OBJECTIVES:To evaluate clasp-retained removable partial dentures (C-RPDs) with a metal framework for survival, maintenance requirements, and biologic implications. METHOD AND MATERIALS:C-RPDs were retrospectively analyzed based on patient records. Treatment failure was defined as fracture of a framework component (metal base or connector) or loss of an abutment tooth. Other outcome variables included factors that might conceivably impact C-RPD survival (maxilla vs mandible, Kennedy classes, opposing dentitions, treatment by students vs certified dental practitioners), mobility and caries of abutment teeth (in relation to clasp designs), and maintenance requirements (relining, clasp or resin fractures). Differences were evaluated by appropriate statistical tests at the P ≤ .05 level. RESULTS:A total of 612 patients (339 men, 273 women) 60.0 ± 11.5 years old at delivery were included, covering 842 C-RPDs and a mean observation period of 42.1 ± 33.2 months. Kaplan-Meier C-RPD survival was 76.2% after 5 years and 49.5% after 10 years. Biologic complications (ie, loss of abutment teeth) accounted for the vast majority (95.6%) of C-RPD failures, and Kaplan-Meier C-RPD survival was significantly better in the mandible (P = .015). Some clasp designs contributed significantly to caries and removal of abutment teeth (both P .05). No other significant differences were noted. CONCLUSION:Tooth loss both emerges as the main cause of C-RPD failure and might be amenable to careful selection of clasp designs. Overall, better C-RPD survival should be expected in the mandible. A noncontributory role of Kennedy classes and opposing dentitions is tentatively suggested based on numerically heterogenous subgroups.

Im Rahmen einer zunehmend patientenzentrierten Versorgung stellt die mundgesundheitsbezogene Lebensqualität einen wichtigen Indikator dar, um die Beeinflussung der Patienten durch orale und orofaziale Beeinträchtigungen sowie einen Therapieerfolg bei zahnärztlichen Behandlungen zu messen. Im vorliegenden Beitrag wird ein Überblick über die Erhebung der mundgesundheitsbezogenen Lebensqualität gegeben, außerdem werden die Auswirkungen zahnärztlicher Therapien aufgezeigt.

BACKGROUND:Recently, recommendations were given for a new scoring of the Oral Health Impact Profile (OHIP). The original seven domain structure should be replaced by a four-dimensional scale.OBJECTIVES:To investigate the effect of dental prosthetic treatment on the seven domains and the four-dimensional scale of the OHIP-G49/53 questionnaire.METHODS:Seventy four patients were grouped according their pre- and post-treatment situation and the type of treatment they received. Patients completed the OHIP-G49/53 questionnaire before prosthetic treatment (T0), and at 1 week (T1), 3 months (T2) and 6 months (T3) after treatment. Treatment effects on the seven domains and the four dimensions of the OHIP scale were analysed, and the oral health-related quality of life (OHRQoL) was measured. Patients' expectations of their prosthetic treatment were also evaluated. Data were analysed using two-way Mixed ANOVA, regression analysis, and Cronbach's alpha test with a level of significance of α ≤ .017.RESULTS:OHRQoL significantly improved following prosthetic treatment compared with baseline. The largest improvement was found between T0 and T1 evaluations (all p ≤ .001). Unlike the seven-domain scale, the four OHIP dimensions demonstrated further significant improvements across the T1/T2/T3 evaluations (all p ≤ .017). Different pre-treatment findings had different treatment effects on the four OHIP dimensions and seven OHIP domains. Patients' expectations were mainly fulfilled.CONCLUSION:Compared with the seven-domain scale, the four dimensions showed significant follow-up changes, suggesting the four dimensions are suitable for evaluating treatment effects up to 6 months. Clinically meaningful effects of dental prosthetic treatment can be sensitively measured using the four-dimensional OHIP scale.

Objectives Different approaches to prosthodontic consultation, all involving a strong focus on shared decision-making, were analyzed from the perspective of patients by inter-group comparisons. No patient decision aid (PDA) was used in the control group, a paper-based PDA in test group 1, and a software-based PDA in test group 2. Materials and methods Seventy-five patients were prospectively randomized to the control group or a test group. All patients then rated the consultation on a questionnaire, six key items of which were analyzed, along with the time spent on each consultation. Results Overall satisfaction was highest in test group 2, with a significant difference from the control group ( p = 0.015). Test group 2 showed the most favorable ratings for all six questionnaire items, which invariably was significant compared to the control group ( p = 0.032). Test group 1 significantly differed from test group 2 based on two items (consultation was adequately intelligible: p = 0.011; consultation was adequately comprehensive: p = 0.034) but not from the control group based on any item ( p = 0.070). Conclusions Within the limitations of this study, the use of a software-based PDA, in particular, can be recommended based on patient satisfaction and was associated with the shortest sessions for consultation. Clinical relevance Patients are routinely faced with a wealth of information in dental offices and may be overwhelmed especially by prosthetic treatment options and decision requirements. Our findings shed some light on the nature of aids that may truly be helpful in the process of shared decision-making. Trial registration ClinicalTrials.gov.Identifier: ISRCTN11472465.

INTRODUCTION:At the moment, no commercial model solution is available for the individualisation of the dentition depending on the clinical case scenario. Furthermore, the realistic training of most restorative and prosthodontic procedures on a single dental study model is not possible. The aim of this study was the creation of a new training model to fill this gap.MATERIALS AND METHODS:Complete upper and lower jaw models were created based on existing scans and radiological data from a patient. All components for 100 complete models and 1128 teeth for the training were produced with a SLA-printer. Overall, 94 voluntary students attending the first and second preclinical course in prosthodontics tested the functionality of the model with three different tooth types against a standard dental study model and real teeth. After the training, the model was rated in a questionnaire.RESULTS:The production of the models and teeth was feasible. The overall rating of the different teeth was worse for type I (Ø 3.6 ± 1.1), significantly better for type II (Ø 2.5 ± 1.0) and type III (Ø 2.4 ± 1.0) than a standard typodont tooth (Ø 2.7 ± 1.1). The new model was rated significantly better overall (Ø 2.6 ± 1.0) than the standard training model (Ø 3.0 ± 1.1).CONCLUSIONS:The aim of this study was fulfilled. A superior training model was created with equivalent and better tooth types. The new teeth were outstanding in terms of cost-efficiency, appearance and feeling during preparation.

To define frailty in older cancer patients, the aim of this study was to assess the geriatric status and quality of life (QoL) aspects in patients suffering from recurrent/metastatic head and neck squamous cell carcinoma (r/m HNSCC) under palliative treatment. A comprehensive geriatric assessment (CGA) was performed on 21 r/m HNSCC patients at two defined assessments, and the QoL aspects and the impact of descriptive data were evaluated. The Kolmogorov–Smirnov test, Spearman’s rho correlation, and two-way mixed ANOVA were used for statistical analysis. All patients were found to be “frail”. Pain, fatigue, and the burden of illness were the highest-rated symptoms. Oral function and orofacial appearance were highly impaired. A significant impact of descriptive data on the CGA and QoL results was found (all p ≤ 0.05). Thus, the CGA results revealed high frailty, severe comorbidities, and high impairments in QoL aspects. The CGA and QoL results were negatively affected by the primary HNSCC treatment approach, the need for prosthetic treatment, and worse oral functional capacity. Therefore, frailty in r/m HNSCC patients seems to be multidimensional. The evaluation of the CGA and QoL aspects in r/m HNSCC patients can be recommended to detect special needs, organize aftercare, and improve the support for frail and vulnerable cancer patients to create a multidisciplinary treatment approach.

Narrow-diameter implants (NDIs) can be inserted instead of standard dental implants (SDIs) in sites with limited space and bone availability. The aim of this study was to evaluate the effect of implant diameter on peri-implant bone, attached mucosa, and on the associated probability of implant success and survival. The implants with progressive thread design and platform switching (Ankylos®, Dentsply Sirona; Mannheim, Germany) investigated were identified retrospectively and assigned to two groups based on their diameter: 3.5 mm (NDIs) and 4.5 mm (SDIs). Peri-implant bone loss was analyzed based on available radiographs. Descriptive and implant-associated factors were gathered from patient files. Data were statistically analyzed using the Kolmogorov–Smirnov–Lilliefors test and regression analyses. The level of significance was p ≤ 0.05. Results: In total, data for 415 implants in 194 patients were included in the study. Ten-year survival was 95.8% (NDIs) and 91.1% (SDIs). Implant diameter had no significant effect on peri-implant crestal bone loss (p = 0.098) or on the width of the attached gingiva (p = 0.052). Survival and success rates of NDIs were like or slightly better than those of SDIs. Because implant diameter had no effect on peri-implant tissue, NDIs can be recommended in selected cases.

Background: Preparation exercises represent an essential part in the study of dentistry. Digital grading software can be used for evaluation of prepared artificial teeth, which is mainly based on limited number of teeth and raters. In order to improve a standardized evaluation of preparations, the aim of this study was to assess the inter-rater reliability of a high number of teeth by different raters and, to evaluate specific preparation features. Methods: Therefore, a total of 1465 preparations of an artificial lower molar were evaluated with grades from 1 to 5 by four dentists out of three dental schools, and inter-rater reliability was calculated. A specific analysis program was used for objective evaluation of the preparation. Data were analyzed using the Kolmogorov-Smirnov test, Pearson chi-square test, and reliability analysis with a level of significance of p= 0.05. Results: The median value of all grades was 2.75 (IQR: 1.35). Lowest grade variance of 0.00 within the raters’ evaluations was observed in grade group 1. Grade variance of evaluations with grades 1 and 2 differed significantly from all the other grade groups (p≤0.003). The inter-rater reliability factor of all grade groups together was 0.958. Conclusion: Inter-rater reliability was very high, which indicates very good correlation of the given grades. The objective evaluation of preparation features has worsened with ascending grade groups. Significant differences within the grade groups indicate higher agreement when evaluating good preparations. The objective feature convergence and preparation angle, marginal width, and stump height have a crucial impact on evaluation.

Objectives: To compare the mechanical properties of different layers of multi-layered zirconia materials. Methods: 720 cylindric test plates were fabricated from four defined layers of three multilayered zirconia ceramics (IPS e.max ZirCAD Prime, Optimill Multilayer 3D; Ceramill zolid fx multilayer) and divided into two equal groups. One group underwent thermal cycling (5-55 degrees C, 10 000 cycles; "TC") and one did not ("no TC"), before density, flexural strength, Weibull modulus, and Vickers hardness were evaluated. EDX analysis was conducted using an additional cylinder of each material. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Statistical analysis was performed with Bonferroni correction (alpha < 0.001). Results: After aging, ZirCAD layer 4 showed the overall highest density (6.04 +/- 0.02 g/cm(3)), which was significantly higher than density of layer 4 of Optimill (6.02 +/- 0.06 g/cm(3)) and Ceramill (5.80 +/- 1.08 g/cm(3)) (both p < 0.001). Flexural strength of ZirCAD and Optimill increased consecutively after thermal aging. ZirCAD layer 4 had the overall highest flexural strength before and after artificial aging. After thermal cycling, the Weibull modulus ranged between 4.32 (ZirCAD layer 1) and 13.58 (Ceramill layer 4). ZirCAD had the overall highest Vickers hardness: in layer 1 (1579.18 +/- 47.14 HV) before aging, and in layer 2 (1607.1 +/- 149.71 HV) after aging. Flexural strength and Vickers hardness differed significantly between the four ZirCAD layers (p < 0.001). Thermal ageing had no significant impact on mechanical properties (p > 0.001). Significance: Mechanical properties were affected by plate position within the blank. When nesting a restoration within a multi-layered zirconia blank, the mechanical properties required should be considered. (C) 2022 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Medication-related osteonecrosis of the jaw (MRONJ) represents an adverse side effect of antiresorptive and antiangiogenic medications. It is associated with impaired quality of life, oral health, and oral function and can be classified into various stages. The purpose of this prospective clinical study is to evaluate the impact of stages I and II MRONJ on oral-health-related quality of life (OHRQoL) and related parameters. Patients’ OHRQoL, satisfaction with life, oral discomfort, and oral health were assessed using the German version of the Oral Health Impact Profile (OHIP-G49), visual analog scales (VAS), and Satisfaction with Life Scale (SWLS) at baseline (T0), 10 days (T1), and 3 months after treatment (T2) in 36 patients. Data were analyzed using Kolmogorov–Smirnov test, two-way mixed ANOVAs, and follow-up Mann–Whitney U tests. The impact of treatment effects on the original seven OHIP domain structures and the recently introduced four-dimensional OHIP structure were evaluated using linear regression analysis. Thirty-six patients received surgical MRONJ treatment. Before treatment, patients’ perceived OHRQoL, oral discomfort, oral health, and satisfaction with life were negatively affected by MRONJ. Surgical treatment significantly improved OHRQoL and related parameters (all p ≤ 0.012). This improvement was greater in patients with higher impairment at T0. OHRQoL and oral restrictions were still impaired after treatment in patients who needed prosthetic treatment. The four-dimensional structure revealed valuable information beyond the standard seven OHIP domains. Increased awareness of MRONJ risks and an interdisciplinary treatment approach for MRONJ patients are needed.

PURPOSE:To investigate the effect of missing teeth on patients' oral health-related quality of life (OHRQoL).MATERIALS AND METHODS:A total of 151 patients participated in this prospective bicenter clinical study (mean age: 64.7 ± 10.5 years; 71 women). Four subgroups were defined based on the number of missing teeth. OHRQoL was assessed using the German version of the Oral Health Impact Profile-49/53 (OHIP-G49/53) and visual analog scale (VAS) questionnaires. The effect of missing teeth on OHIP (total and by dimension) and VAS scores before and after prosthetic treatment was investigated at baseline (T0), 1 week (T1), and 3 months (T2) after prosthetic treatment. Scores were analyzed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests. Correlations were assessed using Spearman rho correlation. The level of significance was set at P = .05.RESULTS:Initial OHIP and VAS scores were highest for patients with 11 to 28 missing teeth. Scores improved among all groups between T0 and T1/T2. After prosthetic rehabilitation (T1), improvements in total OHIP scores were greatest for patients with no missing teeth or with 11 to 28 missing teeth. Patients with no missing teeth or with 1 to 4 missing teeth before treatment had the lowest posttreatment OHIP scores. Total OHIP scores among the groups were in the same value range (P > .185). No direct correlation was found between the VAS and total OHIP scores.CONCLUSION:OHIP and VAS scores for OHRQoL were associated with the number of missing teeth. Prosthetic treatment resulted in improved OHRQoL and oral function among all groups. The use of a VAS yielded additional detailed information.

Locator® and ball attachments are well-established systems to attach overdentures to two inter-foraminal implants. This study aimed to evaluate differences between the two systems regarding prosthetic maintenance and patients’ oral-health-related quality of life (OHRQoL). Dental records of patients with a mandibular implant-retained overdenture were retrospectively analyzed. Prosthetic maintenance measures involving the denture suprastructure and attachment matrix and patrix were analyzed. Furthermore, the Oral Health Impact Profile-G14 (OHIP-G14) was used to evaluate OHRQoL. Results were analyzed by means of Kaplan–Meier analysis and Student’s t- and log-rank tests. The records of 122 patients were evaluated. Kaplan–Meier survival analysis revealed a significant difference between ball attachments (Group B; n patients = 47) and Locator® attachments (Group L; n patients = 75) regarding the occurrence of denture fractures (p < 0.001) and events affecting the matrix (p = 0.028) and patrix (p = 0.030). Group L had a significantly lower total OHIP-G14 score than Group B (p = 0.002). The most common maintenance events were matrix-related and denture relining for both attachment systems. Group B required more maintenance measures than Group L. Moreover, patients in Group L had better OHRQoL than patients in Group B.

The aim of this study was to translate the Liverpool Oral Rehabilitation Questionnaire version 3 (LORQv3) into German and validate this version in order to assess oral-health-related quality of life (OHRQoL) among head and neck cancer patients. This study was conducted at a German university clinic among patients who had completed therapy for squamous cell carcinoma of the head and neck (HNSCC). The original English-language LORQv3 was translated into German according to the forward-backward approach. Validity and reliability were evaluated using further questionnaires related to OHRQoL and psychological impairments. Subgroups were built with reference to oral rehabilitation status and type of cancer therapy. Furthermore, OHRQoL was evaluated. Test-retest reliability was assessed by weighted kappa with a 10-14 day interval. Data were analysed by using Spearman's correlation and the following tests: Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney U and Cronbach's alpha. The level of significance was set at alpha = 0.05. Analysis of the LORQv3 evaluations revealed excellent Cronbach's alpha and high test-retest reliability. Construct validity were supported by the data. LORQv3 summary score and domains were significantly affected by status of oral rehabilitation (p = 0.003, p = 0.008, p = 0.024) and treatment approach (p < 0.001, p = 0.025, p = 0.035). The German version of the LORQv3 showed high reliability and validity and an impaired OHRQoL of HNSCC patients. It can therefore be recommended for the assessment of OHRQoL. (C) 2021 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

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.

Statement of problem. Screw loosening is a common problem in implant dentistry; however, information is sparse on the influence of different fluids on the screw threads. Purpose. The purpose of this in vitro study was to investigate the influence of 4 different fluids and agents (saliva, blood, chlorhexidine [CHX] gel, and special sealing silicone) on the preload force of abutment screws. Materials and methods. The test specimens (N=50) consisted of a thread sleeve resembling the implant, an abutment analog, and an abutment screw. The tightening of the screw with a torque wrench was performed in 5 steps (15 Ncm, 20 Ncm, 25 Ncm, 30 Ncm, and 35 Ncm). Each agent was applied in the lumen of the thread sleeve of 10 specimens. Ten dry thread sleeves served as the control. Comparisons between 2 independent groups were performed with the t test or Wilcoxon-Mann-Whitney test, as appropriate. The Bonferroni correction was used for multiple comparisons (alpha=.05). Results. Preload forces increased linearly with the applied tightening torque for dry implant lumina, as well as for saliva, blood, silicone, and CHX gel in the implant lumina or thread sleeves. In general, none of the tested agents resulted in significantly higher preload forces compared with the dry control. Conclusions. The agents investigated did not have any lubricant action on implant abutment screws.

BACKGROUND Telescopic prostheses are an evidence-based treatment modality, and conical zirconia crowns and electro-formed gold copings have been used for dentures supported by teeth and/or implants. PURPOSE We aimed to evaluate the survival rates of zirconia-based tooth/implant restorations. MATERIALS AND METHODS A total of 126 telescopic overdentures, all retained by conical zirconia crowns and electro-formed gold copings, were retrospectively evaluated and failures analyzed for abutment configurations. Survival rates and modifying factors were evaluated by Kaplan-Meier analysis, log-rank testing, and Cox regression analysis. RESULTS We evaluated observation periods of up to 11.5 years (mean: 45.25 ± 25.11 months). Five-year prosthesis survival was 96.9 ± 2.2% (95% CI: 92.6-100). Six dentures had been lost, and these failures were significantly associated with specific abutment configurations. CONCLUSIONS Within the limitations of this retrospective study, the concept of conical zirconia telescoping into electro-formed gold provides a viable alternative to other telescopic designs used for removable dental prostheses. The concept is well suited especially for tooth/implant-supported prosthetic rehabilitation.

The purpose of this study was to investigate the fracture resistance, flexural strength and Weibull modulus of an innovative CAD/CAM polymer and to compare its fracture resistance with that of glass ceramics. A total of 32 (n = 16 IPS e.max CAD (LIDI); n = 16 LuxaCam Composite (LUXA)) first mandibular molar crowns were fabricated and cemented onto metal dies by use of luting composite. Half of the specimens were loaded until fracture without prior artificial ageing. The other half were subjected to thermal (5°/55 °C) and mechanical (1,200,000 cycles, 80 N) cycling before fracture loading. Scanning electron microscopy was used to analyse fracture behaviour. A three-point bending test of the flexural strength of LUXA was performed according to ISO 6872:2008. Data were analysed by means of the Kolmogorov–Smirnov test, Mann–Whitney U-test (p < 0.05) and Weibull statistical analysis. Initial fracture resistance of LIDI was significantly higher than that of LUXA. However, the initial fracture resistance of LIDI decreased significantly after artificial ageing. After ageing, fracture resistance was 1050.29 ± 325.08 N for LUXA and 1250.09 ± 32.53 N for LIDI. Three-point bending test yielded a mean flexural strength value for LUXA of 145.28 ± 18.21 MPa and a Weibull modulus of m = 9.51. Polymer-based material tested in this study had a lower fracture resistance than that of the glass-ceramic material. Fracture resistance and flexural strength of LuxaCam Composite are sufficient for use in the first molar region. The mechanical properties of this innovative polymer-based material indicate it can be used in the first molar region as a suitable alternative to glass ceramics. Further clinical studies are required to confirm this.

The IPS e.max system by Ivoclar Vivadent, offering a variety of products and indications, is widely used for all-ceramic restorations. We analyzed the clinical track record of these products in daily clinical practice, associating their restorative survival rate with various parameters to define recommendations for long-term stability. A total of 1058 full-coverage crowns and fixed partial dentures (FPDs) were evaluated retrospectively over up to 66.48 (37.05 ± 18.4) months. All were made of IPS e.max Press, IPS e.max CAD, IPS e.max Ceram or IPS e.max ZirPress and had been delivered by a private dental practice within three years. Uses not recommended by the manufacturer were also deliberately included. The five-year cumulative survival was 94.22% (i.e., 94.69% or 90.58% for glass-ceramic crowns or FDPs and 100% or 90.06% for zirconia-based crowns or FDPs). Significantly superior outcomes emerged for conventional vs. adhesive cementation and for vital vs. non-vital abutment teeth, but not for recommended vs. non-recommended uses. Caution is required in restoring non-vital teeth, but the spectrum of recommended uses should generally be reconsidered and expanded, given our finding of high survival and success rates for IPS e.max ceramics, even for uses not currently recommended by the manufacturer.