Effectiveness of virtual simulation and jaw model for undergraduate periodontal teaching

Background The current study explored the effect of virtual simulation and jaw model on development of preclinical periodontal skills in undergraduate students. The study also sought to explore effectiveness of VR in periodontal preclinical training and determine adequate performance mode in basic periodontal education to improve future preclinical training strategies. Methods Sixty volunteer sophomores and juniors from the stomatology department in Lanzhou university were enrolled to the current study. Participants were randomly assigned into four groups (each group, n = 15) including the traditional jaw model group (Group J) which was the control group, virtual reality group (Group V), virtual-jaw group (Group V-J), and jaw-virtual group (Group J-V). Participants received training on uniform basic periodontal knowledge before completing the first theoretical assessment. Participants further underwent a total 8 h of operation training and completed a second theoretical assessment. Performance of participants was evaluated using the supragingival scaling processes, and clinical operation scores were graded by a blinded professional using an established standard scoring system. Results The findings showed no significant difference in the first theoretical outcomes between the four groups (P > 0.05). The scores of the second theoretical assessment were significantly improved for the V-J and J-V groups (60.00 ± 4.47, 58.33 ± 4.35) compared with the scores of the first theoretical exam (49.67 ± 4.81, 48.00 ± 4.93, P < 0.05). The operation process scores of students in Group V-J and J-V (72.00 ± 5.92; 70.00 ± 3.05) were significantly higher compared with the scores in the other two groups (V: 61.67 ± 7.85; J: 60.67 ± 2.58). The scaling process performance of students in Group V-J and J-V (53.00 ± 3.05; 63.40 ± 4.39) was improved compared with that of students in the other two groups (V: 41.90 ± 5.23; J: 47.40 ± 4.31). Conclusion The findings show that combination of virtual reality and jaw model during periodontal preclinical training increases students’ grades and improves acquiring of professional skills. Findings from the current study indicate that the jaw model should be applied prior to virtual reality to ensure high efficacy.

Decompression effects on bone healing in rat mandible osteomyelitis

Osteomyelitis (OM) of the jaw is usually caused by a chronic odontogenic infection. Decompression is the release the intraluminal pressure in the cystic cavity allowing gradual bone growth from the periphery. The aim of this study was to analyze the effectiveness of decompression in an OM jaw model. A 4-mm-diameter defect was made on mandibles of fourteen Sprague–Dawley rats and inoculated with S. aureus (20 μl of 1 × 107 CFU/ml) injection. Two weeks later, four groups were made as non-treatment (C1), only curettage (C2), curettage and decompression (E1), and curettage and decompression with normal saline irrigation (E2). After four weeks, each group was analyzed. Most micro-CT parameters, including bone mineral density [0.87 (± 0.08) g/cm3] with bone volume [0.73 (± 0.08) mm3] was higher in E2 group than that of C1 group (p = 0.04, p = 0.05, respectively). E2 group in histology showed the highest number of osteocytes than those of control groups, 91.00 (± 9.90) (p = 0.002). OPN were expressed strongly in the E1 (“5”: 76–100%) that those of other groups. Decompression drains induced advanced bone healing compared to that of curettage alone. Therefore, it could be recommended to use decompressive drain for enhancing the jaw OM management.

Comparative study on the effectiveness of virtual simulation and jaw model for undergraduate periodontal teaching

Background To compare the effect of virtual simulation and jaw model on the development of pre-clinical periodontal skills in undergraduate students and to improve future pre-clinical training strategies. Methods Sixty volunteer sophomores and juniors from the stomatology at Lanzhou University were enrolled in the current study and randomly divided into four groups: Jaw model (Group J, the control group), Virtual reality (Group V), Virtual-Jaw (Group V-J), and Jaw-Virtual (Group J-V). All of the participants received training on uniform basic periodontal knowledge before completing the first theoretical assessment. Then, they obtained total 8 hours of operation training and completed a second theoretical assessment. Their performance was evaluated using the supragingival scaling processes, and clinical operation scores were graded by a blinded professional using an established standard scoring system. Results There was no significant difference in the first theoretical outcomes between the four groups (P > 0.05). The second theoretical scores of the V-J and J-V group (60.00 ± 4.47, 58.33 ± 4.35) were significantly improved as compared with the first theoretical scores (49.67 ± 4.81, 48.00 ± 4.93, P < 0.05). The operation process scores of students in Group V-J and J-V (72.00 ± 5.92; 70.00 ± 3.05) were higher than those in the other two groups (V: 61.67 ± 7.85; J: 60.67 ± 2.58). Additionally, the scaling process performance of students in Group V-J and J-V (53.00 ± 3.05; 63.40 ± 4.39) was improved as compared with that of students in the other two groups (V: 41.90 ± 5.23; J: 47.40 ± 4.31). Conclusion The combination of virtual reality and jaw model during periodontal pre-clinical training may improve students’ grades and help them develop professional skill. More importantly, we suggest that the jaw model should be applied prior to virtual reality.

Determination of the Whitening Effect of Toothpastes on Human Teeth

Objective: The desire of individuals to have whiter teeth increases the interest in tooth whitening products. Our aim was to in vitro study the whitening effect of hydrogen peroxide, blue covarine and active charcoal containing whitening toothpastes on human teeth. Materials and Methods: A total of 40 extracted human incisor teeth were used in the study. To measure the whitening effect of toothpastes, the teeth were divided into four subgroups and placed in the phantom tooth jaw model. Then, daily brushing was done with an electric toothbrush. The colors of the teeth were measured initially using the spectrophotometer (single point and bleached shade mode) and at the end of 7th, 14th and 28th days. Whitening effectiveness of toothpastes were studied according to CIEDE2000 formula (∆E00) and shade guide units (SGU). One-way analysis of variance (ANOVA) and Tukey test were used in the statistical analysis of the data. (p<0.05). Results: Activated charcoal containing toothpaste showed the greatest whitening effect at the end of 7th, 14th and 28th days (p<0.05). There was no statistically significant difference between the whitening effects of hydrogen peroxide and conventional toothpaste (p>0.05). Blue covarine containing toothpaste had statistically the lowest whitening effect (p<0.05). Conclusions: All toothpastes showed a whitening effect on the teeth after 7 days of use. Activated charcoal containing toothpaste showed more whitening effect after 28 days of use than hydrogen peroxide, blue covarine and traditional toothpaste.

Dental Implant Site Drilling and Induced Morphological Changes Correlated with Temperature in Pig’s Rib Used as the Human Jaw Model

The bone tissue destruction during drilling is still one of the crucial problems in implantology. In this study, the influence of drilling speed, coolant presence, and its temperature on bone tissue was tested using swine rib as a biological model of human jaws. The same method of drilling (with or without coolant) was used in all tested samples. The microscopic investigation estimated the size of the destruction zone and morphology of bone tissue surrounding the drilling canal. The achieved results were statistically elaborated. The study proved that the optimal drilling speed was ca. 1200 rpm, but the temperature of the used coolant had no significant influence on provoked bone destruction. Simultaneously, the drilling system without coolant compared to this with coolant has statistical importance on drilling results. Further in vivo studies will verify the obtained results.

Decompression Effects on Suppurative and Sclerosing Osteomyelitis in the Jaw

Background: Osteomyelitis (OM) of the jaw is usually caused by a chronic odontogenic infection. Decompression is the release the intraluminal pressure in the cystic cavity allowing gradual bone growth from the periphery. The aim of this study was to analyze the effectiveness of decompression in an OM jaw model.Methods: A 4-mm-diameter defect was made on mandibles of fourteen Sprague-Dawley rats and inoculated with S. aureus (20 μl of 1x107 CFU/ml) injection. Two weeks later, four groups were made as non-treatment (C1), only curettage (C2), curettage and decompression (E1), and curettage and decompression with normal saline irrigation (E2). After four weeks, each group was analyzed.Results: Most micro-CT parameters of C1 and C2 were significantly lower, and bone mineral density with bone volume was enhanced in E2. E1 and E2 groups in histology showed prominent bone healing with a significantly high number of osteocytes, E2 had the weakest expression of IL-6 compared to that of C1. TNF-α and OPN were expressed strongly in the E1.Conclusion: Decompression drains induced advanced bone healing compared to that of curettage alone in an OM jaw model. Therefore, it could be recommended to use decompressive drain for the enhancement of jaw OM management.

Semi-Fixed Space Maintainer Treatment In Premature Loss Deciduous Tooth

Introduction: The period of deciduous teeth is an important period in child development. Damage to deciduous teeth that occur and cannot be treated conservatively will cause premature decay of teeth which is often called premature loss. A space maintainer is a passive tool used to maintain dental arches due to premature loss of deciduous teeth. Method: An 11-year-old girl accompanied by her mother came to RSGMP Unjani in 2018 with complaints of lower right back teeth missing because they have removed. The patient's mother is worried that her replacement teeth will not grow properly. Intraoral examination revealed tooth loss 85. The study model was analyzed using the Moyers method. Results: Analysis of the lower jaw model showed excess space. Patients were treated with a semi-fixed band and loop space maintainer on teeth 85. Conclusion: Premature loss results in excess space in the arch, so as to prevent further occlusion abnormalities in the child's growth and development process, we need a special tool used to maintain space due to premature loss of deciduous teeth.

Assessment and evaluation of errors in tooth preparation by undergraduate students: an institution based in-vitro study

Aim: To assess the errors made during preclinical tooth preparation by the undergraduate students of Meenakshi Ammal Dental College and Hospital, Chennai. Objectives: To understand the reason, nature and frequency of the errors occurring during tooth preparation done by undergraduate dental students during their preclinical practice. Materials and Methods: A total of hundred samples were collected from the undergraduate students. All the samples were upper right central incisors (11) typodont teeth, prepared to receive an All-ceramic crown. All the samples were prepared by mounting the typodont (NISSIN Typodont Jaw Model) on a phantom head simulator. All the preparations were made as freehand preparations. The following aspects of the preparation were evaluated: 1. Facial and palatal reduction 2. Occlusal clearance 3. Finish line width The evaluation of all the three aspects was done by studying a cross-section of an impression made on the prepared tooth. The impressions were made using a hard splint, which was fabricated on the typodont jaw model, prior to tooth preparation, as an impression tray. The impression material used was Light body(Zhermack Elite HD – Light normal set) impression material Results: The measurements and values obtained were subjected to statistical analysis to obtain the final result. Regarding the amount of prepared tooth surface, the frequency of errors encountered was more with regard to palatal reduction. Regarding the width of the finish line, Labial aspect of the finish line was most commonly under prepared. Conclusion: Within the limitations of the study, the main recommendation is to increase the pre-clinical practice time to emphasise more on the clinical expertise and the importance of proper operator positioning during tooth preparation. Key Words:Tooth preparation, All-ceramic restorations, Errors