Factors Influencing Removable Partial Denture Patient-Reported Outcomes of Quality of Life and Satisfaction: A Systematic Review.

PURPOSE: A systematic search of the literature was performed to identify and characterize articles reporting the influence of removable partial denture (RPD) therapy on satisfaction and quality of life (QoL). MATERIALS AND METHODS: The literature search for relevant articles published between January 1983 and March 30, 2013 was conducted using keyword searches of electronic databases and complimentary hand searches. The search strategy included the following keyword combinations (MeSH and free-text terms): fail, complication, surviv*, longevity, outcome, patient satisfaction or QoL, and denture or prosthes*, and partial and removable. Based on inclusion and exclusion criteria, articles focused on the effect of RPD therapy were reviewed and classified according to Strength-of-Recommendation Taxonomy (SORT) criteria. RESULTS: The combined search identified 997 publications; 198 duplicates were identified and removed, leaving 799 references for further evaluation. After abstract review, 209 articles were selected and read; 18 reports representing findings from 4002 patients were included. While two studies were prospective comparative investigations, the majority of studies represented cross-sectional and retrospective studies. Different instruments were used to measure oral health-quality of life (OHQoL) and satisfaction. Several investigations reported a significant association of satisfaction and QoL with either (a) age of the patient, (b) number of occluding dental units replaced, (c) replacement of anterior teeth, and (d) nature of the opposing arch. CONCLUSIONS: A paucity of detailed investigations concerning outcomes of RPD therapy was noted. Improvement in OHQoL or satisfaction following provision of RPDs was not consistently reported. There is little evidence supporting any association between patient-reported QoL or satisfaction with technical or biological parameters of therapy. Therapeutic success of tooth replacement using RPDs should be carefully considered and compared with alternatives.

Efficacy of Alveolar Vertical Distraction Osteogenesis and Autogenous Bone Grafting for Dental Implants: Systematic Review and Meta-Analysis.

PURPOSE: The aim of this study was to assess the efficacy of alveolar vertical distraction osteogenesis and autogenous bone grafting in terms of bone gain, bone resorption, and implant survival and success rates and investigate the relationship between bone gain and resorption after alveolar vertical distraction osteogenesis. MATERIALS AND METHODS: A systematic search was done using MEDLINE, EMBASE, the Cochrane Library, and KoreaMed from inception to April 30, 2014. Supplementary manual searches of published full-text articles were also performed. RESULTS: Searches of four electronic databases and manual searches resulted in 1,538 articles. After selection, four studies were included in the systematic review and meta-analysis. The difference in bone gain at the end of distraction or bone grafting was statistically significant (weighted mean difference [WMD] 1.86, 95% CI 0.03 to 3.69, P = .05; heterogeneity: I(2) = 78%, P = .01). However, there was not a statistically significant difference between alveolar distraction osteogenesis and onlay bone grafting (WMD 0.30, 95% CI -0.99 to 1.59, P = .065). Bone resorption between the end of treatment and the time of implant placement was not statistically significant (WMD -0.12, 95% CI -1.10 to 0.85, P = .80; heterogeneity: I(2) = 78%, P = .01). A simple equation related to bone gain and resorption after alveolar vertical distraction was induced from these results. CONCLUSION: There was not a statistically significant difference between alveolar distraction osteogenesis and onlay bone grafting in terms of bone gain and bone resorption.

Factors influencing dental students' specialty choice: a survey of ten graduating classes at one institution.

The aim of this study was to survey ten graduating classes at Harvard School of Dental Medicine regarding students' specialty choice and factors influencing that choice. Students were surveyed once in 2008 (for the Classes of 2007-11) and again in 2013 (for the Classes of 2012-16). A prior article reported results regarding students' interest in and experiences with prosthodontics; this article presents results regarding their interest in all dental specialties and factors influencing those interests. Of a total 176 students in the Classes of 2012-16, 143 responded to the survey, for a response rate of 81%, compared to a 95% response rate (167 of total 176 students) for the Classes of 2007-11. The results showed that orthodontics was the most popular specialty choice, followed by oral and maxillofacial surgery. From the 2008 to the 2013 survey groups, there was an increase in the percentages of students planning to pursue oral and maxillofacial surgery, pediatric dentistry, and postdoctoral general dentistry. The educational debt these students expected to accrue by graduation also increased. The largest percentage of students chose "enjoyment of providing the specialty service" as the factor most influencing their specialty choice. "Prior dental school experience" and "faculty influence" were greater influences for students pursuing specialties than those pursuing postdoctoral general dentistry. Increased interest in particular disciplines may be driven by high debt burdens students face upon graduation. Factors related to mentoring especially influenced students pursuing specialties, demonstrating the importance of student experiences outside direct patient care for exposure to the work of specialists beyond the scope of predoctoral training. This finding suggests that dental schools should increase mentoring efforts to help students make career decisions based not on financial burden but rather on personal interest in the specialty, which is likely to have a more satisfying result for them in the long run.

Comparative study of the shear bond strength of various veneering materials on grade II commercially pure titanium.

PURPOSE: To compare the shear bond strength of various veneering materials to grade II commercially pure titanium (CP-Ti). MATERIALS AND METHODS: Thirty specimens of CP-Ti disc with 9 mm diameter and 10 mm height were divided into three experimental groups. Each group was bonded to heat-polymerized acrylic resin (Lucitone 199), porcelain (Triceram), and indirect composite (Sinfony) with 7 mm diameter and 2 mm height. For the control group (n=10), Lucitone 199 were applied on type IV gold alloy castings. All samples were thermocycled for 5000 cycles in 5-55℃ water. The maximum shear bond strength (MPa) was measured with a Universal Testing Machine. After the shear bond strength test, the failure mode was assessed with an optic microscope and a scanning electron microscope. Statistical analysis was carried out with a Kruskal-Wallis Test and Mann-Whitney Test. RESULTS: The mean shear bond strength and standard deviations for experimental groups were as follows: Ti-Lucitone 199 (12.11 ± 4.44 MPa); Ti-Triceram (11.09 ± 1.66 MPa); Ti-Sinfony (4.32 ± 0.64 MPa). All of these experimental groups showed lower shear bond strength than the control group (16.14 ± 1.89 MPa). However, there was no statistically significant difference between the Ti-Lucitone 199 group and the control group, and the Ti-Lucitone 199 group and the Ti-Triceram group. Most of the failure patterns in all experimental groups were adhesive failures. CONCLUSION: The shear bond strength of veneering materials such as heat-polymerized acrylic resin, porcelain, and indirect composite to CP-Ti was compatible to that of heatpolymerized acrylic resin to cast gold alloy.

Dental students' perceptions of and experiences with prosthodontics: ten graduating classes at one institution.

It is important for members of the dental specialties to understand what motivates students to enter the specialty in order to ensure its continuing development and ability to meet patient needs. The aim of this study was to compare ten graduating classes at Harvard School of Dental Medicine (HSDM) regarding students' experiences with and perceptions of prosthodontics and factors influencing those interested in pursuing prosthodontics as a specialty. In 2013, HSDM students in the classes of 2012-16 were surveyed, achieving a response rate of 81%. Survey questions sought information regarding specialty choice, factors influencing the choice, student experiences with prosthodontics, and student perceptions of the dental disciplines. Responses were compared to those from a prior study of the HSDM classes of 2007-11. The responses showed a decrease in negative student experiences with prosthodontics. The students regarded prosthodontics highly for its impact on patient quality of life; however, students interested in pursuing prosthodontics as a specialty decreased. All students said provider enjoyment was most important in choice of specialty. Cost of program, patient type, and program location were factors that especially influenced students interested in prosthodontics. The improved student experiences with and perspectives on prosthodontics may be a result of a curriculum change that led to more prosthodontics procedures and case completions by students. The fall in students interested in prosthodontics may have resulted from prosthodontic faculty transitions that occurred when the survey was conducted, as well as large debt burdens in spite of the fact that prosthodontists' earnings are among the highest in dentistry. Faculty must educate and mentor students about the realities of the profession, provide positive learning experiences in the field, and encourage students who enjoy prosthodontics to pursue specialty training.

Measurement of total occlusal convergence of 3 different tooth preparations in 4 different planes by dental students.

STATEMENT OF PROBLEM: Total occlusal convergence of crown preparation is an important didactic and clinical concept in dental education. PURPOSE: The purpose of this study was to compare the discrepancy between the total occlusal convergence of dental students' typodont crown preparations and the ideal range (4 to 10 degrees) in 3 different regions of the mouth and in 4 different planes of the teeth. MATERIAL AND METHODS: The dental students of the Class of 2012 at Harvard School of Dental Medicine were asked to prepare typodont teeth for crowns on 3 different teeth, the maxillary left central incisor (ceramic), mandibular left first molar (complete metal), and mandibular left first premolar (metal ceramic), during their third year preclinical summative examination and the Comprehensive Clinical Examination in their fourth year. Eighteen students prepared 3 teeth in their third and fourth years, whereas 19 students participated only in their fourth year, for a total of 55 sets of 3 teeth. By using custom fit die bases to reproduce the position, a novel procedure of measuring each tooth was accomplished in 4 different planes: the faciolingual, mesiodistal, mesiofacial-distolingual, and mesiolingual-distofacial. The total occlusal convergence of each image was measured with a computer screen protractor. The gingival 2 mm of the axial wall was used to determine the taper of each wall. Linear mixed model analysis was used to estimate and compare the total occlusal convergences of different teeth and planes (α=.05). Bonferroni corrections were used to adjust for post hoc multiple comparisons. RESULTS: The mean total occlusal convergence varied by tooth and plane (2-way interaction; P<.001). For the first molar, dental students excessively tapered in all 4 planes; the model-predicted 99% CIs for the total occlusal convergence were as follows: faciolingual (12.7, 19.4), mesiodistal (14.0, 19.3), mesiofacial-distolingual (13,4, 19.4), and mesiolingual-distofacial (13.7, 19.1). For the central incisor, 99% CIs for the total occlusal convergence were (15.9, 24.4) for the faciolingual measurement, providing strong evidence of excessive tapering, and (4.1, 8.0) for the mesiodistal measurement, which was within the ideal total occlusal convergence range. The mesiofacial-distolingual and mesiolingual-distofacial planes in the central incisor and all 4 planes in the first premolar had mean total occlusal convergences that exceeded 10 degrees; however, excessive tapering could not be statistically established, because their CIs included values within the ideal range. CONCLUSIONS: The present study found significant evidence of excessive tapering in a study comparing the total occlusal convergence values of crown preparations with those of the ideal preparation for 3 different teeth in 4 different planes. The total occlusal convergence for the molar preparations had the highest mean values.

A systematic review of screw- versus cement-retained implant-supported fixed restorations.

PURPOSE: To systematically evaluate the survival and success of screw- versus cement-retained implant crowns. MATERIALS AND METHODS: The authors performed an electronic search of nine databases using identical MeSH phrases. Systematic evaluation and data extraction of the articles from 1966 through 2007 were completed by three reviewers and two clinical academicians. The major outcome variable was implant or crown loss, and the minor outcome variables were screw loosening, decementation, and porcelain fracture. Random effects Poisson models were used to analyze the failure and complication rates. RESULTS: The initial search produced 26,582 articles. Of these, 577 titles and subsequently 295 abstracts were available for evaluation, with 81 full texts meeting the criteria for review. Data were extracted from 23 level one and two research studies. Fleiss' kappa interevaluator agreement ranged from almost perfect to moderate. Major failures included 0.71 screw-retained and 0.87 cement-retained failures per 100 years. Minor failures included 3.66 screw loosenings, 2.54 decementations, and 0.46 porcelain fractures per 100 years. CONCLUSION: There is no significant difference between cement- and screw-retained restorations for major and minor outcomes with regard to implant survival or crown loss. This is important data, as clinicians use both methods of restoration, and neither is a form of inferior care.

Bond strength of the porcelain repair system to all-ceramic copings and porcelain.

PURPOSE: The purpose of this study was to investigate the shear bond strength of the porcelain repair system on alumina and zirconia core ceramics, comparing this strength with that of veneering porcelain. MATERIALS AND METHODS: Veneering ceramic (n = 12), alumina core (n = 24), and zirconia core (n = 24) blocks measuring 10 × 5 × 5 mm(3) were fabricated. Veneering ceramic blocks were used as the control. Alumina and zirconia core blocks were divided into 2 groups (n = 12 each), and a slot (2 × 2 × 4 mm(3)) filled with veneering ceramics was prepared into one of the alumina and zirconia core groups (n = 12). Followed by surface treatments of micro-abrasion with 30 µm alumina particles, etching with 35% phosphoric acid and silane primer and bond, composite resin blocks (2 × 2 × 2 mm(3)) were built up and light polymerized onto the treated surfaces by 3 configurations: (a) composite blocks bonded onto veneering ceramic surface alone, (b) composite blocks bonded onto alumina core or zirconia core surfaces, (c) a 50% surface area of the composite blocks bonded to veneering ceramics and the other 50% surface area of the composite blocks to alumina core or zirconia core surfaces. The shear bond strength of the composite to each specimen was tested by a universal testing machine at a 0.5 mm/min crosshead speed. The shear bond strength was analyzed by unpaired t-tests for within the configuration groups and ANOVA for among the different configuration groups. RESULTS: When the mean shear bond strength was compared within groups of the same configuration, there were no statistically significant differences. Comparison of the shear bond strength among groups of different configurations revealed statistically significant differences. The mean shear bond strength of composite onto 100% veneering ceramic surface and composite onto 50% veneering 50% all-ceramic cores was statistically higher than that of composite onto 100% all-ceramic cores; however, the differences of the shear bond strength of composite bonded only onto the veneering ceramic surface were not statistically significant from those of 50% surface area of composite bonded onto all-ceramic cores. CONCLUSION: No statistically significant differences in the bond strength of a porcelain repair system to alumina and zirconia copings were observed. Increasing the surface of veneering ceramics to a porcelain repair system improved the repair material's bond strength.

Predoctoral dental students' perceptions and experiences with prosthodontics.

PURPOSE: The aims of this study were to: (1) investigate the perceptions and experiences of predoctoral dental students and advanced standing students on mentorship, exposure to prosthodontics, and future need for the specialty, and (2) establish a baseline of students' perceptions of the impact of prosthodontics on salary, personal and patient quality of life, and the profession of dentistry. MATERIALS AND METHODS: A survey was distributed to 494 predoctoral and advanced standing students at the University of Pennsylvania School of Dental Medicine. Questions focused on the perceptions and experiences with the specialty of prosthodontics. A total of 410 surveys were analyzed using Chi Square tests and univariate and multivariate analysis with statistical software. RESULTS: Response rate was 83%. A positive initial introduction to prosthodontics was reported by 57% of students. Most students had positive experiences with prosthodontic faculty and enjoyed laboratory work and challenging/complex dentistry. A greater need for prosthodontists in the future was perceived by 82% of respondents, with 63% reporting that the future of prosthodontics had been emphasized. Students reported (1) a preclinical course directed by prosthodontists and (2) working in the clinic with prosthodontic faculty (p < 0.006) as having the biggest impact on their introduction to prosthodontics. A desire to pursue training or a career in prosthodontics was reported by 3.4% of the respondents, with 1.7% of them pursuing prosthodontics. Enjoyment of providing care in prosthodontics was the most important factor for those who decided to pursue prosthodontic postgraduate training. When compared to other specialties, prosthodontics ranked low with regards to its impact on salary (7(th) ), personal quality of life (5(th) ), patient quality of life (4(th) ), and strengthening of the dental field (7(th) ). CONCLUSION: Reasons few students are interested in prosthodontics as a career, despite a positive first introduction and high perceived future need for prosthodontists may be attributed to a number of factors. These include insufficient prosthodontically, trained faculty, lack of a mentorship program, lack of an advanced graduate program, a perception of feeling unprepared upon graduation, and misconception of potential income in prosthodontics.

Dental students' perceptions of dental specialties and factors influencing specialty and career choices.

The goals of this study were to 1) evaluate dental students' perceptions of dental specialties, 2) identify factors that play an important role in students' decision to pursue specialty training or career choices, and 3) establish a baseline of students' perceptions of the dental fields with the best future in terms of salary, personal and patient quality of life, and overall impact on the dental profession. Surveys were distributed to 494 students at the University of Pennsylvania School of Dental Medicine. Data were collected from 380 traditional four-year students and thirty advanced standing students. Chi-square tests, multivariate analysis, and logistic regressions were used to determine associations and independent contributions of student demographics to their perceptions of dental specialties and factors influencing specialty training or career choices. Debt was a statistically significant factor (p<0.001) in choosing specialty training or career independent of gender, age, or class year. Enjoyment of providing care in a specialty or field was identified as the single most important factor in choosing a specialty career. Half of the respondents had decided not to specialize. Pursuing postdoctoral general dentistry training and private practice in general dentistry were the most commonly reported plans after completion of dental school. Suggestions are made for ways to inform students about specialty training.

A 10-year survey of US deans: trends, challenges, and mentoring in prosthodontics. Part 2.

PURPOSE: Part 2 of this survey reports on the 2009 survey findings distributed to the deans of US dental schools. A national, electronic survey of 58 dental school deans was distributed by e-mail to evaluate an interest in specialty training, an interest in specialty training in prosthodontics, faculty shortage issues, predoctoral curriculum in prosthodontics, ideology regarding dental specialties, and the administrative position of prosthodontics within the schools. MATERIALS AND METHODS: The survey data were transferred to an online spreadsheet program for statistical analysis (Key Survey, Inc. http://www.keysurvey.com, Braintree, MA). The opinions of dental school deans were viewed as legitimate indicators of change within predoctoral and postdoctoral prosthodontic education. Statistical analysis was carried out using Statistica Version 9.1 (Statsoft, Tulsa, OK). RESULTS: Of the 58 deans, 42 deans responded, for a 72.4% response rate. Twenty-three deans reported an increase in the number of students seeking specialty training after dental school. Only three deans reported a decrease in those seeking specialty training. In the 2009 survey, 45% the deans responded that there was an increased interest in prosthodontics. One or more open faculty positions in prosthodontics existed at 24 (59%) of the dental schools, and 30 (71%) offered at least one incentive or a variety of incentives to recruit faculty. The 2009 respondents to the deans' survey revealed predoctoral student exposure to prosthodontists was high, and exposure to advanced education in prosthodontics students was low. A survey of internal school programs that might have an impact on an increased interest in prosthodontics revealed the presence of a predoctoral mentoring program for prosthodontics in 36 (88%) of the institutions. The clinical curriculum included treatment of a variety of cases including complex cases as defined by a diagnostic classification system. The 2009 survey respondents reported an increase in the number of schools where prosthodontics is a separate entity or department. CONCLUSION: Deans reported an increased interest in prosthodontics in the 2009 survey. Open faculty positions in prosthodontics existed in the majority of dental schools, and most schools offered incentives to recruit faculty. The survey of deans found a very high level of exposure of dental students to full-time prosthodontists and a very low exposure level to students enrolled in advanced education in prosthodontics. The establishment of mentoring programs in prosthodontics was reported by most deans, and the predoctoral curriculum included treating complex cases. Most deans stated that dual-specialty training in prosthodontics and periodontics would be beneficial. The 2009 survey reported an increase in the number of departments of prosthodontics in US schools.

Increasing predoctoral dental students' motivations to specialize in prosthodontics.

This study provides data about factors that influence dental students' decision of which specialty to pursue and describes program changes in prosthodontics designed to expand student interest in a prosthodontics training program. Of 176 current and recently graduated students at Harvard School of Dental Medicine, 167 responded to the e-mail survey for a 94.9 percent response rate. Using the Pearson chi-square analysis, we analyzed nine factors to determine their contribution to these students' choice of specialty. Two factors, lecture and faculty/mentoring, were highly significant (p<0.006) regarding impact on the students' introductory experience with prosthodontics. When choosing a specialty, 44 percent of all students ranked "enjoyment of providing the specialty service" as the most important factor. Students wishing to specialize in prosthodontics, however, ranked four significant factors: enjoyment of providing the specialty service (p<0.037, p<0.057); faculty influence (p<0.0002, p<0.0001); length of program (p<0.039, p<0.006); and cost of program (p<0.023, p<0.004). Respondents also ranked the nine American Dental Association-recognized specialties regarding their perceptions of future salary and impact on the dental profession. They ranked prosthodontics fourth for future salary and fifth for impact on the profession. At the same time that this study was being conducted, key changes were being made in the graduate prosthodontics program; those appear to have had a positive impact on students' interest in pursuing prosthodontics as a specialty.

Ten-year survey of program directors: trends, challenges, and mentoring in prosthodontics. Part 1.

PURPOSE: This study consisted of two parts. Part 1 was a survey of US program directors, and Part 2 reports on the survey findings distributed to the deans of US dental schools. Both surveys evaluated observations of trends in prosthodontic education. The first survey (2005) of program directors and deans was published in 2007. This second survey was conducted in 2009. The 2009 survey provided 10-year data on trends in prosthodontics as reported by program directors. MATERIALS AND METHODS: A national e-mail survey of 46 program directors was used to collect enrollment data for years 1 to 3 of prosthodontics training for US and international dental school graduates, the total number of applicants and applications considered, and the trends over time of applicants to prosthodontics for US dental school graduates and for international graduates. In addition, the program directors were asked to rank 13 key factors that may have contributed to any changes in the prosthodontic applicant pool. Program directors were also asked for information on student financial incentives and whether their programs were state or federally funded, and whether their sponsoring institution was a dental school. RESULTS: Of the 46 program directors, 40 responded, for an 87% response rate. Respondents reported that 66% of their enrollees were graduates of US dental schools. Between 2000 and 2009 the applicant pool in prosthodontics nearly doubled, with 50% of the program directors reporting an increase in US-trained applicants, 42.5% reporting no change, and only 7.5% reporting a decrease. Using the Spearman correlation for the 10-year survey, there was a positive, statistically significant correlation that society's demand for a higher level of training and credentialing and interest in prosthodontics among dental students contributed to an increase in the number of US dental graduates applying to prosthodontic programs. Only four programs offered no financial packages to offset tuition. The remaining 36 respondents reported some financial package. Among the respondents, there were 23 state-sponsored programs and 6 sponsored by private universities; the remaining 9 were sponsored by hospitals or federal agencies. CONCLUSIONS: A nearly doubled applicant pool and more US-trained applicants to prosthodontics ensure a much more competitive applicant pool for our specialty. In the 2009 survey, program directors reported that factors such as society's demand for a higher level of training and credentialing, interest in prosthodontics among US dental students, advances in implant, esthetic, and reconstructive dentistry, literature pertaining to the need of prosthodontists for the future, marketing of prosthodontics as a career, and the dollar value of prosthodontic training have all had some impact on increasing the mentored applicant pool to prosthodontic training in the United States.

Clinician- and patient-reported long-term evaluation of screw- and cement-retained implant restorations: a 5-year prospective study.

The purpose of this study was to evaluate the survival and success of screw- versus cement-retained implant crowns over a 5-year period. This was a multi-center prospective cohort study, consisting of patients who had ≥1 dental implant placed and restored in the anterior maxilla over a 5-year period. The primary predictor variable was the type of restoration (screw- versus cement-retained). The outcome variables were clinician- or patient-reported measures related to soft tissue and restoration quality. Descriptive and bivariate statistics were computed to compare the screw- versus cement-retained groups. Kaplan-Meier statistics were computed for implant survival. Information was collected for 102 patients who had 214 implants placed during the study period. Complete data, amenable to analysis, were available for 99 (97.1%) patients and 193 (90.2%) implants. The restorations were approximately evenly divided between screw- (53.4%) and cement-retained (46.6%). Approximately 49% of patients in the sample were female; the sample's mean age was 47.3 ± 13.9 years; each patient had an average of 2.0 ± 1.0 implants placed and restored. The mean time from prosthesis placement (definitive) to study endpoint was 61.9 ± 10.6 months. The overall implant survival rate was 96.4%, with no statistically significant difference in survival between the screw- and cement-retained groups (p = 0.45). The majority of clinician- and patient-assessed outcomes were similar. The results of this study indicate that for the majority of clinician- and patient-assessed success parameters screw- and cement-retained restorations are equivalent in the anterior maxilla.

In vitro study of the correlation between the simulated clinical and radiographic examination of microgaps at the implant-abutment interface.

OBJECTIVES: To analyze the diagnostic value of the clinical and radiographic investigation of the interface of two-piece implant systems under the variables crevice size of the microgap, clinical experience, radiograph exposure time, prosthesis design, and type of evaluation. METHOD AND MATERIALS: A simulated mandibular cast with five screw-retained implants (Straumann) providing three different prosthesis designs displayed artificially created proximal, visually inaccessible microgaps of unequal sizes or junctions without any measurable gap formation. Three groups of 15 investigators each with a different degree of clinical experience evaluated the implant-abutment interfaces of the cast clinically and radiographically. The investigation was conducted on the basis of a scoring form adapted from the receiver operating characteristic (ROC) 5-choice method. Radiographs were prepared in two exposure times (0.1 second, 0.2 second) for each junction. Radiographs of the initial situation without any measurable gap formation were shown as a control and to detect false-positive scores for each gap size. A 10-point SEM measurement of the junctions served for standardization purposes. Statistical methods included ROC analysis, kappa analysis, and a regression analysis (alpha = .05). RESULTS: Gaps greater than 150.9 microm (P < .001) were detected 227% more frequently and gaps greater than 189.7 microm 292% more frequently via radiographic examination. Kappa values were adequate for the radiographic examination and unsatisfactory for clinical examination. Prosthetic superstructure and exposure time did not adversely affect the diagnosis. Clinical experience improved the detection of microgaps significantly. CONCLUSION: A relationship between the size of microgaps and the examiners' ability to detect them can be established. Whereas tactile examination alone is not accurate enough, radiographic analysis affiliated with a certain degree of clinical experience possesses features for an adequate clinical management of restoration defects.

The effect of surface treatment of fiber-reinforced posts on adhesion of a resin-based luting agent.

STATEMENT OF PROBLEM: Surface treatment of fiber-reinforced posts may not always increase adhesion, especially on the post/resin-based luting agent interface, which is a weaker interface than the dentin/adhesive interface. PURPOSE: The purpose of this in vitro study was to evaluate the influence of different post surface treatments on the bond strength of a luting agent to a fiber post. MATERIAL AND METHODS: Sixty-eight fiber-reinforced posts (D. T. Light-Post) were divided into 4 groups and treated with 1 of the following surface treatment procedures: no treatment (NS) (control), silanization (SA) (Monobond-S), airborne-particle abrasion (AB) (Airsonic Alu-Oxyd), or silanization subsequent to airborne-particle abrasion (AB plus SA). Specimens were bonded with dual-polymerizing resin-based luting material (Variolink II) and stored in water at 37 degrees C for 24 hours. Shear bond strength (MPa) was measured using a universal testing machine. Data were analyzed with 1-way ANOVA and the multiple comparisons Scheffé test with Bonferroni correction (alpha=.05). RESULTS: Shear bond strength of the luting agent to the post was significantly affected by surface treatment (P<.05). Treating the surface of the post with airborne-particle abrasion resulted in a significantly higher bond strength compared with other treatments. There was no significant difference in bond strength between the silanization group and the no treatment group or the silanization plus airborne-particle abrasion group. CONCLUSIONS: Airborne-particle abrasion provided a significant increase in bond strength between the post and the luting agent evaluated, without additional treatments.

The effect of impression volume and double-arch trays on the registration of maximum intercuspation.

STATEMENT OF PROBLEM: The type of double-arch trays used may affect occlusion. PURPOSE: The purpose of this study was to determine what effect, if any, double-arch tray design and impression material volume had on the registration of maximum intercuspation (MI). MATERIAL AND METHODS: Quadrant impressions were made on articulated fracture-resistant dental casts mounted in maximum intercuspation occlusion. Three types of sideless double-arch impression trays were used: First Bite with nylon webbing, Sultan's 3-Way with double crosshatch webbing, and Premium's 3-in-1 Tray with single crosshatch webbing. Vinyl polysiloxane impression material (Aquasil Ultra Rigid Fast Set) was distributed at 2 different volumes (5.4 ml and 8.3 ml), and 60 impressions were made (n=10). A weight of 1.2 kg was placed on the upper arm of an Artex articulator, ensuring complete closure. The impressions were allowed to polymerize for 5 minutes. After polymerization, specimens were placed on a light box, and a camera set at a fixed distance was used to capture the light transmission that was projected through the impression material. The camera transferred the information to an image analysis program (ImageJ). This system allowed the different amounts of light projected through the impression to be translated into a gray scale value (GSV), which was assigned a thickness value, in millimeters, of a specified occlusal contact area. To assess reliability of the experimental design, 10 control impressions were made by directly applying impression material onto the typodont. These were analyzed in the same manner as the impressions made with trays. A 2-way ANOVA comparing volume by tray type was used (alpha=.05). This was followed by a Tukey HSD test. RESULTS: There was no main effect for volume of impression material (P=.71). Tray type was significantly different (P<.001). Impressions made with Sultan trays were significantly less accurate than impressions made with First Bite or Premium impression trays. The Premium tray type had the highest mean (SD) GSV, 179.8 (8.1), significantly higher than First Bite (164.7 (19.8); P<.001) or Sultan (82.8 (7.4); P<.001) trays. CONCLUSIONS: This in vitro study demonstrated that certain trays hinder closure into MI, which may negatively affect the accuracy of record making.

Fixed mandibular and maxillary implant rehabilitation in a fully edentulous patient: a case report.

The complete dental rehabilitation of a patient with a failing dentition using fixed implant-supported prostheses requires carefully planned and well-sequenced treatment. This case report presents the treatment steps and sequencing for a patient in whom removable provisional prostheses were not an option. While an immediate loading protocol was used in the mandible, a staged approach featuring strategic extractions and implant placement in several phases was applied in the maxilla. The major advantage of this treatment protocol was that the patient was maintained in fixed prostheses throughout the treatment.

A systematic review of the clinical performance of CAD/CAM single-tooth restorations.

PURPOSE: This systematic review sought to determine the long-term clinical survival rates of single-tooth restorations fabricated with computer-aided design/computer-assisted manufacture (CAD/CAM) technology, as well as the frequency of failures depending on the CAD/CAM system, the type of restoration, the selected material, and the luting agent. MATERIALS AND METHODS: An electronic search from 1985 to 2007 was performed using two databases: Medline/PubMed and Embase. Selected keywords and well-defined inclusion and exclusion criteria guided the search. All articles were first reviewed by title, then by abstract, and subsequently by a full text reading. Data were assessed and extracted by two independent examiners. The pooled results were statistically analyzed and the overall failure rate was calculated by assuming a Poisson-distributed number of events. In addition, reported failures were analyzed by CAD/CAM system, type of restoration, restorative material, and luting agent. RESULTS: From a total of 1,957 single-tooth restorations with a mean exposure time of 7.9 years and 170 failures, the failure rate was 1.75% per year, estimated per 100 restoration years (95% CI: 1.22% to 2.52%). The estimated total survival rate after 5 years of 91.6% (95% CI: 88.2% to 94.1%) was based on random-effects Poisson regression analysis. CONCLUSIONS: Long-term survival rates for CAD/CAM single-tooth Cerec 1, Cerec 2, and Celay restorations appear to be similar to conventional ones. No clinical studies or randomized clinical trials reporting on other CAD/CAM systems currently used in clinical practice and with follow-up reports of 3 or more years were found at the time of the search.