Magnification in preclinical procedures: effect on muscle activity and angular deviations of the neck and trunk.

Objectives: This study aimed to assess the effects of different magnification systems on the angular deviations of the neck and trunk and the muscle activities of the upper back and neck during preclinical cavity preparation. Methods: This was an experimental laboratory study, with the angular deviations from the neutral positions of the neck and trunk and the activities of the bilateral upper back (the descending and ascending trapezius) and neck (sternocleidomastoid) muscles as the dependent variables. The independent variables were the different magnification systems used (Simple, Galilean, and Keplerian loupes, with direct vision as the control) and prepared teeth (teeth 16, 26, 36, and 46). A dental mannequin phantom head with artificial resin teeth was used, and Class I cavity preparations for composite resin were performed on teeth 16, 26, 36, and 46 using a 1012 round diamond bur at low speed. To analyze the angular deviations, the postures adopted during the procedure were recorded using a tripod-mounted camera positioned to provide a lateral view of the operator. A trained researcher measured the angular deviations using the software entitled "Software for Postural Assessment"-SAPO (version 0.69). Bilateral muscle activity was assessed using surface electromyography. Descriptive statistical analysis was performed, and after verifying the assumptions of normality and homoscedasticity, two-way analysis of variance and the Tukey and Games-Howell post-hoc tests were used to compare the data (α=0.05). Results: The angular deviation from the neutral position of the neck was found to be significantly higher during cavity preparations performed with the naked eye and the Simple loupe, irrespective of the prepared tooth. With regard to tooth location, the angular deviation of the neck was significantly greater during cavity preparation on teeth 16 and 26, and the angular deviation of the trunk was significantly greater during cavity preparation on tooth 26, regardless of the magnification system used. There were significant differences in right sternocleidomastoid muscle activity between the Simple, Galilean, and Keplerian loupes, with activity being the lowest for the Galilean loupe (p = 0.008). There were no significant differences in left sternocleidomastoid muscle activity between the loupes, regardless of the prepared tooth (p = 0.077). The activities of the bilateral descending trapezius and the right ascending trapezius muscles were significantly lower when the Galilean loupe was used (p < 0.010). Conclusion: These results suggest that the Galilean loupe resulted in lower muscle activity in the neck and back regions and that the Galilean and Keplerian loupes resulted in less angular deviations of the neck and trunk during cavity preparation.

Effect of finger rest positions on upper limb muscle activity during pre-clinical procedures.

Objectives: This study aimed to observe the effect of different finger rest positions on the muscular activity of the hand, forearm, arm, shoulder, thorax, and neck, as well as on the angular deviation from the neutral position of the neck, trunk, upper arm, and forearm on the working side during pre-clinical procedures. Methods: An experimental laboratory study was performed. Response variables were muscle activation of the abductor pollicis, brachioradialis, biceps brachii, deltoid, pectoralis major, and right sternocleidomastoid muscles and angular deviation from the neutral position of the neck, trunk, arm, and forearm during simulated clinical procedures. Independent variable was finger-rest position during cavity preparation (no finger rest, usual rest, and ergonomic rest). Class I cavity preparations (N = 120) were performed on artificial first molars (16, 26, 36, and 46) (N = 120). Muscular activation was assessed by surface electromyography and angular deviations using Software for Postural Assessment (SAPO) version 0.69. One-way analysis of variance and Tukey's or Games-Howell's post-hoc tests were performed (α = 0.05). Results: For the sternocleidomastoid muscle, there was no statistically significant difference between the different rest positions. For the deltoid muscle, work with no finger rest resulted in greater muscle activation (p < 0.001) during work on tooth 36. Regarding the pectoralis major and right brachioradialis muscles, we observed that for both teeth 16 and 26, working with ergonomic rest showed less muscle activation. Muscle activation of the right biceps brachii was higher for work with no rest in both the upper and lower arches, differing significantly only from the usual rest in tooth 16 (p < 0.001), usual rest and ergonomic rest in teeth 26 and 46 (p < 0.001), and only ergonomic rest in tooth 36 (p = 0.044). In the right abductor pollicis muscle, work with ergonomic rest resulted in less muscle activation for cavity preparation in teeth 16, 26, and 36, which was significantly different from work with no rest (p = 0.029, p < 0.001, and p = 0.013, respectively). Regarding angular deviation, it was observed that for tooth 16, there was a greater angular deviation of the arm when performing cavity preparations with no finger rest. For teeth 26 and 46, the ergonomic finger rest provided lower angular deviation from the neutral position of the right arm. For tooth 36, ergonomic rest provided less angular deviation from the neutral neck position. Conclusion: In general, the use of non-active finger rest during simulated cavity preparations, regardless of the type of rest, provided less muscle activation and angular deviation from the neutral position of the body's upper extremity when performing pre-clinical procedures.

Transition between preclinical and clinical training: Perception of dental students regarding the adoption of ergonomic principles.

OBJECTIVE: This study aimed to evaluate the perceptions of third-year dental students regarding the application of ergonomic principles in the transition between preclinical and clinical training in Restorative Dentistry. METHODS: We conducted a qualitative observational cross-sectional study. The sample consisted of forty-six third-year dental students at São Paulo State University (Unesp), School of Dentistry, Araraquara. Data was collected using an individual interview recorded on a digital voice recorder. A script containing questions related to the process of adaptation of students to clinical care with a view to ergonomic work posture was used. Data analysis was based on the quali-quantitative technique of Discourse of the Collective Subject (DCS), using Qualiquantisoft®. RESULTS: Most students (97.80%) perceived the need for an adaptation period in the transition from the preclinic to the clinic regarding ergonomic posture requirements; a part of them (45.65%) claimed that they still could not adapt, primarily due to the difference between the laboratory and clinic in the workstation (50.00%). Some students suggested longer preclinical training in a clinical environment to facilitate this transition (21.74%). The dental stool (32.60%) and the dental chair (21.74%) were the external factors that contributed most to making this transition difficult. The difficulty of the restorative dentistry procedure (10.87%) also interfered with posture. Additionally, the most challenging ergonomic posture requirements in the transition period were maintaining 30 to 40 cm between the patient's mouth and operator's eyes (45.65%), positioning the patient in the dental chair correctly (15.22%), and working with the elbows close to the body (15.22%). CONCLUSION: Most students perceived the need for an adaptation period in the preclinical transition to the clinic, attributing difficulties to adopt the ergonomic posture requirements, to use the workstation and to perform the procedures on real patients.

Preclinical dental training: Association between fine motor skills and compliance with ergonomic posture techniques.

OBJECTIVE: The aim of this study was to evaluate the dental students' fine motor skills and their compliance with ergonomic posture techniques over the course of a preclinical training year. The correlation between fine motor skills and compliance was also assessed. METHODS: The ergonomic posture of students enrolled in the second year of a five-year undergraduate dental degree programme (n = 62) was assessed using the Compliance Assessment of Dental Ergonomic Posture Requirements (CADEP). This assessment relied on photographs of the students performing preclinical laboratory procedures during the school year. The photographs of each procedure received a score, and the final score obtained (0 to 10) corresponded to the extent of the student's compliance with ergonomic posture techniques. Initial compliance was calculated during the first two months of the training programme, whilst final compliance was calculated during the last two months. Fine motor skills were evaluated using the modified Dental Manual Dexterity Assessment (DMDA), which was also applied at the beginning and the end of the school year. Data were assessed statistically by Student's paired t test, and the correlation between fine motor skills and compliance with ergonomic posture techniques was estimated by Pearson's correlation coefficient (r) and Student's t test (α = 0.05). RESULTS: The compliance scores were higher at the end of the academic year than at the beginning of year (p < 0.001; t = -5.300). Fine motor skills improved significantly with time (p < 0.001; t = -10.975). Non-significant correlations were found between students' fine motor skills and their economic posture compliance both at the beginning (r = -0.197; p = 0.126) and at the end of the training year (r = 0.226; p = 0.078). CONCLUSION: The students' manual dexterity and compliance with ergonomic posture techniques increased over the course of the preclinical training year, and the correlation between students' fine motor skills and their ergonomic posture compliance was not significant.

Stress amongst dental students in the transition from preclinical training to clinical training: A qualitative study.

OBJECTIVES: The present study sought to qualitatively evaluate third-year undergraduate dental students' perceptions of sources of stress during the transition from preclinical to clinical training. METHODS: This was an observational, cross-sectional, and qualitative study with a nonprobabilistic sampling design. The sample consisted of students in the third year of the five-year undergraduate degree program in dentistry offered by the São Paulo State University (UNESP), School of Dentistry, Araraquara, São Paulo State, Brazil (n = 37). Data were collected using open-ended, semistructured, and individual interviews that were recorded on a digital voice recorder. The students were interviewed on campus at a previously scheduled time. Efforts were made to provide a secure and welcoming environment for the interview. The interview questions addressed students' adaptation to clinical training and their perceptions of stress resulting from this transition. Data analysis was based on the qualitative and quantitative Discourse of the Collective Subject (DCS) technique performed with the aid of Qualiquantisoft®. RESULTS: Most of the students evaluated (75.7%) reported difficulty in the transition from the preclinical to the clinical phase of their program and that this difficulty increased their stress levels during this transition (81.1%). The most frequently cited reason for the increase in stress was the responsibility and demands associated with caring for real patients (54.1%). Almost half of the students (48.6%) reported feeling physical symptoms of stress such as tachycardia, dizziness, headache, and muscle tension during this period. Most of the students (81.1%) required up to one semester to feel that they had adapted to the clinic. Many students used stress reduction strategies such as simply trying to calm down, studying before their clinical work, improving organisation, and asking professors for help. Adaptation to ergonomics and biosafety in the clinic was the most frequently cited impediment (45.9%) to the adaptation process. The students' main suggestions for reducing stress in this transition phase were additional preclinical training in a clinical setting, a more gradual transition, and greater professor receptiveness. CONCLUSION: The dental students interviewed herein perceived high levels of stress during the transition from preclinical to clinical training.

Stress among dental students transitioning from remote learning to clinical training during coronavirus disease 2019 pandemic: A qualitative study.

OBJECTIVES: To identify dental students' perceptions of stress over returning to in-person clinical training after remote learning required from the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This was a qualitative observational study. The sample was composed of undergraduate students (n = 47) in the final year of São Paulo State University, School of Dentistry, Araraquara program. The data were collected using a questionnaire created in Google Forms. The data was analyzed using the discourse of the collective subject technique. RESULTS: More than half of the students (63.8%) reported experiencing stress in the transition from remote learning to clinical training. According to the students, the main causes of this stress were fear of COVID-19 infection or contamination (31.5%) and insecurity in their clinical treatment skills after having gone so long without training (25.5%). Half of the students surveyed (51.1%) exhibited at least one stress-related symptom. For most of the students (70.2%), remote learning was insufficient to prepare them for returning to in-person clinical activities. Performing laboratory pre-clinical activities prior to clinical training was the suggestion most frequently cited by the students (25.5%), as a way to avoid some of the stress associated with their return to in-person learning. The main coping strategies adopted by the students upon their return to in-person learning were making the most of their clinical training, planning cases, and studying relevant topics before treating patients (48.9%). CONCLUSION: The dental students perceived high levels of stress during the transition from remote learning to clinical training.

Effect of magnification factor by Galilean loupes on working posture of dental students in simulated clinical procedures: associations between direct and observational measurements.

Objectives: To determine the effect of different levels of Galilean loupe magnification on working posture as measured by compliance with ergonomic posture positions, angular deviation from the neutral position of the neck, and muscle activation in the neck and upper back region during simulated clinical conditions. Methods: An experimental laboratory study was performed in which the dependent variables were compliance with ergonomic posture requirements while performing simulated restorative procedures in Restorative Dentistry, angular deviation from the neutral position of the neck, and muscle activation in the neck and upper back. The independent variable was the level of Galilean loupe magnification, which was tested at four levels (naked eye, 2.5× magnification, 3.0× magnification, and 3.5× magnification). The cavity preparations and Class I composite resin restorations were performed on artificial first molars on a mannequin in a dental chair. The Compliance Assessment of Dental Ergonomic Posture Requirements (CADEP) was used for the postural analysis; as was an analysis of the angular deviation from the neutral position of the neck and surface electromyography. Working posture was recorded on video over the course of the procedure. Participants were filmed from three different angles. The Compliance Assessment of Dental Ergonomic Posture Requirements (CADEP) assessed compliance with ergonomic posture requirements. A locally produced posture assessment software analyzed angular deviation. Surface electromyography bilaterally assessed activation of the sternocleidomastoid, descending trapezius and ascending trapezius muscles. Two-factor analysis of variance (ANOVA) and either Tukey's post-hoc test or the Games-Howell post-hoc test were performed (α = 0.05). Results: During the cavity preparations and restorations, the use of Galilean loupes at all magnifications positively influenced working posture as measured by participants' compliance with ergonomic posture positions (p < 0.01) and neck angulation (p < 0.01); the use of these loupes did not affect muscle activation in the regions evaluated (p > 0.05). Conclusion: The use of Galilean loupes had a positive effect on dental students' working posture during the restoration procedures performed.

Development and assessment of an indirect vision training programme for operatory dentistry: Effects on working posture.

OBJECTIVES: Students experience difficulty working with indirect vision and often adopt inadequate working postures because of it. This study created and then assessed the effects of an indirect vision preclinical training programme on dental students' working posture. METHODS: The study enrolled students in the third year of the 5-year undergraduate programme in dentistry in the School of Dentistry of São Paulo State University (UNESP), Araraquara (N = 54). The programme consisted of four training sessions in which students performed different types of activities in which only a mirror was used to see the procedure they were performing. To evaluate posture, students were asked to perform class III cavity preparations (distal-palatal and mesial-palatal preparations) on upper central and lateral incisors in a dental mannequin (tooth numbers 11, 12, 21 and 22) both before and after the indirect vision training programme. Photographs were taken of the students' working postures. The photographs were assessed by a duly trained researcher using the Compliance Assessment of Dental Ergonomic Posture Requirements. A descriptive statistical analysis was performed, and the assumptions of normality were verified. Student's paired t test was also performed. The significance level adopted was 5%. RESULTS: A significant difference was found between the percentages of correct ergonomic postures adopted before and after the training programme (p = 0.039). CONCLUSIONS: The preclinical training programme for indirect vision was found to have a positive effect on the working postures of the students evaluated herein.

University engagement of dental students related to educational environment: A transnational study.

OBJECTIVES: To investigate the validity and reliability of the University Student Engagement Inventory (USEI) in its complete and reduced versions with Brazilian and USA students, and to evaluate the influence of gender and academic level on students' university engagement in both countries. METHODS: A cross-sectional observational study with a non-probability sample was conducted. The sample comprised dental students of both genders, 154 from a university in New York, USA (response rate 91.1%) and 459 from two universities in Brazil (response rate 79.1%). University engagement was measured using the USEI. The samples were characterized by gender and academic level. RESULTS: The refined reduced version of the USEI presented adequate fit to the samples from both countries. Gender was associated with the behavioral engagement factor of the USEI in Brazilian students. In the USA sample, gender was associated with the behavioral and cognitive engagement factors. There was a significant effect of academic level on behavioral and emotional engagement for the Brazilian and USA samples, respectively. CONCLUSION: The refined reduced USEI presented adequate psychometric qualities for the study samples.

Magnification effect on fine motor skills of dental students.

OBJECTIVES: This study observed the effect of different magnification systems on dental students' real and perceived fine motor skills. METHODS: This was a laboratory-based experimental study. Students in the fifth year of an undergraduate dentistry program (N = 92) participated in this study. The dependent variables were real motor skills, perceived motor skills and time required to complete the fine motor skills test. The independent variable was the use of a magnification system under four conditions. For each condition, the Dental Manual Dexterity Assessment was performed, which consisted of inserting the #3195FF bur into targets positioned on a Styrofoam plate. The accuracy of each penetration of the targets was scored, using a point system with a maximum possible score of 246 points. Students' perceived fine motor skills were assessed using a visual analog scale (VAS) that ranged from zero for no skills to ten for maximum skills. A descriptive statistical analysis and the repeated measures ANOVA were performed (α = 0.05). RESULTS: The Galilean and Keplerian loupes were found to positively affect students' real fine motor skills (p<0.01); however, perceived fine motor skills and time were significantly better (p<0.01) under the naked eye. CONCLUSIONS: Dental students' real fine motor skills were better when Galilean and Keplerian loupes were used, but the perceived fine motor skills were not.

Bioadhesive Curcumin-Mediated Photodynamic Inactivation and Its Potential to Cause Undesirable Effects on Dental and Restorative Surfaces.

Curcumin-mediated Photodynamic Inactivation (PDI) has shown great potential to disinfect specific sites on tooth enamel but may involve contact with restorative materials. Thus, before use in dentistry, it is necessary to investigate whether the PDI protocol causes undesirable changes in the surfaces of aesthetic restorative materials and dental enamel. This study investigated the effect of PDI mediated by curcumin (CUR) in a liquid crystal precursor system on color stability (ΔE), surface roughness (Ra), and microhardness (kgf) of three different composite resins and bovine dental enamel specimens. The microhardness and roughness readings were performed 60 days after the treatments while the color readings were performed immediately, 24, 48, and 72 h, 7, 14, 21, 30, and 60 days after the treatments. Results showed that CUR mediated-PDI does not seem to have the potential to promote any esthetic or mechanical changes to the surface of tooth enamel and can be applied safely in clinical practice. However, the results on color, roughness, and hardness obtained for composite resins show that some negative effects can be produced, depending on the type of restorative material; more experiments must be performed with different formulations and, perhaps, with lower concentrations of CUR.

Ergonomic working posture in simulated dental clinical conditions: effect of magnification on the operator's experience.

OBJECTIVES: This study observed the effect of different magnification systems on working posture and neck angulation during cavity preparation procedures according to operator's experience. METHODS: This was a laboratory study. The response variables were the neck angulation and the working posture adopted during Class I cavity preparations (N = 640) that were performed under four conditions (unaided visualization, simple loupe, Galilean loupe and Keplerian loupe). Working postures were recorded and evaluated by the Compliance Assessment of Dental Ergonomic Posture Requirements (CADEP). The two-factor ANOVA and Games-Howell post-hoc test were performed (α = 0.05). RESULTS: For all treated teeth it was observed higher posture scores and lowest neck angulations while using the Galilean and Keplerian loupes (p < 0.01). No correlations were found between operator's experience and working posture (p = 0.71-0.88). CONCLUSION: It can be concluded that Galilean and Keplerian loupes helped operators to maintain an ergonomic posture and lower neck angulations for all teeth and the operator's experience provided better ergonomic posture for the mandibular teeth.

Magnification loupes in dentistry: A qualitative study of dental students' perspectives.

INTRODUCTION: The nature of the oral operating field makes it a challenge for dentists to work while maintaining musculoskeletal health. Strategies have been studied in recent years to improve visualisation of the operating field, and the use of magnification systems has been recommended for providing additional benefits. Despite the growing body of evidence suggesting that the use of magnification improves visual acuity, the dentist's posture and the quality of dental procedures, few studies have analysed users' perspectives on these devices in terms of their adaptation process. These types of studies are important because they provide insight into the reality of the adaptation process required by magnification systems so that adjustments and improvements can be made to adapt these systems to the users' reality. Thus, we sought to explore the perspectives held by second-year students in an undergraduate dental program on the use of dental loupes during pre-clinical laboratory activities. MATERIALS AND METHODS: A total of 24 second-year dental students participated in semi-structured interviews exploring their perspectives of wearing dental loupes during their pre-clinical activities. Data collection and analysis were consistent with the qualitative content analysis methodology. All interview data were analysed using version 10 of the NVivo® analytical software. RESULTS: Participants described that magnification can lead to the improvement of their work postures, hand skills and quality of dental procedures. Nevertheless, they reported a need for an adaptation period and for adjustments to the technical features of the magnification system. CONCLUSION: The students had positive perspectives on the use of magnification in their dentistry training program, including improvements in posture, hand skills and procedure quality.

Implementing magnification during pre-clinical training: Effects on procedure quality and working posture.

OBJECTIVE: The objective of this study was to evaluate the effects of magnification on the quality of two pre-clinical procedures, class I cavity preparations and composite resin restorations, and to evaluate the working posture. METHODS: This was an experimental laboratory study. The response variables were the quality of cavity preparations and Class I restorations as well as the working posture adopted during the execution of these procedures. The independent variables were the magnification system under four levels (unaided visualisation, the use of a simple loupe, the use of a Galilean loupe and the use of a Keplerian loupe) and the artificial teeth treated. Class I cavity preparations and restorations (N = 320) were performed using standardised procedures, and the quality achieved was evaluated using pre-established criteria. Working posture was recorded using digital video cameras and was evaluated using the Compliance Assessment of Dental Ergonomic Posture Requirements (CADEP). A two-factor analysis of variance (ANOVA) and multiple comparison test were performed (α = 0.05). RESULTS: The quality of cavity preparation did not differ significantly amongst the different magnification systems (P = 0.082). Galilean and Keplerian systems had a positive impact on restoration quality only for the left mandibular first molar (P = 0.04). Higher posture scores were observed when Galilean and Keplerian loupes (P = 0.01) were used, regardless of the tooth being treated. CONCLUSION: The use of Galilean and Keplerian magnification lenses did not affect the quality of the pre-clinical procedures performed whilst improved the scores of ergonomic posture.

Preclinical dental training: Association between difficulty in performing restorative procedures and the adoption of ergonomic posture.

OBJECTIVE: The aim of this study was to determine any correlations between difficulty in performing restorative procedures and the adoption of ergonomic posture by dental students in a preclinical course. METHODS: The sample was composed of second-year undergraduate students enrolled in the School of Dentistry of São Paulo State University (UNESP), Araraquara (n = 56). The data were collected from weekly records in which students who had participated in training in a preclinical restorative dentistry laboratory registered the difficulty they experienced performing given proposed preclinical procedures and adopting ergonomic posture (positioning of students' legs, thighs, spine, arms, and forearms, as well as the positioning of both the dental light and the dental mannequin's head, the distance between the operating field and the operator's eyes, and the location of the instruments used in the procedures). Answers were provided on a scale of zero to ten points (zero = no difficulty; 10 = maximum difficulty). A descriptive statistical analysis was performed. The correlation between the level of difficulty in performing the restorative procedures and in the adoption of ergonomic posture was estimated using the Pearson correlation coefficient (r), and its significance was tested using Student's t test. To evaluate the effect of time on students' perceived difficulties in implementing ergonomic posture, the first 2 weeks of training was defined as the initial time, whilst the last 2 weeks was defined as final time (scores from these periods were averaged). After the normality assumptions were verified, Student's t test for paired samples was performed. The significance level adopted was <5%. RESULTS: A correlation was found between the difficulty students experienced performing the preclinical procedures and their difficulties implementing ergonomic posture; the correlation was significant, though the correlation ranged from slight to moderate (P < 0.001; r = 0.38-0.63). In addition, the data also showed that the students' perceptions of how difficult it was to implement these posture items decreased significantly over time (P < 0.001). CONCLUSION: The correlation between perceived difficulty in performing the preclinical restorative dentistry procedures and the application of ergonomic posture was slight to moderate, and the students' perceived difficulties in maintaining ergonomic posture decreased over the course of the school year.

Effect of magnification devices on dental students' visual acuity.

This study aimed to determine dental students' visual acuity and neck angulation when using magnification devices and distances from the operating field. Forty students from each of the second through fifth years of the five-year program at the School of Dentistry of Araraquara were selected (N = 160). Visual acuity was tested using a miniature Snellen eye chart under five different settings (naked eye; simple loupe; Galilean loupe; Keplerian loupe and an operating microscope). Photographs were taken during the visual acuity exam in order to evaluate the angulation of the subjects' necks in a neutral posture. The two-factor analysis of variance and the Games-Howell post-hoc test were performed (α = 0.05). A significant difference in visual acuity and neck angulation was found between the "magnification device" and "distance" factors in each of the graduating classes analyzed (p<0.05). At a standardized distance, the Keplerian loupe (535.93±133.69), the Galilean loupe (514.06±171.56), and the operating microscope (517.71±161.61) all provided greater visual acuity. At a subjectively comfortable distance, the Keplerian (521.35±157.99) and Galilean (515.00±156.32) loupes produced the best visual acuity. The angulation of the neck was greater when the simple loupes (56,59±10,88) and naked eye (56.51±13.55) were used at a subjectively comfortable distance. At both a standardized distance and a comfortable distance, the Galilean and Keplerian magnification systems provided the best visual acuity and the lowest angulation of the operator's neck. At a standardized distance of 30 cm to 40 cm, the operating microscopes produced similar results.

Cross-infection control in clinical training: Development of a device for storing a composite resin in restorative dentistry.

This study presented a biosafety device for the hygienic storage of composite resin during restorative procedures in teaching clinics, RESTAURASAFE, and to compare the color stability, surface hardness, and degree of conversion of the composite resin made with the proposed device to those of conventionally made resins. Esthet-X HD composite was manipulated directly from the syringe, fractionated doses, dappen dish or RESTAURASAFE. Disc-shaped specimens were immersed in artificial saliva and coffee for 60 days and the color stability and the Vickers surface hardness were evaluated during 60 days. Degree of conversion was assessed after immersing specimens in saliva (baseline). The surface morphology analysis of composite resin has taken by scanning electron microscopy (SEM). The data were evaluated statistically by repeated measures ANOVA (α=.05). No difference of color stability was observed for saliva and coffee regardless of storing devices. The resin manipulated directly from the syringe presented lower hardness, and fractionated doses presented lower degree of conversion than the RESTAURASAFE. SEM analysis showed that after artificial aging in coffee for 60 days, the specimens prepared with fractionated doses of resin displayed the fewest changes in surface morphology, followed by those prepared with the RESTAURASAFE. We conclude that RESTAURASAFE allows to obtain similar color stability, higher hardness, and degree of conversion of the composite in comparison to the other storing devices.

Development of a method to assess compliance with ergonomic posture in dental students.

CONTEXT: The ergonomic posture protocol is extremely important for the maintenance of occupational health in dentistry. The lack of compliance with this protocol results in a high risk of developing musculoskeletal disorders. AIMS: This study developed a direct observation method for the evaluation of dental student compliance with ergonomic posture protocol. SUBJECTS AND METHODS: The method is named compliance assessment of dental ergonomic posture requirements (CADEP). During the development of the method, 14 items were elaborated considering the theory of dental ergonomics. Each item should be classified as appropriate, partially appropriate, or inappropriate. After evaluation, all item values should be added, and the final score expressed as the percent of compliance with correct postures, with a score range of 0%-100%. STATISTICAL ANALYSIS USED: The reliability of CADEP was assessed through intra- and interobserver reproducibility. For the CADEP application, 73 senior year students from the undergraduate course in dentistry were evaluated. The intra- and interexaminer concordance was estimated using the intraclass correlation coefficient (ρ). A descriptive statistical analysis was performed. RESULTS: The reproducibility of evaluator 1 (ρ =0.90; confidence interval [CI] 95%: 0.83-0.94), evaluator 2 (ρ = 0.83; CI 95%: 0.70-0.90), the interexaminer in the first evaluation (ρ = 0.81; CI 95%:0.67-0.89), and in the second one (ρ = 0.76; CI 95%: 0.59-0.87) was classified as good. In the analysis of the compliance, it was verified that moderate compliance was the most prevalent among the evaluated students (65.6%, CI 95%: 60.3%-70.7%). CONCLUSIONS: CADEP was valid and reliable for the assessment of dentistry students' compliance regarding ergonomic posture requirements.

The Disabilities of the Arm, Shoulder and Hand scale in the evaluation of disability - A literature review.

Work-related musculoskeletal disorders (WRMDs) interfere with workers' productivity and quality of life. Thus, early detection of disabilities caused by WRMDs is vital for preventing the aggravation of symptoms. Early detection aids and is aided by educational and preventive programs. WRMDs can be detected using the Disabilities of the Arm, Shoulder and Hand (DASH) Scale. OBJECTIVES: The present study aimed to review the literature on the application of the DASH Scale through a consideration of the cultural adaptation process and an evaluation of the scale's psychometric properties. METHODS: The literature review was conducted using the terms "disabilities", "musculoskeletal disorders", "DASH" "questionnaire" and "upper limbs". RESULTS: Forty-eight articles were collected, and these included only articles available in English which contained the full version of the DASH Scale and which focused on the evaluation of its psychometric properties (n=25). CONCLUSION: Most of the studies partially evaluated the psychometric properties of the DASH instrument; however, these properties were typically evaluated using only a correlation analysis involving other instruments.

Antibacterial activity of glass ionomer cement modified by zinc oxide nanoparticles.

This study evaluated the antibacterial activity of zinc oxide nanoparticles incorporated into self-cured glass ionomer cement (GIC) and light-cured resin-reinforced GIC on Streptococcus mutans biofilm. The GICs, Fuji II (GC America) and Fuji II LC (GC America), were incorporated with nanoparticles at concentrations of 0%, 1%, and 2% by weight, and the biofilm maturation time was one and seven days. Circular specimens of each GIC type were prepared. The antibacterial activity was evaluated by determining the number of colony forming units of S. mutans strain per milliliter. Morphology of the biofilm was analyzed by scanning electron microscopy (SEM). The data obtained for each GIC were analyzed by two-way ANOVA (α = 5%). For chemically activated GIC, no significant difference was observed in relation to the time of biofilm maturation (p = 0.744), concentration of nanoparticles (p = 0.966), and their interaction (p = 0.800). The results from analysis of GIC modified by light-polymerized resin showed that only of the maturing time significantly affected the number of adhered cells on the biofilm (p = 0.034, F = 4.778). The more mature the biofilm, higher the number of cells. SEM analysis showed no change in cell morphology in relation to the type of GIC, maturation time, and nanoparticles concentration. We conclude that the inclusion of zinc oxide nanoparticles at concentrations of 1% and 2% by weight into the GICs evaluated here, did not promote their antimicrobial activity against S. mutans.