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 post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of 3D-printed zirconia.

OBJECTIVE: To analyze the impact of different post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of additively manufactured zirconia. METHODS: Disc-shaped specimens (N = 100) were 3D-printed from 3 mol%-yttria-stabilized zirconia (material: LithaCon 3Y 210; printer: CeraFab 7500, Lithoz) and were cleaned with five different methods (n = 20): (A) 25 s of airbrushing with the dedicated cleaning solution (LithaSol 30®, Lithoz) and 1-week storage in a drying oven (40 °C); (B) 25 s airbrushing (LithaSol 30®) without drying oven; (C) 30 s ultrasonic bath (US) filled with Lithasol30®; (D) 300 s US filled with LithaSol 30®; (E) 30 s US filled with LithaSol 30® followed by 40 s of airbrushing (LithaSol 30®). After cleaning, the samples were sintered. Geometry, transmission, roughness (Ra, Rz), characteristic strengths (σ0), and Weibull moduli (m) were analyzed. Statistical analyses were performed using Kolmogorov-Smirnov-, t-, Kruskal-Wallis-, and Mann-Whitney-U-tests (α < 0.05). RESULTS: Short US (C) resulted in the thickest and widest samples. Highest transmission was found for US combined with airbrushing (E, p ≤ 0.004), followed by D and B (same range, p = 0.070). Roughness was lowest for US combined with airbrushing (E, p ≤ 0.039), followed by A and B (same range, p = 0.172). A (σ0 = 1030 MPa, m = 8.2), B (σ0 = 1165 MPa, m = 9.8), and E (σ0 = 1146 MPa, m = 8.3) were significantly stronger (p < 0.001) and substantially more reliable than C (σ0 = 480 MPa, m = 1.9) and D (σ0 = 486 MPa, m = 2.1). SIGNIFICANCE: For 3D-printed zirconia, cleaning strategy selection is important. Airbrushing (B) and short US combined with airbrushing (E) were most favorable regarding transmission, roughness, and strength. Ultrasonic cleaning alone was ineffective (short duration) or detrimental (long duration). Strategy E could be particularly promising for hollow or porous structures.

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.

Virtual reality: an effective tool for teaching root canal anatomy to undergraduate dental students - a preliminary study.

AIM: To introduce virtual reality (VR) into the endodontic curriculum for teaching root canal anatomy and to evaluate the effectiveness of this new method on third-year undergraduate students. METHODOLOGY: Extracted human teeth were digitized using a CBCT scan and converted into STL files. The corresponding files were either 3D printed or imported into a VR software program. Subsequently, forty-two third-year undergraduate dental students in preclinical training were asked to respond to a questionnaire analysing their ability to detect all the anatomic features of the replica teeth and their comprehension of the underlying root canal anatomy. The investigation was based on three different methods: two-dimensional radiography, CBCT scanning and VR simulation. Data were analysed using McNemar's and binomial test, and the level of significance was set to 0.05 (P = 0.05). RESULTS: Students reported that CBCT and VR allowed them to detect all anatomic features more than radiography (P < 0.001 - P = 0.049). Because it allowed improved comprehension of root canal anatomy, the VR simulation was considered better than CBCT scanning and radiography. Most of the students adapted well to the VR simulation. CONCLUSIONS: Dental students greatly appreciated the integration of VR simulation into the endodontic curriculum. From a didactic point of view, VR has considerable advantages over three-dimensional reconstructions and two-dimensional radiographs when teaching root canal anatomy.

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.

Historical development of root analogue implants: a review of published papers.

The timetable for placing a dental implant can be crucial in the reduction of resorption of the socket after an extraction. The association of immediate implantation with an implant that copies the anatomy of the extracted root seems to add benefits in limiting the hard and soft tissue changes that may occur. The purpose of this paper is to provide an overview of the historical development of all types of root analogue implants from their beginning to the present day. To our knowledge the first individualised ones were described in 1969. Later, the use of titanium instead of the polymers that were used to start with offered better bony integration, and showed that the selection of materials was a key factor in their success. Root analogue implants made from zirconia were also described when attempts were being made to improve aesthetics in the anterior regions. The more recent introduction of digital technology such as DICOM has allowed the fabrication of these implants in less time, and the combination with digital diagnostic options such as cone-beam computed tomography facilitated the fabrication of some types of implants before extraction that could be inserted immediately into the alveolar socket with optimal and safe 3-dimensional positioning. Currently digital planning allows the clinician to design the ideal implant and abutment, which reduces the need for tissue grafting in the surgical phase and gingival conditioning in the prosthetic phase.

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.

Impact of Recently Developed Universal Adhesives on Tensile Bond Strength to Computer-aided Design/Manufacturing Ceramics.

OBJECTIVES: The aim of this investigation was to test the tensile bond strength (TBS) between different computer-aided-design/manufacturing (CAD/CAM) ceramics after conditioning using different universal adhesive systems and resin composite cement. METHODS AND MATERIALS: Substrates of four CAD/CAM ceramics-1) VITABLOCS Mark II, 2) Initial LRF, 3) Celtra Duo, and 4) IPS e.max CAD (N=648, n=162)-were fabricated. VITABLOCS Mark II and Initial LRF were etched using 9% hydrofluoric acid for 60 seconds, Celtra Duo for 30 seconds, and IPS e.max CAD for 20 seconds. Substrates for conditioning using Monobond Etch & Prime were untreated. The following adhesive systems were used: All-Bond Universal (ABU), Clearfil Universal Bond (CUB), G-Multi Primer (GMP), iBond Universal (IBU), Monobond Etch & Prime (MEP), Monobond Plus (MBP), One Coat 7 Universal (OCU), Prime&Bond Active (PBA), and Scotchbond Universal (SBU). Conditioned substrates were bonded using a resin composite cement (Variolink Esthetic DC), thermal cycled (20,000×, 5°C/55°C), and TBS was measured using a universal testing machine. Data were analyzed using univariate analysis with partial eta-squared, Kolmogorov-Smirnov, Kruskal-Wallis, Mann-Whitney U, and Spearman-Rho tests (α=0.05). RESULTS: ABU, MEP, and MBP obtained the significantly highest TBS, while CUB, IBU, and OCO resulted in the lowest, regardless of the CAD/CAM ceramic. SBU showed varying TBS results depending on the CAD/CAM ceramic used. ABU, MEP, and MBP showed no impact of CAD/CAM ceramic on TBS values. ABU, GMP, MEP, and MBP showed predominantly cohesive failure types in luting composite, while CUB and OCU demonstrated adhesive failure types.

Systematic development of esthetics and function in a young patient with maxillary dental aplasia.

OBJECTIVES: Full-arch rehabilitations in young patients suffering from dental agenesis should compensate for the reduced vertical dimension of occlusion and restore both esthetics and function at minimal biological cost. This requires precise planning and maximum patient compliance during the preprosthetic phase. The pretreatment period with tooth-colored splints promotes a predictable outcome of the final restorations. Clinical considerations: Thanks to better restorative materials and adhesive techniques and increased knowledge of how to preserve sound tooth structures, prosthetic dentistry has increasingly turned toward minimally invasive procedures. The present clinical case documents a minimally/non-invasive maxillary full-arch rehabilitation of an agenesis patient with multiple dental aplasia, primary tooth persistence, and deficits in bone growth. The patient was pretreated with a tooth-colored CAD/CAM polycarbonate splint. Adequate esthetics and function were achieved by two zirconia-based single-wing adhesive fixed dental prostheses to replace the upper lateral incisors, lithium disilicate ceramic partial crowns for the posterior regions, and two feldspathic veneers for the upper central incisors. CONCLUSIONS: Non-invasive pretreatment with a removable tooth-colored splint realizes the treatment goal simply and safely, reduces treatment time, increases predictability, and facilitates the transfer of the prototype to the final restorations. New restorative options permit the minimally invasive treatment of such patients. CLINICAL SIGNIFICANCE: A pretreatment with a removable tooth-colored splint offers a simple and safe way to define the treatment goal, reduces treatment time, increases predictability, and facilitates the transfer of the results to the final restorations even in complex cases. New restorative options permit minimally invasive treatments of young patients with multiple dental agenesis.

Reproducibility of sonographic soft-tissue measurement of the head and neck.

OBJECTIVE: Effectiveness of manual lymphatic drainage in the head and neck region is not supported by evidence-based data. The objective of this study was to verify if the chosen locations enable the measurement of reproducible skin-to-bone distances without marking the measurement place, providing, therefore, adequate sites for long-term follow-up of the soft tissue width. METHODS: Sonographic measurement was performed in 21 healthy volunteers by the same examiner on three consecutive days. Skin-to-bone distance was measured each time at five defined locations over the mandible and hyoid. RESULTS: The average deviation caused by consecutive measurements was estimated to be between 0.7 and 1.2 mm for the different locations. When comparing right-to-left average skin-to-bone distances, differences of a maximum of 1 mm were measured. CONCLUSIONS: Sonographic soft tissue width, as measured by the skin-to-bone distance at defined sites of the head and neck, is highly reproducible in healthy adults without marking these measurement sites. These regions can, therefore, be used to quantify the effectiveness of manual lymphatic drainage for head and neck lymphedema by monitoring the course of the skin-to-bone distance.

Early rehabilitation of head-neck edema after curative surgery for orofacial tumors.

OBJECTIVE: To evaluate a rehabilitative program for postoperative head-neck edema. DESIGN: Eleven patients completed the study. A series of ten manual lymphatic drainage were initiated and completed early after surgery. On discharge from the hospital, the patients wore "made-to-measure" or customized compression garments for the next several weeks. Tape measurements and sonographic evaluation of the soft-tissue width were used to quantify the extent of the swelling. RESULTS: After 6 wk of therapy, the patients exhibited a statistically significant (P < 0.05; Wilcoxon's test) remission; the remission continued in eight patients who were measured at 12+/-3 wk. CONCLUSIONS: This initial trial demonstrates that sequential therapy of manual lymphatic drainage and compression garments can significantly reduce early postoperative edema after curative surgery for orofacial tumors. The outcome can be quantified by comparing the course of distances between the defined anatomic marks and by sonographic evaluation of soft-tissue width. This pilot study encourages that more controlled, randomized studies, with larger numbers of patients, be conducted to verify these results.

Group exercise improves patient compliance in mild to moderate hypertension.

One of the major problems of both pharmacological and non-pharmacological treatment is compliance of the patient. We attempted to reduce compliance problems by using group exercise in hypertensive patients. A group of 29 hypertensive patients (aged 54 +/- 10 years) met weekly for nearly 2 years. Each session (90-120 min) comprised four parts: endurance training, gymnastics and relaxation, education and a discussion of related problems such as nutrition and lifestyle. There was a significant decrease in systolic (9%) and diastolic (6%) blood pressures at rest and during exercise (systolic 12%), and an increased maximal work load (18%). In addition, drug treatment was substantially reduced (reduced in 56% of patients abandoned in 10% of patients). Cholesterol levels were reduced by 18%, although, during a 6-10 day nutritional report, fat made up 40% of the total calorific intake, indicating the need for individualized dietary advice. The major goal was to improve compliance and increase non-pharmacological treatment, exercise being a minor consideration which may have relevance for the treatment of hypertension.

[Optimal long-term control of arterial hypertension. Experiences with ambulatory, sports-oriented groups of patients with hypertension]. / Optimierte Langzeitkontrolle der arteriellen Hypertonie. Erfahrungen mit ambulanten, sportorientierten Hochdruckgruppen.

Out-patient groups of hypertensives were organized in an effort to improve long-term treatment results with greater attention to general measures and to increase compliance. Under supervision of a doctor and a physiotherapist 45 patients (aged 54 +/- 10 years) with mild or moderately severe hypertension were enrolled in a sports training programme after thorough examination. At the same time they were given advice and instructions on self-measurement of blood pressure, diet, medication, general life style and relaxation techniques. In the first 20 patients (observation period of more than one year) a significant reduction in both resting (systolic of -9%) and exercise (systolic of -12%) blood pressures was noted. At the same time exercise tolerance was raised (+18%), while body-weight and total cholesterol concentrations were lowered. It was possible to reduce drug dosage in seven patients, in three more it was discontinued. Left-ventricular wall thickness fell slightly but not significantly. There were no complications. It is concluded that group therapy with sport as a vehicle and advice on general life style are satisfactory means for controlling hypertension and achieve better compliance.

Possible interaction of platelets and adrenaline in the early phase of myocardial infarction.

It is known that in most cases of transmural acute myocardial infarction a platelet clot originates within a coronary artery. In acute myocardial infarction patients increased levels of the plasma catecholamines adrenaline and noradrenaline as well as the platelet release proteins platelet factor 4 and beta-thromboglobulin have been reported. In this study, significantly higher values were found of platelet factor 4 (P less than 0.0001) and beta-thromboglobulin (P less than 0.002) in 17 acute myocardial infarction patients as compared to 17 control patients (on intensive care due to non-cardiac disorders), while the plasma levels of adrenaline and noradrenaline were not different. Positive correlations were obtained between the two catecholamines and the platelet products in the control group and between adrenaline and both platelet factor 4 (r = 0.715, P less than 0.01) and beta-thromboglobulin (r = 0.547, P less than 0.05) in the acute myocardial infarction patients. The data suggest that a stimulation of the platelets by adrenaline may facilitate in vitro activation during sampling in patients with high catecholamine load. On the other hand, a "preactivation" of the platelets by an increase of adrenaline might be of significance for thrombus formation in acute myocardial infarction.