Hands-on training based on quantifying radiant exposure improves how dental students cure composites: Skill retention at 2-year follow-up

Enhanced personal protective equipment and dental students' experience and quality of a restorative procedure in a simulated clinical setting

OBJECTIVES

To evaluate the effects of enhanced personal protective equipment (Enhanced_PPE) on student-operator's experience and restorative procedure.

METHODS

Student-operators (N = 29 Year 3 dental students) performed Class II composite restorations (SimpliShade, Kerr) in typodont upper molars (OneDental) equipped with N95 respirators, full-face shields, disposable headwear and gowns (Enhanced_PPE) or surgical masks, protective glasses/goggles and non-disposable gowns (Standard_PPE) 2 weeks later. Cavity dimensions were measured on cone beam computed tomography images. The quality of composite restorations was assessed using selected FDI criteria and Vickers hardness. A questionnaire assessed the operators' discomfort, anxiety, confidence, ability to perform, and procedure outcome. Data were analyzed using paired t-test and McNemar test (alpha = 0.05).

RESULTS

Student-operators experienced greater discomfort and anxiety, reduced confidence and ability to perform, and rated the procedure as less satisfactory with Enhanced_PPE (p < 0.05). Differences in proximal box width were marginally significant (Enhanced_PPE 1.8 ± 0.4 mm, Standard_PPE 1.6 ± 0.3 mm) (p = 0.047). Other cavity dimensions were similar between groups (p > 0.05) as were restorations regarding surface luster, anatomical form, marginal adaptation, proximal contour, and contact (p > 0.05). There were no differences in the hardness of composite restorations (top p = 0.349, bottom p = 0.334).

CONCLUSIONS

Enhanced_PPE led to student-operator discomfort, anxiety, and reduced confidence, but did not impact the quality of Class II preparation and composite restorations versus Standard_PPE.

Development of a three-dimensional printed model from a digital impression of a real patient for aesthetic dentistry undergraduate teaching

INTRODUCTION

The acquisition of skills and manual dexterity in aesthetic dentistry in undergraduate teaching requires preclinical practices with simulation that should approximate real clinical situations.

OBJECTIVE

We will present a digital procedure for the creation of three-dimensional (3D) resin models adapted to the practices of the Aesthetic Dentistry course.

MATERIAL AND METHOD

Stereolithography or Standard Tesellation Language (STL) files of a real patient were previously obtained with a 3-shape intraoral scanner. Using the Exocad computer programme for dental prosthesis design, various modifications were made, such as incisor rotation, surface alterations imitating dysplasias or erosions, the creation of diastemas, or even changes in tooth size. The virtual model was printed in resin for use by students. Once the practices were finished, the students and the teachers evaluated the use of the 3D printed models.

RESULTS

The result is the typodont model, in which seven laboratory sessions took place: 1-Restoration of conoid tooth morphology, 2-Cervical abrasion/ erosion restoration, 3-Direct Composite Veneer, 4-Aesthetic correction in a tooth with rotation, 5-Diastem closure, 6-Occlusal abrasions/ erosion, and 7-Maryland bridge. 90.48% of the students evaluated the designed 3D model as the best method for laboratory practice compared to other methods, obtaining a general assessment of 8.3 out of 10.

CONCLUSION

The method used has provided a reproducible standard analog model for direct aesthetic dental restoration practice, with a good assessment by students and teachers.

Skill Retention of Light-Curing Technique Using Only Verbal Instructions versus Using an Instructional Video: A 2-Year Follow-Up Study of Dental Students

PURPOSE

To evaluate the retention of light-curing skills among dental students after two years of clinical experience and determine if there are any differences in the skills retention between students who received verbal instructions or those who had received an instructional video. The students' satisfaction with past learning, self-confidence, and general knowledge about light-curing were also evaluated.

METHODS

This study is a 2-year evaluation of previous work. Students had previously been divided into two groups: those who received only verbal instructions, and those who received only an instructional video about the correct light curing technique to use clinically. Each student had light-cured simulated restorations (anterior and posterior) for 10 sec using the Managing Accurate Resin Curing-Patient Simulator (MARC-PS) (BlueLight Analytics, Halifax, Nova Scotia, Canada) and a multiple-emission peak light-emitting-diode (Bluephase N, Ivoclar Vivadent, Schaan, Liechtenstein) curing light. Students then received instructions according to their assigned group and light-cured the simulated cavities again. Two years later, students from both groups light-cured the same simulated cavities. Then, they completed a modified version of the National League of Nursing (NLN) satisfaction and self-confidence questionnaire and answered light-curing knowledge questions. Statistical analysis: The mean radiant exposure values delivered before receiving specific instructions on light curing, immediately after, and two years after instruction for both teaching methods (Friedman test followed by Wilcoxon signed-rank post hoc test), and the difference between both teaching methods was assessed (two-sample Wilcoxon rank-sum test). The satisfaction and self-confidence scores were compared between teaching method groups (Wilcoxon rank-sum test) (p<0.05).

RESULTS

The mean and median irradiance values ranged between 194-1777 and 1223-1302 mW/cm² before instructions, 320-1689 and 1254-1394 mW/cm² immediately after instructions, and 95-1945 and 1260-1331 mW/cm² two years later regardless of the simulated restoration or the teaching method. The mean and median radiant exposure values ranged between 2-23 and 12.5-13.6.4 J/cm² before instructions, 3-28 and 12.8-14.3 mW/cm² immediately after instructions, and 0.7-20 and 12.8-13.6 mW/cm² two years later regardless of the simulated tooth being light cured and the teaching method. Students retained their light-curing skills after two years of clinical experience, with no significant differences between both groups. The instructional video group delivered significantly higher radiant exposure values (p=0.021) when light-curing the anterior tooth than the posterior. Students were satisfied with their past learning and confident in their light-curing skills (p=0.020). There were statistical differences in how well the two groups remembered what they had been taught about light-curing. Only 5.7% of students answered all knowledge questions correctly.

CONCLUSION

Students retained their light-curing skills after two years of clinical experience, with no significant difference between verbal instructions or instructional video teaching methods. However, their knowledge about light curing remained very poor. Nevertheless, the students were satisfied with how they had been taught and had confidence in both teaching methods.

Depth of cure of 10 resin-based composites light-activated using a laser diode, multi-peak, and single-peak light-emitting diode curing lights

OBJECTIVES

To evaluate the depth of cure (DOC) of ten contemporary resin-based composites (RBCs), light-cured using different LCUs and exposure times.

METHODS

The power, radiant emittance, irradiance, radiant exposure (RE), and beam profiles from a laser (M, Monet), a multi-peak (V, Valo Grand), and single-peak (S, SmartLite Pro) LCU were measured. The DOC was measured using a 6-mm diameter metal mold and a solvent dissolution method to remove the uncured RBC. The length of the remaining RBC was divided by 2. The exposure times were: 1s and 3s for M, 10s and 20s for V, and 10s and 20s for S. Data were analyzed using: Bland-Altman distribution, Pearson's Correlation, and an artificial neural network (ANN) to establish the relative importance of the factors on the DOC (α=0.05; β=0.2).

RESULTS

Significant differences were found in the DOC of the different LCUs and composites. The laser LCU emitted the highest power, radiant emittance, and irradiance. However, this LCU used for 1 s delivered the lowest RE and produced the shortest DOC in all ten RBCs. The ANN demonstrated that the RE is the most critical factor for the DOC. Bland-Altman comparisons showed that the DOCs achieved with the laser LCU used for 1s were between 17 - 34 % shorter than the other conditions.

CONCLUSIONS

Although the laser LCU cured all 10 RBCs when used for 1s, it produced the shallowest DOC, and some RBCs did not achieve the minimum DOC threshold. The RE and not the irradiance was the most important factor in determining the DOC of RBCs.

CLINICAL SIGNIFICANCE

Despite delivering high power and irradiance, the laser used for l s delivered a lower radiant exposure than the conventional LCUs used for 10 s. This resulted in a shorter DOC.

Effectiveness of Using an Instructional Video in Teaching Light-Curing Technique

PURPOSE

To investigate dental students' ability to deliver satisfactory amounts of irradiance and radiant exposure to simulated cavities by teaching the light-curing technique using instructional video compared to verbal instructions.

METHODS

Students attended the didactic light-curing lecture explaining the light-curing technique. Participants were divided into two groups (n=60). Each participant light-cured a class III and a class I simulated cavities with sensors built-in a Managing Accurate Resin Curing-Patient Simulator (MARC-PS) system, using a multiple-emission-peak light-emitting-diode unit. Each student either 1) watched an instructional video (V) showing the light-curing technique, or 2) received individual verbal instruction (I). The light-curing performance, in terms of the mean irradiance and radiant exposure, was recorded. Each student performed light-curing again on the simulated cavities. Students' feedback for the corresponding teaching method was collected. Comparisons between before and after each instructional method were analyzed using the Wilcoxon signed-rank test. Comparisons between both instructional methods were analyzed using a Mann-Whitney U-test (α=0.05).

RESULTS

The students' light-curing performance improved after both methods, as observed on the MARC-PS laptop monitor. The mean irradiance values were anterior-V=1280.6 (183.2), anterior-I=1318.0 (143.5), posterior-V=1337.5 (181.1), posterior-I=1317.6 (248.2) mW/cm². The mean radiant exposure values were for anterior-V=13.5 (2.7), anterior-I=13.3 (1.6), posterior-V=13.7 (1.9), posterior-I=13.7 (2.5) J/cm². No significant difference was found between both instruction methods. Students reported that each method was effective.

CONCLUSION

Using V was comparable to I and an effective tool for teaching the light-curing technique per the students' ability to deliver sufficient amounts of irradiance and radiant exposure to simulated cavities.