The International Journal of Prosthodontics, 06/2011

Purpose: As more women are entering health professions, the health care system is becoming more feminized. This investigation evaluated gender differences in clinicians' treatment preferences and decision making in a complex treatment situation. Materials and Methods: A questionnaire was developed containing clinical cases and statements to assess practitioners' opinions on treatment of periodontally involved maxillary molars and implant therapy with sinus grafting. Data were analyzed with respect to the clinicians' sex, and an overall logistic regression was performed to further investigate possible influences of age, office location, and specialty. Results: Three hundred forty questionnaires were evaluated (response rate: 35.1%). The mean age of female respondents (37%) was 42 years, and the mean age of male respondents was 46 years. Significantly fewer women reported performing implant placement (35% vs 63%), sinus grafting (16% vs 43%), and periodontal surgery (57% vs 68%). Female practitioners tended to refer more patients to specialists. Participants favored sinus grafting more often for their spouses than for themselves. Apart from a preference for regenerative periodontal surgery among women, no gender differences were observed for treatment decisions or views on general statements related to implant preference, tooth maintenance, or conventional reconstructive therapies. Conclusions: With similar expert knowledge, treatment decisions were made irrespective of sex. While the majority of male care providers performed complex therapies themselves, female clinicians referred more patients to specialists.

Microtensile bond strengths of In-Ceram Alumina cores veneered with two ceramics after different numbers of firing cycles were evaluated. After In-Ceram Alumina cores were fabricated, they were veneered with either Vitadur Alpha or Vita VM7. A control group of each core-veneer combination was fired twice, and a second group was fired five times to induce thermal fatigue. Obtained microbars were subjected to microtensile bond strength tests. Data were analyzed using two-way analysis of variance. Microtensile bond strength values for Vita VM7 specimens were higher than those for Vitadur Alpha (P .001). Although the number of firing cycles revealed no change in bond strength, the veneering material proved to be an important factor.

Mastication was evaluated in subjects presenting extremely shortened dental arches (ESDAs) rehabilitated with mandibular free-end removable partial dentures (RPDs). Subjects were divided into four groups (n = 10): those with a complete dentition, those with ESDAs, and those with ESDAs who were rehabilitated with an RPD, who were evaluated both with and without their prostheses. Mastication was measured through masticatory performance, time, and ability. RPD wearers showed higher masticatory performance (P .01) and ability (P .001) and lower masticatory time (P .001) than when not wearing their prostheses as well as ESDA subjects who had not received RPD therapy. Those with a complete dentition showed the best results (P .001). It can be suggested that RPDs improve mastication in ESDA subjects but without achieving normal mastication levels.

The fixed implant-supported restoration of this mandibular surgical defect deliberately violated the principles of mandibular flexure, crown-to-implant ratio, and off-axis loading. A custom-made implant-mounted jig revealed no mandibular flexure in this patient, but crown-to-root ratios of up to 39:12 were unavoidable. The restoration has needed no maintenance for 14 years. This apparent success calls into question the blind application of prevailing clinical principles.

Purpose: The aims of this study were to develop a Croatian version of the Orofacial Esthetic Scale (OES) and to test its psychometric properties. Materials and Methods: The English version of the OES was translated into Croatian (forward-backward method). The original 11-point scale as well as a 5-point scale (1 = unsatisfactory, 5 = excellent) were used. Convergent validity was tested on 126 subjects, and discriminative validity was tested on the same subjects divided into four groups: esthetically normal patients (n = 25), esthetically impaired patients (n = 42), esthetically normal controls (n = 37), and esthetically impaired controls (n = 22). Test-retest reliability was tested on 43 subjects. Responsiveness was tested on 32 esthetically impaired patients who received prosthodontic treatment. Results: An additional explanation was added to the first two items of the OES. Convergent validity was confirmed by the association between OES scores and self-reported oral esthetics and three questions from the Oral Health Impact Profile related to esthetics (correlation coefficients ranged from 0.734 to 0.811, P .001). Discriminative validity showed the results as predicted. Test-retest reliability showed high intraclass correlation (0.79 to 0.95) and no significant differences between the two administrations of the 5-point OES scale (P > .05). The 11-point OES scale showed significant differences for questions 3 and 8 (P .01). Internal consistency showed high Cronbach α values (0.802 to 0.962). Responsiveness was confirmed by a significant difference between baseline and follow-up (P .001) and a high effect size. Conclusion: Psychometric properties of the Croatian version of the OES render the instrument suitable for the assessment of esthetics in Croatia. The authors recommend changing the first two items by adding the explanation that the questions are related to the lower third of the face and using the 5-point scale for rating.

Purpose: The aim of this study was to verify quality of life related to oral health and satisfaction with dentures. Conventional mandibular complete dentures were converted to overdentures retained by two implants with immediate loading (bar-clip system, n = 16). Materials and Methods: The Brazilian short version of the Oral Health Impact Profile (OHIP-14Br) was used to evaluate the impact of oral health on quality of life. Satisfaction with the prostheses was obtained by means of a questionnaire addressing satisfaction with the present prostheses and through use of a visual analog scale (VAS). Results: The results of the OHIP-14Br questionnaire were verified at 3 and 6 months after conversion from complete dentures to a mandibular overdenture. The satisfaction questionnaire for the mandibular prostheses obtained 43.75% satisfaction before conversion and 100% satisfaction at 1 week and 3 and 6 months after conversion. The satisfaction results of the prostheses, both maxillary and mandibular, were 68.75% before conversion, 93.75% at 1 week and 3 months after conversion, and 87.5% at 6 months. There was an immediate improvement in patients' satisfaction with the mandibular overdenture prostheses regarding stability and retention (Friedman test, P = .000) and quality of life (Friedman test, P = .001). Conclusion: The improvement seen justifies the immediate loading approach used in this study.

This preliminary clinical study aimed to identify the impact of two border-molding techniques (dentist-manipulated and patient-manipulated) on patient satisfaction, the occlusal force at denture dislodgment, and number of pressure sores. Salivary flow rate and residual ridge resorption were analyzed as covariates. Thirty-six edentulous patients in need of a relining of their existing maxillary denture were included. After relining, no significant influence of the border-molding technique on any of the variables investigated could be identified. It can be concluded that the impact of the border-molding technique on patient satisfaction and denture function probably has been overestimated in the past.

Purpose: The aim of this study was to describe the didactic and clinical undergraduate implant dentistry program of the Albert-Ludwigs University, Freiburg, Germany, with emphasis on the clinical implant experience. Materials and Methods: A detailed description of the implant curriculum at Albert-Ludwigs University is given with documented exemplary cases and additional flow charts. Results: All students participate in 28 hours of lectures and approximately 64 hours of seminars with hands-on courses and gain clinical experience. All undergraduate students are eligible to place and restore oral implants. Emphasis is placed on prosthetic-driven planning of implant positions, three-dimensional imaging, and computer-guided implant placement. Implant restorations performed by undergraduate students comprise single crowns and small multiunit fixed dental prostheses in partially edentulous posterior maxillae and anterior or posterior mandibles, implant-retained overdentures (snap attachment) in edentulous patients, and telescopic fixed-removable dental prostheses on remaining teeth and strategically placed additional implants. Over the past 2.5 years, 51 patients were treated with 97 dental implants placed by students in the undergraduate program. Seventy-one restorations were inserted: 60.6% single crowns, 7% fixed dental protheses, 21.1% overdentures, and 11.3% telescopic fixed-removable dental prostheses. The implant survival rate was 98.9%. Conclusions: Because survival rates for dental implants placed and restored by students are comparable to those of experienced dentists, oral implant dentistry should be implemented as part of the undergraduate dental curriculum.

The reliability and failure modes of molar crowns supported by three different implant-supported designs were tested according to the following groups: group 1, one standard-diameter implant (3.75 mm); group 2, one narrow-diameter implant (3 mm); and group 3, two narrow-diameter implants (3 mm). Loads were applied as mouth-motion cycles using a step-stress accelerated life-testing method. ß values for groups 1 and 3 (1.57 and 2.48, respectively) indicated that fatigue accelerated the failure of both groups, but not for group 2 (0.39). Abutment screw failure was the chief failure mode. Strength and reliability were significantly higher for groups 1 and 3 compared to group 2.

Hydrophilicity of unset impression materials underlies changes occurring during working time. Hence, the clinical application time when impression materials contact oral tissues after mixing may play a critical role in successful impressions. The aim of this study was to analyze the clinical time course of impression taking applying the single-step/double-mix technique. Application times of 86 impressions, comprising 265 prepared teeth and 46 implants, taken by 14 different clinicians at a university dental clinic were analyzed. The mean time from loading the impression tray until its final position in the patient's mouth (total application time) was 51.2 seconds; confidence intervals were 46.9 (lower limit) and 55.5 (upper limit). The number of registered teeth and implants did not influence the duration of impression taking. Related to wettability data, several polyvinyl siloxane impression materials show decreased hydrophilicity with respect to estimated application times. The authors suggest considering clinically relevant application times for impression taking in future in vitro studies on physicochemical characteristics of impression materials.

Purpose: Ceramic materials, first introduced in restorative dentistry in the late 18th century, offer a wide range of possibilities and exhibit esthetic properties. The last systematic reviews on the subject of ceramic inlays were published in 2003. All articles published up to 2001 were surveyed regarding the longevity, esthetic qualities, and postoperative discomfort associated with the use of ceramic inlays compared to other restorative materials. The present review aimed to establish the current state of the art. Materials and Methods: Using methods identical to those of previous reviews, the literature from 2001 up to and including 2009 was assessed. The scientific and methodologic qualities of all articles describing the use of ceramic inlays were established. Articles comparing the results of ceramic inlays to other types of inlays were then used to answer the hypotheses that there were no differences in longevity, postoperative sensitivity, or color match. Results: Three articles comparing the results of ceramic to other materials were analyzed further. No new reliable evidence was found to update the answer to the hypothesis that there was no difference in longevity, at least in the first year postoperative. The evidence found regarding postoperative discomfort backs the previous conclusion that there was no difference. New evidence found on color matching suggests that there is no significant difference in color match over assessment periods of up to 57 months. Conclusion: Current ceramic materials in inlay restorations seem to perform as well as other restorative options for selected properties during the first years after placement.

Purpose: This study tested the applicability of a multistage rating scale based on modified California Dental Association (CDA) criteria and the original criteria of the CDA for surface evaluation of all-ceramic restorations with the use of dental stone replicas, photographs, and scanning electron microscopy (SEM). Materials and Methods: Two examiners clinically evaluated 105 all-ceramic restoration units in the posterior region after a mean observation period of 42.2 months; the examiners employed the CDA criteria and a detailed six-stage rating scale. In addition, standardized photographs and gypsum stone and epoxy replicas based on impressions were analyzed blindly using the same rating scales and examiners. SEM images of gold-coated epoxy replicas enabled indirect ceramic surface evaluation, serving as the gold standard to control indirect evaluation and clinical findings. The Cohen kappa was applied to test for concordance; intraclass correlations and Spearman rank correlations were calculated. Results: Statistically significant rating correlations of the clinical situation, photographs, and stone replicas with the SEM photographs were generated from both evaluation systems. With the use of the multistage rating scale, the highest rating correlation was found for stone replica-SEM (r = 0.61, P .001), and the lowest for clinical photography-SEM (r = 0.5, P .001). Conclusions: A multistage rating scale based on modified CDA criteria is reliable for precise assessment of in vivo ceramic surface alterations. Stone replicas were found to be better-suited than photographs for the assessment of all-ceramic surface alterations and confirmation of clinical ratings.

Purpose: Recently, fiber-reinforced composite resin (FRC) has been introduced as a framework material for maxillofacial silicone prostheses. The purpose of this research was to study the tensile bond strength between a room temperature-polymerized maxillofacial silicone elastomer and a unidirectional FRC. Materials and Methods: Three different bonding agents were compared. Specimens were loaded in tension mode according to ISO 22401 in a universal testing device with a crosshead speed of 10 mm/min until bonding failure occurred. The influence of the surface characteristics (ground vs intact) was also studied. Results: The highest tensile bond strength was seen with Gold Platinum Primer A-330-G, followed by Sofreliner primer. One-way analysis of variance revealed that the surface treatment of the FRC and the adhesive used had a significant effect on tensile bond strength between silicone and FRC (P .05). Grinding enhanced adhesion, especially with Gold Platinum Primer A-330-G and Sofreliner primer. The fracture type also changed to more cohesive in nature. Conclusion: The FRC substructure can successfully be bonded to maxillofacial silicone elastomer by using primer containing methyl ethyl ketone and dichloromethane solvent. Bonding can be improved by roughening the FRC substrate via grinding.

Purpose: This study investigated how ribbed design features, including palatal rugae, may be used to significantly improve the structural performance of a maxillary denture under load. Materials and Methods: A computer-aided design model of a generic maxillary denture, incorporating various rib features, was created and imported into a finite element analysis program. The denture and ribbed features were assigned the material properties of standard denture acrylic resin, and load was applied in two different ways: the first simulating a three-point flexural bend of the posterior section and the second simulating loading of the entire palatal region. To investigate the combined use of ribbing and reinforcement, the same simulations were repeated with the ribbed features having a Young modulus two orders of magnitude greater than denture acrylic resin. For a prescribed load, total displacements of tracking nodes were compared to those of a control denture (without ribbing) to assess relative denture rigidity. Results: When subjected to flexural loading, an increase in rib depth was seen to result in a reduction of both the transverse displacement of the last molar and vertical displacement at the centerline. However, ribbed features assigned the material properties of denture acrylic resin require a depth that may impose on speech and bolus propulsion before significant improvements are observed. Conclusion: The use of ribbed features, when made from a significantly stiffer material (eg, fiber-reinforced polymer) and designed to mimic palatal rugae, offer an acceptable method of providing significant improvements in rigidity to a maxillary denture under flexural load.