The International Journal of Prosthodontics, 04/2017

Purpose: Edentulous patients benefit significantly from implant-supported overdenture prostheses. The purpose of this systematic review was to evaluate the cost-effectiveness of implant-supported overdentures (IODs) for edentulous patients. Materials and Methods: The search was limited to studies written in English and included an electronic and manual search through MEDLINE (Ovid, 1946 to November 2015), Embase (Ovid, 1966 to November 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (to November 2015), and PubMed (to November 2015). Two investigators extracted the data and assessed the studies independently. No meta-analysis was conducted due to the high heterogeneity within the literature. Results: Of the initial 583 selected articles, 10 studies involving 802 participants were included. Of these, 6 studies had a high risk of bias and the rest had an unclear risk of bias. Implant-supported prostheses were more cost-effective when compared to conventional dentures and fixed implant-supported prostheses. Overdentures supported by two implants and magnet attachment were reported as cost-effective. Conclusion: Implant-supported overdentures are a cost-effective treatment for edentulous patients. More clinical studies with appropriate scientific vigor are required to further assess the cost-effectiveness of implant-supported overdentures.

Purpose: The aim of this study was to determine whether dentists are able to discern and identify increases in occlusal vertical dimension (OVD) in dentate subjects without apparent loss of OVD. Materials and Methods: A total of 10 dentate subjects had mandibular overlays fabricated at 2-, 3-, 4-, and 5-mm openings of the anterior guide pin (AGP) of a semiadjustable articulator. Standardized frontal and profile photographs with subjects wearing each of the overlays were made. Photographs were presented in random order to 40 judges comprising 20 prosthodontists and 20 general dentists who were informed about the purpose of the study. Judges first rated the degree of facial naturalness on a visual analog scale (VAS) and then took a discriminatory sensory analysis test (triangle test) where they were required to correctly identify the image with no increase in OVD from a set of three images. Results: Mean VAS ratings for facial naturalness were inversely correlated with incremental increases in OVD, irrespective of the judge's background. Though subjects were rated less natural with incremental increases in OVD, only a 5-mm increase from baseline was clinically significant (P .05). For the triangle test, judges correctly identified the image with a 3-mm increase in OVD 57% of the time (P .582), irrespective of the judge's profession, sex, race, and years in practice, which were clinically insignificant. Conclusion: Increasing OVD by a 5-mm opening of the AGP of the articulator significantly decreased the judge's evaluation of facial naturalness. The ratings were more pronounced in female subjects than in male subjects. However, an increase in OVD of 3 mm was visually indistinguishable by the judges.

Purpose: The objective of this trial was to compare short-term patient preference for two mandibular complete denture (CD) fabrication techniques: neutral zone (NZ) and conventional (CV). Materials and Methods: A prospective, within-subject, randomized crossover trial was performed on a sample of 37 edentulous patients with complete denture experience. Two new sets of CDs were made for each patient, one set with a CV and one with a NZ mandibular denture. After consecutively wearing each set for at least 2 months after the last adjustment visit, patients indicated their preference (CV, NZ, or none). Associations and comparisons were made using the generalized linear model (GLM) and Fisher exact test between preference and sex, age, period of edentulousness, tissue quality, prosthodontic diagnostic index (PDI), and oral health-related quality of life (OHRQoL) differences of the two interventions assessed using the 20-item oral health impact profile (OHIP-20). Significance was determined at P = .05. Results: A total of 15 (40%) patients preferred NZ, 8 (22%) preferred CV dentures, and 14 (38%) had no preference. Although more women preferred NZ over CV dentures (50% versus 27%), difference in preference according to sex was not significant (P = .359). Neither was difference in preference and PDI scores significant (P = .603). Preference could not be strongly associated to period of edentulousness, age, tissue scores, and differences in OHIP-20 scores (P > .05), except for OHIP-20 scores and NZ preference (P .001). Better fit, comfort, and eating were reasons patients preferred a type of denture. These reasons were identified for both types of denture. Appearance and speech were not identified as reasons for a particular preference. Conclusion: Based on preference expressed by patients, there is no difference between NZ and CV mandibular dentures. Denture preference could not be related to patient variables over the study's time frame.

Purpose: The aim of this study was to assess the evidence of a correlation between the expertise of surgeons and the survival rate of dental implants. Materials and Methods: An electronic search in four databases (MEDLINE, EMBASE, SCOPUS, and the Cochrane Library) was performed for publications from their inception to May 2016 and was supplemented by manual searches. Prospective and retrospective cohorts were included if they met the following criteria: (1) the presence of an exposed group (inexperienced surgeons); and (2) the presence of a control group (experienced surgeons). Meta-analyses were performed to evaluate the effect of expertise on implant failure. Results: Of 609 potentially eligible articles, 8 were included in the qualitative analysis and 6 in the quantitative synthesis. Two meta-analyses were performed for different definitions of experienced surgeons. In the first meta-analysis, which included four retrospective comparative studies that defined experienced professionals as specialists, the experience of the surgeon did not significantly affect the implant failure rate (P = .54), with an odds ratio (OR) of 1.24 (95% CI, 0.62-2.48). In the second meta-analysis, which included two retrospective studies that defined experienced surgeons as professionals that had placed more than 50 implants, the expertise of the surgeon did significantly affect the implant failure rates (P = .0005), with an OR of 2.18 (95% CI, 1.40-3.39). Conclusion: The data from the included publications suggest that surgical experience did not significantly affect implant failure when considering experience based on specialty but were significantly affected when considering experience based on the number of implants placed. Further standardized prospective studies with a control of confounding factors are needed to clarify the role of surgical expertise on implant survival rates.

Purpose: The aim of this study was to explore the application of computer-aided design and rapid prototyping (CAD/RP) for removable partial denture (RPD) frameworks and evaluate the fitness of the technique for clinical application. Materials and Methods: Three-dimensional (3D) images of dentition defects were obtained using a lab scanner. The RPD frameworks were designed using commercial dental software and manufactured using selective laser melting (SLM). A total of 15 cases of RPD prostheses were selected, wherein each patient received two types of RPD frameworks, prepared by CAD/RP and investment casting. Primary evaluation of the CAD/RP framework was performed by visual inspection. The gap between the occlusal rest and the relevant rest seat was then replaced using silicone, and the specimens were observed and measured. Paired t test was used to compare the average thickness and distributed thickness between the CAD/RP and investment casting frameworks. Analysis of variance test was used to compare the difference in thickness among different zones. Results: The RPD framework was designed and directly manufactured using the SLM technique. CAD/ RP frameworks may meet the clinical requirements with satisfactory retention and stability and no undesired rotation. Although the average gap between the occlusal rest and the corresponding rest seat of the CAD/RP frameworks was slightly larger than that of the investment casting frameworks (P .05), it was acceptable for clinical application. Conclusion: RPD frameworks can be designed and fabricated directly using digital techniques with acceptable results in clinical application.

Purpose: The aim of this study was to investigate the relationship between type of endodontic treatment and choice of definitive restoration and to show the prevalence of endodontic treatment options according to patient age and type of tooth. Materials and Methods: Data were collected from the archive system of the School of Dentistry, National and Kapodistrian University of Athens in Athens, Greece. The sample included endodontically treated teeth being restored definitively at the time of data collection. Results: Statistically significant difference was found regarding the type of restoration between initial endodontic treatments and retreatments (P .001). Conclusion: Endodontic retreatment seemed to have a significant effect on the choice of definitive restoration of the tooth.

Purpose: The aim of this study was to conduct an overview of systematic reviews (SRs) related to aspects of the shortened dental arch (SDA) and its variants and critically appraise the methodologic quality of included SRs using the AMSTAR checklist. Materials and Methods: A comprehensive computerized search and a hand search of reference lists were conducted for SRs related to SDAs to identify publications from 2000 to 2016. All the present authors and a research assistant independently screened the results of the electronic searches using an eligibility form and extracted information using a specially designed prepiloted data extraction form. An 11-question AMSTAR checklist was completed for each included SR. Disputes were resolved by discussion between all researchers, and results were collated and interpreted. Results: For the period of 2007 to 2016, the search yielded nine SRs incorporating 228 related articles. The research questions for each SR differed but were related to SDAs, thus, the included articles were similar across SRs. Characteristics such as aims/objectives, study outcomes, and conclusions of the nine included SRs were compared. The AMSTAR evaluation indicated that five out of nine studies were of a high quality (used a rigorous methodology) and the remaining four were of medium quality. All nine SRs provided designs and characteristics of included studies. None of the SRs assessed publication bias. Conclusion: Of the nine SRs, seven drew positive conclusions regarding the SDA concept, finding it functionally sound, although some suggested that more high-quality primary studies are still needed. The AMSTAR calculation indicated that most included SRs had an acceptable methodologic quality, emphasizing the reliability of their results.

Purpose: This in vitro study evaluated the reliability of a surgical guide with regard to different levels of operator surgical experience and implant site. Materials and Methods: A stereolithographic surgical guide for epoxy resin mandibles with three edentulous molar sites was produced using a computer-aided design/computer-assisted manufacture (CAD/CAM) system. Two surgeons with and two surgeons without implant surgery experience placed implants in a model either using or not using the CAD/CAM surgical guide. Four groups were created: inexperienced surgeon without the guide (group 1); experienced surgeon without the guide (group 2); inexperienced surgeon with the guide (group 3); and experienced surgeon with the guide (group 4). Planned implants and placed implants were superimposed using digital software, and deviation parameters were calculated. Results: There were no significant differences in any of the deviation parameters between the groups when using the surgical guide. With respect to the implant sites, there were no significant differences among the groups in any parameter. Conclusion: Use of the CAD/CAM surgical guide reduced discrepancies among operators performing implant surgery regardless of their level of experience. Whether or not the guide was used, differences in the anterior-posterior implant site in the molar area did not affect the accuracy of implant placement.

Purpose: The aim of this study was to describe the histologic and histomorphometric features of a retrieved, functional endosseous zirconia implant in a human subject. Materials and Methods: A maxillary zirconia implant (ZV3) placed in a 52-year-old man was retrieved after 2 years of uncompromised service and prepared for light microscopic evaluation. Results: Histologic examination demonstrated good osseointegration. Bone contact measurements revealed a mean percentage of bone-to-implant contact of 55.8% (SD 3.8%). Conclusion: The histologic data provide further evidence of the potential of zirconia implants to osseointegrate to a similar degree as titanium in humans.

Intraoral digital impression is a viable alternative to conventional impression techniques and has been proven to be even more accurate than conventional materials. Nevertheless, there are cases in which the rheologic properties of conventional materials can be helpful. This article describes a method to overcome an insufficient sulcus-depth reading of intraoral scanners in challenging cases.

Purpose: The aim of this study was to evaluate the reliability and agreement of a new computerized planimetric method (CPM) for the measurement and assessment of plaque on all types of removable dental prostheses (RDPs). Materials and Methods: From a database containing 780 images taken following a standardized method for 65 RDPs, 55 images were randomly selected for image analysis. Adobe Photoshop software was used according to standard operating procedure (SOP) by one main examiner two times in different sessions, and one time by three additional examiners. To estimate the intra- and interexaminer reliability, intraclass correlation coefficient ICC(2,1) were used. Three parameters were used to estimate agreement: standard error of measurement (SEM), smallest detectable change at the 95% confidence level (SDC95%), and limits of agreement (LoA) according to the Bland-Altman method. Results: In all steps of the image analysis, both intra- and interexaminer reliability were excellent, with ICC(2,1) values > 0.85 at the 95% confidence level. The intra- and interexaminer values for both the SEMagreement and SDC95% were ≤ 6% and ≤ 17%, respectively. The Bland-Altman analysis revealed a satisfactory level of agreement. Conclusion: This study shows excellent inter- and intraexaminer reproducibility, a satisfactory level of examiner agreement, and acceptable measurement error. Furthermore, the method can be used with all types of RDPs. The CPM is more suitable for clinical research because of its objectivity, reliability, high level of standardization, and ability to detect and quantify small changes in plaque.

Purpose: To compare bleeding on probing (BoP), probing depth (PD; ≥ 4 mm), radiographic (peri-implant crestal bone loss [CBL]), and immunologic inflammatory (interleukin-1beta [IL-1β] and matrix metalloproteinase-9 [MMP-9]) parameters around dental implants with cementretained (CR) and screw-retained (SR) implant-supported crowns. Materials and Methods: Based on the mode of retention of the restoration, 51 patients were divided into two groups: Group 1, consisting of 26 single implants restored with CR crowns, and Group 2, consisting of 25 single implants restored with SR crowns. Peri-implant BoP, PD, and CBL were scored, and levels of IL-1β and MMP-9 in the peri-implant crevicular fluid (PICF) in both groups were measured in duplicate using enzyme-linked immunosorbent assay. Full-mouth mechanical debridement was performed biannually in both groups. Statistical analysis was performed using Kruskal-Wallis test with the significance level set at P .05. Results: The mean CBL among implants in groups 1 and 2 was 1.7 ± 0.5 mm and 1.7 ± 0.4 mm, respectively. There was no statistically significant difference in mean BoP, PD, and CBL among implants in both groups (P > .05). There was no statistically significant difference between groups 1 and 2 in the PICF levels of IL-1β (7.3 ± 0.5 and 7.2 ± 0.5, respectively) and MMP-9 (165 ± 9.4 and 182 ± 10.6, respectively) (P > .05). Conclusion: The mode of retention of implant-supported crowns does not appear to affect their clinical correlations with BoP, PD, CBL, and levels of IL-1β and MMP-9 in the PICF when zinc oxide eugenol cement is used.

Epidermolysis bullosa belongs to a group of genetic diseases that present with skin disorders and is characterized by generalized blister formation in response to mechanical trauma. This article reports on the management of a recessive dystrophic epidermolytic patient with four remaining periodontally compromised maxillary teeth. Treatment involved placement of four maxillary implants and use of computer-aided design/computerassisted manufacture techniques to fabricate a fixed full-arch implant-supported prosthesis. The prescribed dental treatment protocol led to a successful short-term prosthodontic outcome.

Different approaches ranging from veneers and crowns to employing the more conservative use of freehand resin composites have been proposed to correct esthetic problems caused by enamel fluorosis (EF). However, the protocol of mega-abrasion followed by microabrasion may be used as an alternative. It is less invasive and can minimize the unesthetic brown-to-whitish spots caused by EF. This article describes an easy and low-cost technique for managing enamel defects in a patient with severe enamel fluorosis.

Dental management of scleroderma patients is difficult and complicated because of compromised intraoral access. Physiotherapy may play an adjunctive and effective treatment role as described in a follow-up report on a previously documented case history.