-examiner agreement was significant (P < 0.05) in all five specialists, with the kappa index [k] ranging from 0.91 [95% confidence interval (CI): 0.82-0.99) to 0.95 (95% CI: 0.89-1.00). Furthermore, substantial inter-examiner concordance (k=0.76; 95% CI: 0.73-0.79) was significant (P < 0.05). Conclusion: The high repeatability and reproducibility of the modified Lekholm and Zarb classification on CBCT suggest its applicability to distinguish between the various combinations of cortical and cancellous bone and help to define treatment appropriately to optimize results.

Impact of Fear of COVID-19, Depression, Anxiety and Stress on Temporomandibular Disorders in Peruvian Dental Students in the Post-Pandemic Period: A Multivariable Regression Analysis.

Background: Dentists, who frequently encounter potentially infected patients, have experienced significant changes worldwide due to the COVID-19 pandemic. The aim of this study was to evaluate the impact of the fear of COVID-19, depression, anxiety and stress on the presence of temporomandibular disorders (TMD), taking into account possible confounding variables, in Peruvian dental students during the post-pandemic period. Methods: This analytical cross-sectional study assessed 607 Peruvian dental students from two regions of Peru. The study utilized the Depression Anxiety Stress Scales-21 (DASS-21), the Fear of COVID-19 Scale (FCV-19S) and the Short Form of the Fonseca Anamnestic Index (SFAI). Possible confounding variables were sex, age, year of study, marital status, place of origin, area of residence, history of mental illness and living with people vulnerable to COVID-19. For the multivariable analysis, we utilized a Poisson regression model with an adjusted robust variance. The significance level was set at p < 0.05. Results: The rates of depression, anxiety, stress, fear of COVID-19 and temporomandibular disorders were 47.0%, 50.4%, 35.9%, 30.6% and 54.2%, respectively. Moreover, the study revealed that students with depression and anxiety were 38% and 75% more likely to have temporomandibular disorders compared to those without depression (APR = 1.38, 95% CI: 1.15-1.66) and anxiety (APR = 1.75, 95% CI: 1.44-2.13), respectively. Similarly, the likelihood of presenting temporomandibular disorders was 55% higher in women than in men (APR = 1.55, 95% CI: 1.28-1.87). Furthermore, we found that stress and fear of COVID-19 did not determine the development of temporomandibular disorders (p > 0.05). Conclusions: Almost half of the dental students experienced depression, anxiety and TMD in the post-pandemic period. In addition, depression and anxiety were influential factors in the occurrence of TMDs, with the female gender being a risk factor. However, factors such as fear of COVID-19, stress, age, year of study, marital status, place of origin, area of residence, history of mental illness or living with people vulnerable to COVID-19 were not significant.

Importance of local and systemic factors in preventing implant displacement in the mandibular body: a scoping review of existing literature.

BACKGROUND: The aim of this research was to analyse the current literature on displaced dental implants in the mandibular body, including local and systemic variables related to their cause, and to identify the most frequent location. METHODS: The study conducted a search of three databases (Pubmed, Scopus, and Web of Science) using specific index terms such as 'dental implant', 'displacement', 'dislocation', 'displaced', and 'mandible'. The analysis focused on the direction of displacement and the characteristics of the bone tissue (bone quality, density, and quantity) in cases where dental implants were displaced. RESULTS: A total of 371 articles were obtained. Thirteen of these articles were selected and read in full. To define bone quality, the Lekholm and Zarb classification, modified by Rosas et al., was used. The type II-B bone, which is characterized by thick cortical bone surrounding cancellous bone with extremely wide medullary spaces, presented the largest number of complications. Twenty-two cases were found in which the displacement direction was horizontal. Of these, four were displaced vestibularly, fourteen lingually, and four remained in the center. Additionally, 24 cases presented vertical displacement, with 12 displaced towards the inferior border of the mandible, 9 towards the middle or adjacent to the inferior dental nerve canal, and 3 above the inferior dental nerve canal. CONCLUSION: The accidental displacement of implants within the mandibular body is associated with various risk factors, including the characteristics of the bony trabeculum and the size of the medullary spaces. It is reasonable to suggest that only an adequate pre-surgical diagnostic evaluation, with the help of high-resolution tomographic images that allow a previous evaluation of these structures, will help to have better control over the other factors, thus minimizing the risk of displacement.

Antifungal Activity of Morinda citrifolia Methanolic Extract against Candida albicans: An In Vitro Study.

Aim: Natural medicine used as an alternative and/or complementary treatment to counteract diseases is of great importance in public health. Therefore, the purpose of the present study was to assess the in vitro antifungal activity of Morinda citrifolia methanolic extract of peel, pulp, and seed against Candida albicans. Materials and Methods: The present study was experimental in vitro and cross-sectional. Eight replicates were prepared in Sabouraud dextrose agar with five wells each, where 0.12% chlorhexidine, distilled water, and methanolic extract of seed, peel, and pulp of Morinda citrifolia fruit were placed at concentrations of 10,690, 8,270, and 6,430 mg/mL, respectively, to evaluate sensitivity according to Duraffourd's scale. In addition, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined by dilution and agar seeding method. Statistical analysis was performed by analysis of variance (ANOVA) and Tukey's post hoc test, considering a significance level of P < 0.05. Results: The inhibition halos of Morinda citrifolia methanolic extract of seed, peel, and pulp against Candida albicans measured on average 15.94, 11.94, and 11.56 mm, respectively. The MIC of seed, peel, and pulp extract were 1366.25, 2067.5, and 1607.5 mg/mL respectively, whereas the MFC for seed, peel, and pulp extract were 2672.50, 2067.5, and 3215 mg/mL, respectively. Moreover, seed extract presented significantly higher antifungal activity than peel and pulp (P < 0.001). Conclusions: Morinda citrifolia methanolic extract of peel, pulp, and seed showed fungistatic and fungicidal effect against Candida albicans, being this very sensitive to seed extract with a MIC of 1366.25 mg/mL and a MFC of 2672.5 mg/mL, which allows recommending the development of effective pharmacological formulations for the control of candidiasis.

Jawbone quality classification in dental implant planning and placement studies. A scoping review.

Aim: Cone beam computed tomography has become an attractive method for implant planning. However, in most cases, not all the information is taken advantage of and often the radiographic evaluation of bone quality is based on subjective assessment by the individual clinician. Therefore, the aim of this study was to examine classifications of bone tissue characteristics and methods for assessing them in dental implant planning and placement studies. Materials and Methods: Three databases (Pubmed, Scopus, Web of Science) were searched using specific index terms: "Bone quality, bone quantity, bone density, cone-beam CT and cone-beam computed tomography". Three reviewers selected titles and analyzed abstracts according to inclusion and exclusion criteria. Some descriptions of bone tissue characteristics (bone quality, density, and quantity) used before or during dental implant placement were selected and categorized. Results: The search yielded 442 titles. A total of 32 articles were selected and read in full text. Seventeen articles were considered relevant. Different classification systems were found to evaluate bone tissue characteristics as well as different examination protocols. Thirteen publications included in this review reported on bone quality and quantity using the Lekholm and Zarb classification. However, only four studies implemented and/or proposed modifications of the Lekholm and Zarb system. Four other publications described bone quality according to different classification systems such as Misch, University of California Los Angeles (UCLA), or Trisi and Rao. The assessment methods were often briefly described (or not described at all in one publication). Of the articles analyzed, five presented observer performance, whereas three presented diagnostic accuracy of the assessment method. Conclusion: Currently, there are different classification systems applied to dental implant planning and placement, particularly regarding whether bone quality or quantity affects treatment outcomes. However, most authors have not validated the diagnostic accuracy and reproducibility of the classification used. Therefore, it is necessary to develop a classification system consistent with characteristics of bone tissue, taking into consideration an adequate description of bone tissue assessment methods, their diagnostic accuracy, and observer performance.

Fear of COVID-19 associated with burnout syndrome in dentists of the Health Directorate of the National Police of Peru: a cross-sectional study at national level under multivariable regression model.

BACKGROUND: During the pandemic, many police dentists had the crucial responsibility of ensuring law and order while providing dental care by taking government-approved health measures to stop the spread of the coronavirus. The aim of this study was to assess the association between the fear of COVID-19 and Burnout syndrome in Peruvian dentists belonging to the Health Department of the National Police of Peru (PNP), taking into account possible confounding variables. METHODS: This cross-sectional and analytical study included 182 PNP dentists. The Fear COVID-19 Scale assessed fear of COVID-19 and the Maslach Burnout Inventory Test assessed burnout syndrome. The association between the fear of COVID-19 and Burnout syndrome (self-fulfilment) was analyzed using Spearman's Rho. A multivariable Poisson regression model with a robust variance estimation method was employed to evaluate the impact of fear of COVID-19 on the various dimensions of Burnout syndrome, considering possible confounding variables. The statistical significance level was set at p < 0.05. RESULTS: Under bivariate analysis, fear of COVID-19 was significantly linked with low direct intensity toward emotional exhaustion (Rho = 0.325, p < 0.001), very low direct intensity toward depersonalization (Rho = 0.180, p = 0.015), and very low inverse intensity toward self-fulfilment (Rho =-0.186, p = 0.012). Under multivariable analysis, it was observed that dentists who exhibited fear of COVID-19 were 3.4 and 3.7 times more likely to experience emotional exhaustion and depersonalization, respectively (APR = 3.40, 95% CI: 1.74-6.63 and APR = 3.68, 95% CI: 1.31-10.37), as compared to those who did not display fear of COVID-19. Moreover, none of the potential confounding factors were found to have a significant impact on emotional exhaustion (p > 0.05), depersonalization (p > 0.05), and self-fulfilment (p > 0.05). CONCLUSION: Fear of COVID-19 was significantly associated with emotional exhaustion and depersonalization, and inversely associated with self-fulfilment. PNP dentists who exhibited fear of COVID-19 were at greater risk for emotional exhaustion and depersonalization. In developing Burnout syndrome, no significant impact was observed from factors such as age, gender, marital status, children, hierarchy, years of service, work area, private practice, work over 40 h per week, type of service, work performed, sport practice and daily exercise time.

Factors associated with dental interns and professors perception of the management of disabled patients: A cross-sectional study under multivariable analysis.

Background: Patients with disabilities experience oral health inequalities, including increased disease prevalence and unmet healthcare needs. The aim of this study was to assess factors associated to the perceived management of patients with physical disabilities among dental interns and professors at a university located in the capital city and a branch in a province in Peru. Methods: This cross-sectional, observational, and analytical study included 100 dental interns and 75 Peruvian dental professors and was conducted from January to April 2022. A validated perception scale was used to evaluate the management of disabled patients. For the statistical analysis, the study employed Pearson's chi-square test and Fisher's exact test, along with a Poisson regression model that used robust variance. The adjusted prevalence ratio (APR) was utilized to evaluate perception while taking into account factors such as gender, age, marital status, origin, professional experience, previous treatment of a patient with physical disability, and previous cohabitation with a disabled patient. The significance level was set at p < 0.05. Results: The 86 % of dental interns and 88 % of dental professors had a poor perception of managing disabled patients, with no significant association between them (p = 0.698). Male and female dental interns displayed significant differences in perception (p = 0.004), while no other variables showed significant differences (p < 0.05). Conversely, dental professors displayed significant differences in all variables analyzed (p < 0.05). In dental interns, gender was found to be the only influential variable, with females having a 41 % higher likelihood of perceiving disabled patient management poorly compared to males (APR = 1.41; 95 % CI: 1.04-1.91) (p = 0.028). However, gender was not found to be a significant factor for dental professors (p = 0.449). Conclusion: The majority of dental interns and professors had a poor perception of managing disabled patients, with no significant differences observed between them. Moreover, gender significantly influenced the perception of managing patients with physical disabilities among dental interns specifically. On the other hand, neither age, marital status, origin, professional experience, previous treatment of a patient with physical disability, nor previous cohabitation with a disabled patient were found to be associated factors among dental interns and professors.

Effect of Polywave and Monowave Light Curing Units on the Microtensile Bond Strength and Failure Types of Different Bulk-Fill Resin Composites: An in vitro Study.

Aim: This study aimed to evaluate the effects of polywave and monowave light-emitting diode curing units on the microtensile bond strength and failure types of three bulk-fill resin composites. Materials and Methods: This in vitro experimental study was performed on 180 microbars obtained from human third molars and were distributed into 12 groups according to the type of bulk-fill resin composite and the light-curing unit. Third molars were restored using Filtek One Bulk Fill Restorative, Tetric® N-Ceram Bulk Fill, and Opus Bulk Fill resin composites was light-cured with Elipar Deep Cure L and Valo in three modes: standard, high power, and extra power. Subsequently, microtensile analysis was carried out with a universal testing machine and the type of failure with an optical stereomicroscope. For statistical analysis, the Kruskal-Wallis H-test was used, with the Bonferroni post hoc test and Fisher's exact test, considering a significance of p<0.05. Results: There were significant differences in the microtensile bond strength between the Filtek One Bulk Fill restorative and Opus Bulk-Fill (p = 0.042) when light was cured with the polywave unit at standard power. On the other hand, the Filtek One Bulk Fill Restorative and Opus Bulk Fill resins showed significant differences in microtensile bond strength when light was cured with the monowave unit compared with the polywave unit (p<0.05). Conclusion: The presence of alternative photoinitiator systems that are more reactive than camphorquinone produced higher microtensile bond strength in Tetric N-Ceram Bulk Fill and Opus Bulk Fill resins when light-cured with a high and standard polywave unit, respectively, compared to Filtek One Bulk Fill resins. Finally, Tetric N-Ceram Bulk Fill and Opus Bulk Fill resins had the highest percentage of mixed failures, while Filtek One Bulk Fill resin had adhesive failures, which was related to its lower microtensile bond strength.

Microtensile Bond Strength and Failure Mode of Different Universal Adhesives on Human Dentin.

AIM: The aim of this study was to compare the microtensile bond strength (µTBS) and failure mode of 4 different universal adhesive systems (UAs) on human dentin. MATERIALS AND METHODS: The study sectioned the occlusal thirds of 32 human third molars and divided them into 4 groups based on the adhesive system used. Group A: Palfique Universal Bond, Group B: Single Bond Universal, Group C: All-Bond Universal, and Group D: One Coat 7 Universal. The specimens underwent a 10,000-cycle thermocycling ageing process prior to testing (n = 32). Afterwards, 8 beams were obtained per group and subjected to µTBS testing using a digital universal testing machine at a speed of 1 mm/min. The microtensile bond strength values were analysed in Megapascals (MPa), and the failure mode was evaluated using a stereomicroscope. Welch's parametric ANOVA with robust variance and the Games-Howell post hoc test were used for µTBS comparisons, and Fisher's exact test was used to determine the association between adhesive type and failure mode. The significance level was set at P < .05. RESULTS: Group D showed a significantly higher µTBS than groups A (P < .001) and B (P < .001), but no significant difference was observed with group C (P= .075). Furthermore, groups B and C showed significantly higher µTBS than group A (P< .001 and P < .001, respectively), but there was no significant difference between groups B and C (P = .132). Additionally, group A exhibited a significant association with an adhesive failure mode (P < .05), whereas groups B, C, and D were significantly associated with a mixed failure mode (P < .05). CONCLUSION: The One Coat 7 Universal adhesive system showed higher microtensile bond strength values and higher chemical interaction with dentin compared to Palfique Universal Bond and Single Bond Universal. However, no significant differences were observed compared to All-Bond Universal.

Tensile Strength and Elastic Modulus of Gutta-percha Cones Disinfected with Sodium Hypochlorite at Different Immersion Times: An In Vitro Comparative Study.

Aim: The tensile strength and modulus of elasticity of gutta-percha cones can be chemically altered due to disinfectant solutions. Therefore, the aim of the present study was to compare tensile strength and elastic modulus of gutta-percha cones subjected to sodium hypochlorite (NaOCl) disinfection at different times. Materials and Methods: This in vitro and longitudinal experimental study consisted of 45 gutta-percha cones, divided equally into three groups: Group 1 (disinfection with 2.5% NaOCl), Group 2 (disinfection with 5.25% NaOCl), and control group. All groups were subdivided according to immersion times for 1, 5, and 10 minutes. Tensile strength and elastic modulus were measured with a universal testing machine. For comparing more than two independent groups, parametric analysis of variance test with Sheffe's post hoc was used and for multivariate analysis, and multivariate analysis of variance test based on Pillai's Trace was used. In all statistical analysis, a significance level P ≤ 0.05 was considered. Results: When comparing the tensile strength of gutta-percha cones, no significant differences were observed after being immersed at 1, 5, and 10 minutes in NaOCl 2.5% (P = 0.715) and 5.25% (P = 0.585). Regarding the elastic modulus, a significant decrease (P < 0.05) was observed in those that were immersed in NaOCl 2.5% and 5.25% for 1, 5, and 10 minutes. Furthermore, increased NaOCl concentration significantly reduced the elastic modulus (P < 0.001). However, there were no significant differences in tensile strength (P > 0.05) and elastic modulus (P > 0.05), when evaluating the interaction between NaOCl concentration and time. Conclusion: Increasing NaOCl concentration significantly reduced the modulus of elasticity without affecting the tensile strength of gutta-percha cones, regardless of immersion time. Furthermore, the interaction of time and NaOCl concentration did not significantly affect the tensile strength and elastic modulus.

Sociodemographic Factors Associated with the Satisfaction Level of Peruvian Dental Students with Virtual Classes During the Covid-19 Pandemic: A Prospective Bicentric Study.

Background: The pandemic caused by Covid-19 impacted all areas of social, economic and educational activity. When there is a high risk of spreading highly infectious diseases, education is usually the first service to be suspended. The objective was to evaluate the sociodemographic factors associated with the satisfaction level of Peruvian dental students with virtual classes during the Covid-19 pandemic. Methods: This observational, cross-sectional, analytical study evaluated 237 dental students from the capital city and one Peruvian province using a validated 13-item questionnaire to measure the level of satisfaction with virtual classes. Pearson's chi-square test and a logit model were used to evaluate the associated factors such as age group, sex, marital status, monthly family income, area of residence, place of origin, occupation and computer use, considering a significance level of p<0.05. Results: Of all students, 50.6%, 40.1% and 9.3% presented a good, average and poor level of satisfaction, respectively, with the virtual classes received. In addition, those with a monthly family income of less than 500 US dollars were 3.15 times more likely to have poor satisfaction compared to those with a monthly family income of more than 1000 US dollars (AOR = 3.15; 95% CI: 1.23-8.05). The rest of the variables evaluated were not considered influential factors in the levels of satisfaction with the virtual classes received. Conclusión: Of all students, 50.6% and 9.3% reported good and poor satisfaction with virtual classes during the COVID-19 pandemic, respectively. Monthly family income of less than 500 US dollars was an influential factor. In addition, the variables age group, sex, marital status, area of residence, place of origin, occupation and computer use were not found to be influential factors.

Shear bond strength of three different metal bracket base designs on human premolars: An in vitro comparative study.

Background: Adequate bracket-enamel bonding is critical to prevent detachment during orthodontic treatment and minimize any potential delay in results. The aim was to compare the shear bond strength of three metal bracket base designs: laser-structured base, mesh base, and retention grooves base. Material and Methods: In this experimental in vitro study, 54 human premolars were immersed for one week in 0.1% thymol solution, then placed in distilled water with weekly replacement until the start of the study. The premolars were cemented with brackets of varying base designs: A. Discovery® Smart (laser structured), B. Mini Master® Series (base with mesh), and C. Roth Max (base with retention grooves). All brackets were cemented using TransbondTM XT. A universal testing machine was used to evaluate the shear bond strength at a crosshead speed of 0.75 mm/min. Welch's one-factor ANOVA with robust variance and Tukey's post hoc test were used to compare means, with a significance level of p<0.05. Results: The average shear bond strength values were for the bracket with laser-structured base (14.78 ± 5.79 MPa), the bracket with mesh base (9.64 MPa ± 2.54 MPa) and the bracket with retention groove base (15.38 MPa ± 2.67 MPa). It was found that brackets with mesh bases had significantly lower shear bond strength than brackets with laser-structured bases (p=0.001) and brackets with retention grooves bases (p<0.001). No significant differences were observed between the latter two types of brackets (p = 0.893). Conclusions: The bracket base design influenced in vitro shear bond strength with significantly higher values observed for Roth Max and Discovery® Smart brackets compared to Mini Master® Series brackets. Key words:Shear strength, laser-structured bracket, bracket with mesh base, bracket with retention groove base.

Impact of an Educational Intervention on Oral Health Knowledge and Bacterial Plaque Control in Male Secondary School Students in a Peruvian Province: A Quasi-Experimental Study.

Background: The purpose of this study was to evaluate the effect of an educational intervention on oral health knowledge and bacterial plaque control in male secondary school students in a Peruvian province. Methods: This quasi-experimental study evaluated 294 male secondary school students in southern Peru. Oral health knowledge was measured with a validated 20-item questionnaire. Bacterial plaque was measured with the Simplified Oral Hygiene Index (OHI-S). This was rated as Excellent: 0, Good: 0.1-1.2, Fair: 1.3-3.0 and Poor: 3.1-6.0, before receiving the educational intervention and after four weeks of receiving it. Variables such as age, area of residence, having health professionals as family members, educational level of mother and father, and living with parents were considered. A significance level of p<0.05 was considered. Results: The comparison between the level of oral health knowledge and the OHI-S, before and after 4 weeks of receiving the educational intervention, showed a significant improvement (p<0.05) in all the categories of the variables studied. Likewise, before the educational intervention, there were significant differences in global knowledge about oral health among the categories of the following variables: age group (p=0.040), area of residence (p<0.001), educational level (father) (p=0.011) and living with parents (p<0.001). However, after four weeks of receiving the educational intervention, no significant differences were observed in all the variables studied (p>0.05). Regarding the OHI-S, no significant differences were observed in any of the variables studied, both before (p>0.05) and after four weeks (p>0.05) of receiving the educational intervention. Conclusion: After four weeks, the educational intervention significantly improved oral health knowledge and significantly reduced plaque bacterial plaque in male secondary school students in a Peruvian province, regardless of age, area of residence, having health professional family members, educational level of mother and father, and living with parents.

Sociodemographic factors associated with knowledge and attitudes of Peruvian dental interns about dental shade selection.

BACKGROUND: The dentist should have a thorough knowledge of the science, protocols and procedures for dental shade selection in order to mimic dental tissue with restorative materials, respecting the individual needs and attitudes of each patient and providing them with a pleasant and esthetically acceptable appearance. The present study evaluated the knowledge and attitudes of dental interns from two Peruvian universities about dental shade selection and its relationship with sociodemographic factors. METHODS: The present cross-sectional and analytical study was carried out on Peruvian dental interns from the Universidad Nacional Federico Villarreal and the Universidad Privada de San Juan Bautista during May to June 2022. Two validated questionnaires on knowledge and attitudes about dental shade selection were used. A Poisson regression model with robust variance using the adjusted prevalence ratio (APR) was used to assess the influence of the variables: age group, sex, place of origin and type of university, considering a significance level of p<0.05. RESULTS: The results showed that 40.8% (95% CI: 34.0% - 47.6%) of the interns presented unfavorable attitudes while 90.1% (95% CI: 86.0% - 94.2%) presented insufficient knowledge. It was also found that dental interns under 29 years of age were 32% less likely to have unfavorable attitudes (APR = 0.68, 95% CI 0.48 - 0.96) and 11% more likely to have insufficient knowledge (APR = 1.11, 95% CI 1.01 - 1.24) about tooth shade selection compared to dental interns aged 29 years and older. Finally, women were 55% more likely to have unfavorable attitudes about tooth shade selection compared to men (APR = 1.55; 95% CI: 1.08 - 2.22). CONCLUSION: The majority of dental interns presented insufficient knowledge and less than half had unfavorable attitudes about dental shade selection. In addition, being a student under 29 years of age was a risk factor for presenting insufficient knowledge and at the same time constituted a protective factor for presenting unfavorable attitudes. Likewise, being a female student was a risk factor for presenting unfavorable attitudes about dental shade selection.

Impact of a virtual educational intervention on knowledge and awareness of biomedical waste management among Peruvian dental professionals.

Waste from healthcare is a significant global issue, with around 85% of it being common waste and the remaining 15% being hazardous waste that is infectious and toxic. Dentistry uses various materials that create a substantial amount of biomedical waste capable of impacting the environment. Therefore, the purpose of this study was to assess the effects of a virtual educational program on the knowledge and awareness of dental material recycling and reuse, as well as biomedical waste management, among dental professionals in Peru. The current study was a longitudinal and quasi-experimental evaluation of 165 dentists from Peru. A validated questionnaire consisting of 30 items was administered at three different intervals (pre-test, immediate post-test, and 14-day post-test). Statistical analysis was conducted using the Mann Whitney U and Kruskal Wallis H tests to compare scores between categories of each sociodemographic variable, and the Cochrane's Q and Friedman test was used for related measures comparison. A significance level of p < 0.05 was considered. When comparing the percentage of correct responses regarding recycling and reuse of dental materials and biomedical waste management between the pre-test and the immediate post-test, a significant improvement in knowledge was observed for most of the questionnaire items (p < 0.05). At 14 days after the test, those who studied at a private university, unmarried, bachelors, non-specialists, non-teachers and have less than 10 years of professional experience did not did not retain knowledge on biomedical waste management (p < 0.05) or recycling and reusing dental materials (p < 0.05) to a significant extent. There was a significant enhancement in dentists' knowledge and awareness of managing biomedical waste, recycling, and reusing dental materials following the educational intervention. This improvement was observed across all sociodemographic variables considered in the study. However, this knowledge was not retained beyond two weeks for those who studied at a private university, unmarried, bachelor, with no specialty, non-teachers and with less than 10 years of professional experience. Government authorities should encourage oral health professionals to conduct research with educational interventions focused on improving and evaluating the sustainability and environmental impact of dental practices. This will enable professionals to better understand, control and evaluate the consequences of their practical work.

Resonance Frequency Analysis Mapping During Implant Healing Using a Nanostructured Hydroxyapatite Surface.

Aim: Stability measured by resonance frequency analysis (RFA) is an important factor to be considered in the success of dental implant treatments, which can be evaluated from the implant stability quotient (ISQ). The aim of the present case series was to map the RFA during healing of implants with nanostructured hydroxyapatite surface to describe the behavior of ISQ values related to individual factors. Materials and Methods: Twenty-three implants were placed in eight patients by conventional surgical protocol, and ISQ values were monitored from the day of implant placement until week 20. To obtain the ISQ values, an Osstell device was used and the placed implants were grouped in proportional amounts to describe the ISQ behavior considering the length (≤10 or >10 mm), the diameter (3.5 or 4.3 mm), the insertion torque (<40 N-cm or ≥40 N-cm), and the placement area (maxilla or mandible). Results: All the implants assessed decreased their values in the first 3 weeks after placement. Subsequently, the ISQ values increased by amounts similar to those obtained at the time of the placement and even more. Implants with length >10 mm, diameter 4.3 mm, and insertion torque ≥40 N-cm showed the highest ISQ values. Conclusions: A decrease in the ISQ values of dental implants with nanostructured hydroxyapatite surface was evidenced between weeks 2 and 3 considering length, diameter, insertion torque, and maxillary or mandibular placement site.

Sociodemographic Factors Associated with Knowledge About Management of Cleft Lip and Palate Patients in Peruvian Dental Students: A Logistic Regression Analysis.

Background: Cleft lip and palate are relatively frequent craniofacial alterations caused by the lack of union of the frontonasal processes with the maxillary processes during the first weeks of intrauterine life. This study evaluated the sociodemographic factors associated with the level of knowledge about management of cleft lip and palate (CLP) patients in Peruvian dental students. Methods: This analytical, observational, cross-sectional and prospective study evaluated 191 dental students belonging to two branches of a private Peruvian university (one branch in the capital city and the other in a province), from September to November 2022. A validated questionnaire of 14 closed multiple-choice questions was used. A logit model was used to evaluate the influence of the variables: sex, age, academic year of study, marital status, relationship with CLP persons, place of origin and area of residence, on the level of knowledge of the students considering a significance level of p<0.05. Results: Of the total, 77%, 22.5% and 0.5% presented a poor, fair and good level of knowledge, respectively, on the dental management of the patient with cleft lip and palate. In addition, those who lived in urban areas were 2.8 times more likely to have poor knowledge about the dental management of patients with CLP, compared to those who lived in non-urban areas (OR = 2.83; 95% CI: 1.26-6.33). Finally, sex, age, marital status, place of origin, academic year of studies and relationship with CLP persons were not considered influential factors (p>0.05). Conclusion: Most of the students showed a poor level of knowledge about the dental management of patients with cleft lip and palate, a risk factor being that the students live in an urban area. It is recommended that educational authorities include selected topics on CLP in subjects related to infant, child and adolescent care.

Microleakage in indirect onlay restorations cemented with three different types of adhesives: An in vitro study.

Background: To evaluate the in vitro degree of marginal microleakage in indirect Class II onlay restorations cemented with dual self-adhesive, universal adhesive and dual adhesive. Material and Methods: In the present in vitro experimental study, a total of 54 human premolar teeth were prepared and divided into three equal groups (n = 18) for placement of onlay-type restorations cemented with A: Allcem™ dual-cure adhesive cement), B: RelyX™U200 dual-cure self-adhesive cement and C: RelyX™ Ultimate universal adhesive cement. All restorations were subjected to 10,000 thermocycles between 5°C and 55°C and immersed in a 1M silver nitrate solution for 6 hours. The crowns were then sectioned mesiodistally and observed under a stereo microscope to determine the degree of marginal microleakage in the cervical area. Results: The onlay restorations cemented with RelyX Ultimate did not present microleakage in the majority of cases (77.8%). Restorations cemented with RelyX U200 showed predominantly microleakage up to the pulp floor in 83.3% of the total, being this significantly higher microleakage than in restorations cemented with RelyX Ultimate and Allcem Dual (p<0.001 and p<0.001 respectively). There was no significant difference in microleakage between the last two mentioned cements (p=0.255). Conclusions: Allcem dual adhesive cement and RelyX Ultimate universal adhesive showed significantly less microleakage than RelyX U200 dual-curing self-adhesive cement at the cervical level, with predominantly no microleakage and microleakage down to the enamel, respectively. The use of RelyX Ultimate cement in indirect restorations is recommended as it showed better marginal adaptation. Key words:Microleakage, human teeth, adhesion, adhesive cement, thermal cycling, onlay restoration.