The International Journal of Prosthodontics, 03/2018

Purpose: To evaluate the effects of sleeping with or without a maxillary mucosa-supported complete denture (CD) in edentulous patients wearing a mandibular fixed implant-supported CD on sleep quality, sleep bruxism (SB) activity, and signs of obstructive sleep apnea syndrome (OSAS). Materials and Methods: A total of 18 female patients with maxillary mucosa-supported CDs opposing mandibular fixed implant-supported CDs were selected and tested for sleep quality, SB activity, and signs of OSAS during one night while wearing the maxillary CD and another night without wearing it, with a washout period of 7 days in between. The validated Brazilian Portuguese versions of the Pittsburgh Sleep Quality Index (PSQI-BR), Sleep Assessment Questionnaire (SAQ), and Epworth Sleepiness Scale (ESSBR) were used to assess subjective sleep quality. Diagnosis of OSAS followed the American Academy of Sleep Medicine (AASM) guidelines and was confirmed with an objective and validated type 3 portable cardiorespiratory monitor (ApneaLink Plus v.9.00) by measuring the respiratory disturbance index (RDI). SB activity was assessed with a subjective self-report questionnaire and an objective and validated portable electromyographic device (BiteStrip). Results: The objective measurements of SB activity and the RDI showed significant reduction (ie, improvement) when patients did not wear the maxillary CD. The subjective measurements of sleep quality and self-reports of SB activity showed no significant differences between wearing and not wearing a maxillary CD. Conclusion: The present results have shown that not wearing a maxillary CD at night is preferable as far as SB and OSAS are concerned, but larger-scale studies are still needed.

Dystonia affecting the perioral and pharyngeal regions is called oromandibular dystonia (OMD). OMD can affect the jaw muscles and may cause trismus, mouth-closing disturbance, tooth wear/loss, and damage to the oral soft tissues and temporomandibular joint (TMJ). This case history reports a case of jaw-closing OMD accompanied by trismus-related TMJ osteoarthritis (OA). In the present case history, treatment for OMD was started as soon as the diagnosis of jaw-closing OMD was established, and dental treatment intervention for preventing its development or progression was considered at the same time.

Purpose: To demonstrate the influence of restorative material on the success of clinical bonding to zirconia. Materials and Methods: A total of 50 participants with a single implant received screw-retained restorations; ie, Lava Ultimate (LU) crowns extraorally bonded to zirconia abutments. After 1 year, lithium disilicate (LDS) was used as an alternative restorative material. These restorations were also followed for 1 year. Results: Forty LU restorations (80%) debonded within 1 year of clinical service, whereas no bonding failures occurred with LDS restorations. Conclusion: The choice of restorative material for single crowns luted to zirconia implant abutments strongly influences the incidence of bonding failures.

Purpose: To describe the restorative treatment profiles of long-span (> three units), implantsupported dental prostheses (LIDPs) prescribed in 27 private practices in the state of Victoria, Australia, during the period from January 1, 2005, to December 31, 2009. The restorative treatment profiles of these prostheses refer to the framework/veneering materials, number of prosthetic units/supporting implants, location in the oral cavity, retention methods, and cantilever designs. LIDPs refer to implant-supported prostheses of fixed or removable design; namely, fixed partial dentures (IFPDs), fixed complete dentures (IFCDs), removable partial dentures (IRPDs), and complete overdentures (IODs). Materials and Methods: Private dental practitioners providing implant treatment in Victoria, Australia, were invited to enroll in this study, which was conducted through a dental practice-based research network (the eviDent Foundation). The enrolled practitioners' clinical records of the implant treatments provided during the specified period were accessed for data collection. Descriptive statistics, cross-tabulations, and linear mixed models were conducted for data analyses. Results: During the study period, 627 LIDPs were prescribed to 556 patients by 18 general dentists and 5 prosthodontists. LIDPs were more common in the maxilla than in the mandible except in the case of IODs. Of the fixed prostheses, 60% replaced missing teeth in more than one sextant, 33% in the anterior sextant, and 7% in the posterior sextant. The average number of prosthetic units per implant was higher in mandibular compared to maxillary IFPDs/IFCDs (2.5 vs 1.9, respectively, P < .001). Cantilever pontic(s) were present in 68% of IFCDs (more often in the mandible than in the maxilla) compared to 28% of IFPDs (use of cantilever pontics was about the same in the maxilla and mandible). Screw retention was the most commonly reported retention method in IFPDs/IFCDs (95%). Locator attachment was used for the majority of IRPDs/IODs (83%). Conclusion: The clinicians enrolled in this study preferred fixed over removable LIDPs for partially dentate and maxillary edentulous cases. For mandibular edentulous patients, IODs were prescribed more often than IFCDs. A retrievable retention design was favored for IFPDs/IFCDs. IFPDs were predominantly metal-ceramic, and metal-acrylic designs were more popular for IFCDs.

Purpose: To investigate factors affecting sleep quality in maxillectomy patients after prosthetic rehabilitation and to determine the association between defect status and sleep quality. Materials and Methods: A total of 57 patients participated in this study. Sleep quality, general health, and oral health-related quality of life (OHRQoL) were evaluated. Results: Of the total sample, 89% had poor sleep quality. Early morning awakening and daytime sleepiness were the most common complaints. Conclusion: Defect status and the extent of neck dissection could affect sleep quality in these patients. Improvement of OHRQoL in patients with dentomaxillary prostheses may help improve sleep.

Prosthetic treatment for elderly patients is a challenge that addresses both patient- and technology-mediated dental concerns. This report describes the fabrication of a cobaltchromium crown without an impression using a digitized and scanned temporary crown to provide excellent integration.

Purpose: This study aimed (1) to geometrically evaluate areas of facial asymmetry in patients with two different types of maxillectomy defect compared to a control group, (2) to geometrically evaluate the effect of an obturator prosthesis on facial asymmetry, and (3) to investigate the correlation between three-dimensional (3D) deviation values and number of missing teeth. Materials and Methods: Facial data from 13 normal control participants and 26 participants with two types of maxillectomy defect (groups 1 and 2) were acquired with a noncontact 3D digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan using 3D evaluation software. Facial scans with and without obturator prostheses were also superimposed to evaluate the obturator effect. The correlation between 3D deviation values and number of missing teeth was also evaluated. Statistical analyses were performed. Results: Facial asymmetry was significantly different between the control group and each m axillectomy defect group (group 1: P < .0001 and P = .020 without and with obturator, respectively; group 2: P < .0001 for both conditions). There were no significant differences in asymmetry between groups 1 and 2 either without or with obturator (P = .457 and P = .980, respectively). There was a significant difference in the obturator effect between groups 1 and 2 (P = .038). 3D deviation values were positively correlated with number of missing teeth in group 1 (r = 0.594, P = .032), but not in group 2. Conclusion: A noncontact 3D digitizer and 3D deviation assessment were effective for analyzing facial data of maxillectomy patients. Obturators were effective for improving facial deformities in these patients.

Purpose: To compare vertical microgaps of milled titanium implant frameworks constructed using (1) direct model scanning (DMS) and (2) splinted impression (SIM) techniques. Materials and Methods: Three BioHorizon external hex implants were embedded in an epoxy resin model, and convenience samples of four identical frameworks in the DMS group and five in the SIM group were constructed. Implant-framework interfaces were scanned with a microcomputed tomography (CT) scanner, and the vertical microgap measured with one-screw and two-screw tests using CT analyzer (CTAn) software. Results: The mean maximum vertical microgap measured using the one-screw test was 13.25 μm in the DMS group and 72.40 μm in the SIM group (P < .0001). The mean maximum vertical microgap measured using the two-screw test was 10.5 μm in the DMS group and 36.2 μm in the SIM group (P = .0002). Conclusion: The milled titanium frameworks produced from direct scanning of implants had a smaller vertical microgap than frameworks produced from splinted impressions and master models.

Purpose: To evaluate the effect of color-vision deficiencies and type 1 diabetes mellitus (DM) on visual shade-matching ability. Materials and Methods: Four groups of participants were investigated: a control group (n = 68); a group with protanomalia (n = 10); a group with deuteranomalia (n = 19); and a group with type 1 DM (n = 13). Color vision was evaluated monocularly using the Ishihara test, Farnsworth-Munsell 100 hue (FM100H) test, Hardy Rand Rittler (HRR) test, and with an HMC Anomaloskop MR (Rayleigh and Moreland tests). The final exam was on a Toothguide Training Box (TTB) and consisted of 15 lightness-chroma-hue tasks. The color difference (ΔE*_ab) and the shade-matching score (ΣΔE*_ab) were computed, and the correct lightness (L*), chroma (C*), and hue (h*) selections were counted. The means and standard deviations for the ΣΔE*_ab, ΔE*_ab, L*, C*, h*, Ishihara, HRR, FM100H, and Rayleigh and Moreland tests were calculated. One-way analysis of variance (ANOVA) and post hoc Bonferroni test were used for statistical analyses and a comparison of means (α = .05). The data analyses were performed using SPSS 22.0 for Windows (IBM). Results: The control group selected the shade tab on the TTB significantly better (ΣΔE*ab = 31.57 ± 13.50) than the group with protanomalia (ΣΔE*_ab = 55.50 ± 12.36; P < .0001) and the group with deuteranomalia (ΣΔE*_ab = 59.18 ± 16.35; P < .0001), but not significantly better than the group with type 1 DM (ΣΔE*_ab = 39.43 ± 11.46; P = .368). The group with type 1 DM selected the shade tab on the TTB significantly better than the group with protanomalia (P = .038) and the group with deuteranomalia (P < .0001). Conclusion: Participants with color-vision deficiencies are less accurate at shade matching than the control group and the group with type 1 DM. Int

Purpose: To evaluate changes in distribution of teeth and in prosthodontic tooth replacement during an 11-year period in an adult population. Materials and Methods: Information on prosthetic status was collected from 4,288 participants aged 20 to 81 years at baseline in the Study of Health in Pomerania (SHIP-0) and from 2,244 participants aged 30 to 92 years who reappeared in the 11-year follow-up (SHIP-2). The tooth distribution per arch was classified into one of the six following classes: class 0 (edentulous), class 1 (one to three remaining teeth), class 2 (extended tooth-bounded space or extreme shortened dental arch), class 3 (small anterior space), class 4 (small posterior space with one or more missing premolars), or class 5 (functional dentition). Results: Longitudinally, the most pronounced change in class was the transition from class 1 to class 0 (maxilla: 54.5%, mandible: 58.3%). The percent change from other higher classes to lower classes ranged between 10% and 40%. In the same age groups of 40 to 79 years, the number of edentate arches was cut in half, with a corresponding increase in functional dentitions. The proportion of unrestored arches decreased in all classes. Double crown-retained partial removable dental prostheses (PRDPs) showed the highest increase (a 15% to 20% increase) at the expense of acrylic PRDPs in classes 1 and 2. In small spaces, the proportion of fixed dental prostheses (FDPs) also increased by 15% to 20%. Seven participants of SHIP-0 (0.16%) and 56 participants of SHIP-2 (2.5%) had dental implants. Conclusion: Similar age groups showed improvement in oral conditions. The proportion of higher-end restorations (FDPs and double crown-retained PRDPs), including the frequency of dental implants, increased.

Purpose: To determine the presence of burnout and psychiatric morbidity among prosthodontic residents and prosthodontists working in a maxillofacial prosthetic clinic and to compare these outcomes between those treating cancer patients and those not treating cancer patients. Materials and Methods: Two questionnaires were used: the Maslach Burnout Inventory (MBI) and the General Health Questionnaire (GHQ-12). MBI assesses the three components of burnout (emotional exhaustion, depersonalization, and personal accomplishment), and the GHQ-12 screens for nonpsychotic psychiatric morbidity. Six residents and four specialists involved in managing head and neck cancer patients were referred to as cancer clinicians to distinguish them from the specialists not involved in managing cancer patients (noncancer clinicians), who served as controls for other stressors within this work environment. Results: Twelve (86%) questionnaires were returned. There were no statistically significant (P = .89) differences between the cancer and noncancer clinicians from the GHQ-12 results; however, the cancer clinicians showed increased levels of exhaustion and depersonalization. These differences were not statistically significant (P = .36 and P = .41, respectively), but the effect sizes (Cohen's d) were moderate. For personal accomplishment both groups scored in the moderate burnout range, with the noncancer clinicians scoring higher. Conclusion: There is no doubt that the clinicians participating in this preliminary study were under some stress, and a moderate effect size indicated that cancer clinicians experience this to a greater extent.

Implant guide systems can be classified by their supporting structure as tooth-, mucosa-, or bone-supported. Mucosa-supported guides for fully edentulous arches show lower accuracy in implant placement because of errors in image registration and guide positioning. This article introduces the application of a novel microscrew system for computeraided implant surgery. This technique can markedly improve the accuracy of computerguided implant surgery in fully edentulous arches by eliminating errors from image fusion and guide positioning.

Purpose: To evaluate the fatigue and fracture resistance of anterior implant-supported and tooth-supported crowns made of different monolithic ceramics. Materials and Methods: Anterior crowns were fabricated of lithium disilicate or one of two zirconia ceramics and were tested as tooth-supported (reference) or as implant-supported crowns with chairside or labside (screw channel) procedures. After thermocycling and mechanical loading (TCML), crowns were loaded to fracture. Results: All crowns survived TCML. Implant-supported crowns (chairside and labside) showed higher fracture values than tooth-supported crowns. Fracture resistance was comparable or higher for zirconia than for lithium disilicate crowns. Conclusion: Implant-supported ceramic crowns may withstand clinical anterior loading forces.

Purpose: To evaluate surface treatments for chipping in order to avoid bonding problems between hybrid materials and composite resin and to determine the optimal surface treatment method during intraoral repair of restorations to achieve clinical success. Materials and Methods: A total of 96 samples were prepared from computer-aided design/computer-assisted manufactured (CAD/CAM) blocks: 48 polymer-infiltrated ceramic (PIC) and 48 resin nano-ceramic (RNC). Prior to application of the surface treatments, the two test groups were each divided into four subgroups: control group; hydrofluoric acid group; hydrofluoric acid with silane group; and air-abraded with silica-coated aluminum oxide (Al₂O₃) sand with silane group. Each subgroup contained 12 samples. A shear bond strength (SBS) test was performed after artificial aging (5,000 cycles, 5°C to 55°C). Results: For both types of ceramic used, all subgroups showed significantly higher SBS values than the control groups (P < .05). The highest SBS values for both types of ceramic were observed in the air-abraded with silica-coated Al₂O₃ particles group. Conclusion: Each of the surface treatment methods increased the SBS, with the most effective method being air abrasion with silica-coated Al₂O₃.

Aims: To evaluate the effects of complete denture (CD) quality and user satisfaction on the use of CDs provided by primary care services at 1 and 5 years postinsertion. Materials and Methods: A random sample of 233 individuals were evaluated regarding the use of maxillary and/or mandibular CDs at 1 and 5 years after insertion; at both time points, denture quality, integrity, and user satisfaction were measured. The covariates included age, gender, marital status, years of education, family income, past use of CD, time since maxillary teeth loss, mandibular ridge height, and frequency of return visits to the dentist after receiving the prostheses. The effect of the variables on the use of CDs throughout the period was estimated using logistic regression models with random effects in the intercept. Results: Overall, 64.9% and 64.1% of the participants were using their CD at 1 and 5 years, respectively. Of those who used the pair of prostheses at 5 years, 86.3% reported using them in the first evaluation. Use of CDs at 1 year was greater among users with some degree of education, higher satisfaction, and those whose CD had adequate stability and free functional space. Use of CDs at 5 years was greater in satisfied users and those with a stable CD. Conclusion: Denture quality and user satisfaction were associated with the use of CDs after 1 and 5 years. CD use was greater in individuals who had used it for 1 year, indicating greater abandonment in the first year than in other periods.

Prosthodontic oral rehabilitation procedures are time consuming and require efforts to maintain the confirmed maxillomandibular relationship. Several occlusal registrations and impressions are needed, and cross-mounting is performed to transfer the diagnostic wax-up to master working casts. The introduction of a digital workflow protocol reduces steps in the required process, and occlusal registrations with less deformation are used. The outcome is a maintained maxillomandibular position that is accurately and conveniently transferred.

Purpose: To assess the clinical performance of lithium disilicate single restorations on natural teeth. Materials and Methods: All patients who received lithium disilicate single restorations between 2009 and 2013 at the dental clinic of the University of Ferrara were recalled for clinical evaluation. A total of 43 partial and total restorations in 17 patients were evaluated from a minimum of 36 months follow-up to a maximum of 81 months follow-up, with a mean follow-up of 51 months. Results: The cumulative survival rate was 97.7%, and the cumulative success rate was 94.2%. Conclusion: Lithium disilicate can be successfully used for single-tooth restorations.

Purpose: A critical review of selected relevant publications assessed clinical efficacy and effectiveness of implant-assisted removable partial dentures (IARPDs) with implant survival and failure rates, biologic and technical complications, and maintenance and patient satisfaction after rehabilitation as outcomes. Materials and Methods: Screening of three databases (Medline [PubMed], Embase [OVID], and the Cochrane Library [CENTRAL]) and a manual search of related articles were performed. Reports on outcomes from human studies conducted between 1 January 1980 and 31 May 2016 were considered. A quality assessment of the identified full-text articles was performed to assess risk of bias and to evaluate heterogeneity. Results: Only nine studies were included, and all nine demonstrated high risk of bias. The mean observation period ranged from 1 to 10 years, and only four studies included at least one control group. The studies reported implant survival rates of 91.7% to 100%, abutment tooth survival rates of 79.2% to 100%, and prosthesis survival rates of 90% to 100%. Approximal peri-implant crestal bone level changes (ΔCBL) ranged from -0.17 to -2.2 mm. IARPDs were associated with a higher frequency of technical complications and maintenance interventions than biologic complications. Only two questionbased studies assessed patient satisfaction before and after treatment, and both reported marked improvement. A meta-analysis was not possible because of substantial heterogeneity in study design. Conclusion: Limited availability of robust publications related to the selected review topic precluded significant conclusions. Nonetheless, the preliminary assessment suggests that IARPDs are a simple and cost-effective approach to providing symmetric prosthesis support and stability, plus improved patient satisfaction.