Assessment of a virtual prosthetic case planning environment for dental education - A multicentric analysis.

OBJECTIVES: The aim of the present study was the multicentric assessment of the virtual prosthetic case planning environment (VCPE), which relocates patient planning into the virtual space in dental education. MATERIALS AND METHODS: The VCPE is separated into two rooms: a virtual entry area where the user can choose between 10 different prosthetic case plans of ascending complexity, and a virtual patient case planning room. In spring term 2022, the use of virtual case planning was voluntarily assessed in four different German dental schools (DSs) from the perspective of both lecturers and students. The assessment was performed afterwards using a questionnaire. Data were analysed using Kolmogorov-Smirnov test, exploratory data analysis, Fisher-Freeman-Halton test, and exact Fisher test. Reliability was assessed with Cronbach Alpha test (α < 0.05). RESULTS: A total of 59 lecturers and 63 students were included. There were 38.5% male, 60.7% female, and 0.8% diverse participants. The mean age of the lecturers was 36.2 ± 9.0 years and of the students 24.3 ± 3.0 years. The VCPE was assessed as good, yet the evaluations between either the DSs or between the lecturers and students were significantly different. CONCLUSIONS: Even though for some assessment criteria significantly different results between the four DS were observed, the majority of participants evaluated the VCPE positively and recommended them for teaching. The virtual reality as a teaching method for teaching prosthetic case planning for the further preparation of the students for the later professional life can be considered as helpful.

Impact of different types of dental prostheses on oral-health-related quality of life: a prospective bicenter study of definitive and interim restorations.

PURPOSE: To assess the impact of different types of dental prostheses, including definitive and interim restorations, on oral health-related quality of life (OHRQoL) before and after prosthetic treatment. MATERIALS AND METHODS: A total of 151 patients received prosthetic treatment at one of two German departments of prosthetic dentistry. The patients' OHRQoL was assessed using the German version of the Oral Health Impact Profile (OHIP-G53) at baseline (T0) and at 1 week (T1) and 3 months (T2) after treatment. Patients were divided into 10 subgroups according to their pre- and posttreatment status. The effect of the type (no prosthesis; fixed prosthesis; removable prosthesis) and duration of wear (definitive; interim) of the restorations was evaluated. Results were analyzed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests with a significance level of P = .05. RESULTS: The highest OHRQoL was recorded for patients with fixed restorations, as indicated by the fact that their OHIP scores were lowest. A significant improvement in OHRQoL (P ≤ .034) was observed for patients who needed prostheses and were then treated with removable or fixed restorations. The OHIP score was affected by a change in restoration type. Rehabilitation with definitive prostheses had a significant effect on posttreatment OHRQoL (P ≤ .006). CONCLUSION: In general, prosthetic rehabilitation by use of fixed or removable prostheses resulted in an improvement in OHRQoL. The use of the same type of restoration before and after treatment had a positive effect on OHRQoL. If possible, a change of restoration type should be avoided. For patients who require permanent prostheses, the use of fixed and removable restorations is recommended. For oral rehabilitation, fixed restorations should be preferred in order to achieve best possible improvement of OHIP score.

Oral health-related impact profile of patients treated with fixed, removable, and telescopic dental prostheses in student courses-a prospective bicenter clinical trial.

OBJECTIVES: To analyze the oral health-related impact profile in patients treated with three different types of dental prosthesis in student courses. MATERIALS AND METHODS: This prospective bicenter clinical trial was conducted with 151 patients being treated with fixed (n = 70), removable (n = 61), or telescopic dental prostheses (n = 20) in clinical student courses of two German universities from October 2018 to October 2019. All patients completed three standardized German versions of the Oral Health Impact Profile (OHIP-G49/53) before prosthetic treatment (T0), at control after 1 week (T1), and after 3 months (T2), divided into five dimensions: (a) appearance, (b) oral function, (c) psychosocial impact, (d) linguistic limitations, and (e) orofacial pain. Data were analyzed with Kolmogorov-Smirnov, Wilcoxon signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests. RESULTS: Within T0-T1 and T0-T2, greater improvements were determined for removable compared with fixed dental prostheses for the dimensions' oral function (p ≤ 0.014), linguistic limitations (p ≤ 0.016), and appearance (p ≤ 0.003). No significant differences were found between fixed and telescopic dental prostheses (p ≥ 0.104) or between removable (partial dental prosthesis with clasps and complete dental prosthesis) and telescopic dental prostheses (p ≥ 0.100). Within T1-T2, a significant improvement in orofacial pain could be determined (p = 0.007). CONCLUSIONS: Restorations presented an improvement in oral health-related quality of life. Removable dental prostheses showed better improvement than fixed ones in various dimensions. CLINICAL RELEVANCE: Knowledge about the influence of oral health-related quality of life on the three different types of prosthesis used in student courses can be of decisive help in dental consultations.

Clinical performance of occlusal onlays made of lithium disilicate ceramic in patients with severe tooth wear up to 11 years.

OBJECTIVES: Evaluation of survival and complication rate of monolithic occlusal onlays made of lithium disilicate ceramic used in patients with severe tooth wear up to 11years of clinical service. METHODS: In a prospective non-randomized clinical study 7 patients (4 male, 3 female; median age: 44.3±6.56years old) were restored full mouth with a total of 103 adhesively bonded occlusal onlays made of lithium disilicate ceramic (IPS e.max Press, Ivoclar Vivadent, Schaan, Liechtenstein). All restorations were examined during annual recall visits using periodontal parameters according to the modified United States Public Health Service (USPHS) criteria: (a) marginal discoloration, (b) secondary caries, (c) marginal integrity, (d) surface texture, (e) restoration fracture, and (f) occlusal wear, rating with Alpha, Bravo and Charlie over an observation period up to 11years (68-139 months; median: 94.9±26.1 months). Data was statistically analyzed using the Kaplan-Meier estimation. RESULTS: Monolithic lithium disilicate occlusal onlays presented a 100% survival rate. Four restorations within one patient (3.9%) presented marginal discoloration, one after 60 and three after 108 months (all rated Bravo). One restoration (1%) showed a marginal crack formation (technical complication) after 120 months, rated Bravo. No biological complication, debonding or secondary caries could be found and tested periodontal parameters showed excellent results. SIGNIFICANCE: Based on the analyzed data up to 11years, monolithic occlusal onlays made of lithium disilicate ceramic can be considered as a reliable treatment option for full-mouth rehabilitations in patients with severe tooth wear.

Oral health-related impact profile in full-mouth restored patients with two different tooth-colored restoration materials.

OBJECTIVES: To analyze the change of oral health impact profile (OHIP) in patients with full-mouth rehabilitations due to moderate/severe tooth wear dependent on different restorative materials (ceramic/experimental CAD/CAM composite). MATERIALS AND METHODS: Twenty-nine healthy patients (15 male/14 female, age 44.6 ± 28.4 years) requiring full-mouth rehabilitation due to different degrees of tooth wear were instructed to fill the German version OHIP-G49 questionnaire before (baseline) and 30 days after prosthetic treatment with ceramic (n = 17) or experimental CAD/CAM composite (n = 12) restorations. Questions were divided into five dimensions: appearance, oral functions, psychosocial impact, linguistic limitations, and orofacial pain; changes between both OHIP-questionnaires for each question and patient were dissected by difference values, separately. Data were analyzed with the Kolmogorov-Smirnov, Wilcoxon's signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests (significance level p = 0.01). RESULTS: The appearance dimension showed the highest results (p < 0.001, 100% improvement with all values > 0); the linguistic limitations dimension presented the lowest improvement (p < 0.001). The other three dimensions were not statistically different. No statistical differences between the two materials depending on OHIP questionnaire results occurred. CONCLUSIONS: The esthetic appearance of the patients was influenced positively by full-mouth rehabilitation, irrespective of the material used. Improvements were also made in the parameters "toothache" and "problem of food intake." No statements could be made for the parameter "language." CLINICAL RELEVANCE: With an increasing number of patients with moderate/severe tooth wear, thorough knowledge about the improvement of OHIP is important. This information is advantageous for the consultation and handling of patients when complex treatments are planned.

Two-body wear of occlusal splint materials.

This study investigates the wear resistance of four different types of occlusal splint materials based on two-body wear simulations under wet and dry conditions. Twenty specimens of each splint material (Dentalon Plus, Orthoplast, Biocryl C, and Eclipse), each with a diameter of 16 mm and a thickness of 3 mm, were tested, half under wet and half under dry conditions. Each wear test was performed using a device called chewing simulator CS-4 (n=10; test load: 50 N; number of cycles: 10000, 20000, and 30000; continuous rinsing with 30°C water for wet conditions); the antagonists were simulated using steel balls. Wear was determined using a 3D laser scanner and a surface analysis program. To detect significant statistical differences, wear data after 10000; 20000; and 30000 cycles were compared using the Kruskal-Wallis test and the Mann-Whitney U-test. The level of significance was set at 5%. Significant differences were found between the groups of different materials tested under wet conditions (P<0.05), whereas no differences between them were found under dry conditions (P>0.05). No significant difference was found between the wet and dry conditions for all materials and cycles (P>0.05). For groups of different materials tested under wet conditions, the degree of volume loss generated in the Chewing Simulator CS-4 was found to differ significantly for different numbers of cycles. The presence of water had no effect on the volume loss in the different material groups that were tested.

Fracture resistance of posterior metal-free polymer crowns.

STATEMENT OF PROBLEM: Improved mechanical properties of contemporary composites has resulted in the extended use of composites for the restoration of posterior teeth. Although the indication of polymers was extended to metal-free individual crowns, the influence of tooth preparation design and cementation methods on the stability of these artificial crowns remains unknown. PURPOSE: This in vitro study evaluated the effect of axial tooth preparation design, occlusal dimension, and cementation technique on the fracture resistance of metal-free posterior Artglass crowns. MATERIAL AND METHODS: Seventy-two extracted human third molars, assigned to experimental groups by size, received standardized tooth preparation. Axial tooth preparation included an invasive approach with 1-mm deep shoulder and a less invasive 0.5-mm chamfer preparation, whereas occlusal reduction was either 0.5 mm or 1.3 mm. Artglass crowns that restored the original tooth contour were cemented with 3 cements: zinc phosphate cement (ZnP), glass ionomer cement (GIC), or a resinous cement in combination with a dentinal bonding agent. After 10,000 thermal cycles between 5 degrees C and 55 degrees C, artificial crowns were vertically loaded until compression to failure. Significant differences of fracture loads between experimental groups were assessed by paired Mann-Whitney U tests. RESULTS: Minimal fracture resistance for all combinations excluded 500 N. However, 9 of 24 Artglass crowns cemented with ZnP loosened after thermocycling. Adhesive cementation resulted in a significantly greater fracture resistance compared with GIC and ZnP (P=.02). Increased occlusal thickness (0.5 to 1.3 mm) resulted in greater stability, whereas a 1-mm deep shoulder tooth preparation did not improve durability compared with a 0.5-mm chamfer finishing line. CONCLUSION: A minimally invasive 0.5-mm axial chamfer tooth preparation combined with sufficient occlusal reduction and adhesive cementation recorded the greatest stability for posterior metal-free Artglass crowns.