An up to thirty-year retrospective study on the success and survival of single unit and splinted implant-supported crowns in a dental school setting.

STATEMENT OF PROBLEM: Studies investigating the survival of implant-supported crowns provided in a dental school setting are sparse. PURPOSE: The purpose of this retrospective study was to evaluate the success and reasons for failure of single unit and splinted implant-supported crowns provided in a dental school. MATERIAL AND METHODS: Using the axiUm dental management software program and paper charts, all single unit and splinted implant-supported crowns provided between September 1989 and January 2020 were included for evaluation. Success, survival, and failure were recorded as well as reasons for failure. A Kaplan-Meier survival estimate with an associated P value, a life table analysis, and a log-rank test comparing the survival of single unit and splinted implant-supported crowns were performed. RESULTS: Over 30 years, 678 implant-supported crowns (586 single unit and 92 splinted) had been provided. Of these crowns, 17 (2.90%) single unit crowns and 5 (5.43%) splinted crowns failed, with most being prosthetic failures for both single units (64.7%) and splinted (80%), rather than biologic failures. A total of 371 single unit (63.3%) and 46 splinted (50.0%) implant crowns were a complete success, and 215 single unit (36.7%) and 46 splinted (50.0%) crowns survived but had some type of complication. The overall implant-supported crown survival rate was 96.8%. The survival distribution of the single unit and splinted implant-supported crowns was not statistically significantly different [χ2(2)=1.285, P=.257]. CONCLUSIONS: Both single unit and splinted implant-supported crowns had high success rates and showed similar survival rates. The most common causes of complications were also similar, with debonding and screw loosening of crowns being the most common complication for both single unit and splinted crowns.

Effect of Different Post-Curing Methods on the Degree of Conversion of 3D-Printed Resin for Models in Dentistry.

The aim was to investigate the effects of different post-curing units on the chemical properties (degree of conversion) of 3D-printed resins for producing models in dentistry. The goal is to determine whether less-expensive post-curing units can be a viable alternative to the manufacturer's recommended units. Forty-five samples were fabricated with an LCD printer (Phrozen Sonic Mini, Phrozen 3D, Hsinchu City, Taiwan) using MSLA Dental Modeling Resin (Apply Lab Work, Torrance, CA, USA). These samples were divided randomly into four different groups for post-curing using four distinct curing units: Phrozen Cure V2 (Phrozen 3D, Hsinchu City, Taiwan), a commercial acrylic nail UV LED curing unit (SUNUV, Shenzhen, China), a homemade curing unit created from a readily available UV LED light produced (Shenzhen, China), and the Triad® 2000™ tungsten halogen light source (Dentsply Sirona, York, PA, USA). The degree of conversion was measured with FTIR spectroscopy using a Nicolet 6700 FTIR Spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Phrozen Cure V2 had the highest overall mean degree of conversion (69.6% with a 45 min curing time). The Triad® 2000 VLC Curing Unit had the lowest mean degree of conversion value at the 15 min interval (66.2%) and the lowest mean degree of conversion at the 45 min interval with the homemade curing unit (68.2%). The type of light-curing unit did not yield statistically significant differences in the degree of conversion values. There was a statistically significant difference in the degree of conversion values between the 15 min and 45 min curing intervals. When comparing individual light-curing units, there was a statistically significant difference in the degree of conversion for the post-curing units between the 15 min and 45 min curing time (p = 0.029).

An In Vivo Investigation of Non-Metallic vs. Metallic Hand Scalers on Zirconia Implant-Supported Crowns: A Year-Long Analysis of Peri-Implant Maintenance.

This study examined whether the degree of abutment surface modification that may occur with regular periodontal instrumentation has a clinical impact in terms of increased plaque accumulation and increased peri-implant tissue inflammation on zirconia implant abutments. Thirteen patients who had zirconia implant crowns were recruited in this randomized clinical trial. Each patient acted as their control and had either the buccal or lingual surface of their screw-retained implant restoration scaled with a metallic scaler and the other surface with a non-metallic scaler at 3, 6, 9, and 12 months. Cytokine testing of the peri-implant crevicular fluid was completed at 0, 3, and 12 months for IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, or IFNγ. Implant crowns were removed at 12 months and evaluated under an atomic force microscope for the average roughness (Ra). The implant crowns were polished and re-inserted. The results were analyzed using the Kruskal-Wallis test, and post hoc tests were conducted with a significance level of α = 0.05. Significant differences in surface roughness (Ra) were observed between the metallic and non-metallic scalers. The median Ra values were 274.0 nm for metallic scalers and 147.1 nm for non-metallic scalers. However, there were no significant differences between the type of scaler used and the amount of clinical inflammation or cytokine production. Metallic scalers produced deeper, more aggressive surface alterations to the abutment/crown zirconia surface, but there was no statistically significant difference between the degree of surface alterations, amount of BOP, and the amplitude of cytokine inflammation produced.

Twelve-year survival of 2-surface composite resin and amalgam premolar restorations placed by dental students.

STATEMENT OF PROBLEM: Composite resin and amalgam restorations are indicated for the restoration of posterior teeth. With increased esthetic demands, long-term clinical studies are required to evaluate the restorative success and reasons for failure of these materials. PURPOSE: The purpose of this retrospective study was to determine the survival and reasons for failure of directly placed 2-surface composite resin restorations and directly placed 2-surface amalgam restorations on premolars placed by Canadian dental students. MATERIAL AND METHODS: Using The University of Manitoba's dental management software and paper charts, all 2-surface composite resin and 2-surface amalgam restorations placed on premolars between January 1, 2002, and May 30, 2014, were included. Short-term failure (within 2 years), long-term failure, and reasons for failure were collected. A Kaplan-Meier survival estimate with an associated P value comparing composite resin to amalgam restoration curves was performed using SPSS statistical software. RESULTS: Over 12 years, 1695 composite resin and 1125 amalgam 2-surface premolar restorations were placed. Of these restorations, 134 composite resins (7.9%) and 66 amalgams (5.9%) failed. Short-term failures (2 years or less) consisted of 57 composite resin (4%) and 23 amalgam (2.3%) restorations. Long-term failures (greater than 2 years) consisted of 77 composite resin (4.5%) and 43 amalgam (3.8%) restorations. After 12 years of service, the survival probability of composite resin restorations was 86% and that of amalgam restorations 91.5%. The differences in composite resin and amalgam survival curves were also found to be statistically significant (P=.009 for Log-rank test). The main reasons for failure were recurrent caries and fracture of the tooth being restored. CONCLUSIONS: Within the limitations of this study, both composite resin and amalgam restorations had acceptable success rates and similar failure modes. Recurrent caries was still the most common reason for failure.

Degree of Conversion and Oxygen-Inhibited Layer Effect of Three Dental Adhesives.

This study investigated the effect of the oxygen-inhibited layer on the degree of conversion (DC) of three dental adhesives, comparing two different protocols. Quartz-tungsten-halogen (QTH) light curing and light-emitting diode (LED) were used to cure three adhesives: OptiBond All in One (OAIO), Adper Easy Bond (AEB) and ExciteF (EXF). The DC was calculated utilizing Fourier Transform infrared spectroscopy (FTIR) (n = 12). The two protocols used were as follows: (i) prevent the oxygen-inhibited layer using a Mylar plastic strip pushed onto each bonding adhesive; and (ii) polymerize samples without a plastic strip. The data was analyzed statistically by a three-way ANOVA, and Tukey Test (a = 0.05). The presence of an oxygen-inhibited layer reduced the DC of the adhesives by 64% for EXF, 46% for AEB and 32% for OAIO. This study suggests that there are differences among the oxygen-inhibited layers present for the adhesives tested.

Use of an obturator with nCPAP in a premature infant with a cleft lip and palate.

Premature infants have underdeveloped lungs and their care involves the use of nasal continuous positive airway pressure (nCPAP). For an adequate amount of oxygen to enter the lungs, the palate needs to be intact. Premature infants with a cleft lip and palate remain intubated for extended periods of time with the risks inherent in long-term intubation because of the inability to maintain nCPAP. This paper describes the fabrication of a custom-designed obturator attached to nCPAP variable flow generator tubing for a premature infant with a unilateral cleft lip and palate.

Longitudinal comparison of cytokines in peri-implant fluid and gingival crevicular fluid in healthy mouths.

BACKGROUND: Peri-implant and gingival tissues provide important sealing and protective functions around implants and teeth, but comparisons of the immunologic responses of these tissues after implant placement have not been conducted. Cytokine levels were measured in peri-implant crevicular fluid (PICF) and gingival crevicular fluid (GCF) as surrogate measures of immune function at subcrestally placed dental implants and healthy periodontal sites during a 1-year monitoring period. METHODS: A total of 27 dental implants were placed subcrestally in 21 periodontally healthy patients (mean age: 49.0 ± 13.4 years). Repeated clinical and cytokine measurements were obtained over 12 months. GCF and PICF samples were collected and analyzed by cytokine microarray. Data were examined by non-parametric analysis of variance. RESULTS: Plaque and bleeding indices were similar among all patients (P >0.05) at baseline. During 1 year of monitoring, the mean volumes of PICF and GCF were similar (P >0.05). The levels of interleukin (IL)-4, -6, -10, and -12p70, tumor necrosis factor-α, and interferon-γ in GCF and PICF were not significantly different and did not vary over time (P >0.05). The levels of IL-1α were higher in GCF than PICF at 1, 2, 6, and 12 months, as were the levels of IL-8 at 1, 2, 4, 6, and 12 months (P <0.001). Transforming growth factor-ß1 in PICF and GCF exhibited time-dependent increases, and vascular endothelial growth factor was reduced at 1 year without differences between PICF and GCF (P >0.05). CONCLUSION: Within the limitations of this study design, it can be concluded that after subcrestal implant placement, the immune response of peri-implant and periodontal tissues, as assessed by cytokine levels in PICF and GCF, is similar.

The effect of metal ceramic restoration framework design on tooth color.

STATEMENT OF PROBLEM: The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. PURPOSE: The purpose of this study was to investigate the color change that occurs apically to a metal ceramic restoration as a result of altering the metal framework design. MATERIAL AND METHODS: Color change relative to the unprepared tooth (DeltaE) between various metal ceramic restorations was determined using computer imaging and CIELAB coordinates and compared to previously determined levels of clinical acceptability. Color change was evaluated by examining 2 conditions (the metal copings and the completed metal ceramic restorations), 4 framework designs (metal collar and porcelain margins with 0-mm, 1-mm, or 2-mm cutbacks), and 2 locations on the tooth apical to the margin of the restoration, using an imaging system developed at the Minnesota Dental Research Center for Biomaterials and Biomechanics. The data were analyzed statistically using repeated measures analysis of variance (P=.05). RESULTS: For metal ceramic restorations there exists a significant (P=.001) color change (DeltaE) between all framework designs except for the 0-mm and 1-mm cutbacks. Color change (DeltaE) in the location above the cemento-enamel junction was significantly greater (P=.004) than below the cemento-enamel junction. CONCLUSIONS: The framework design for metal ceramic restorations can affect the esthetics of the adjacent natural tooth. A minimum 2-mm facial cutback of the metal framework is necessary for there to be a significant difference in color change.

Three-way trays: easy to use and abuse.

The 3-way tray technique is popular as it provides master and opposing arch impressions and an interocclusal record at the same time. Excellent clinical results can be achieved with appropriate case selection, use of rigid tray and impression materials, attention to tray positioning and other details throughout the process, and clear understanding of the limitations of the technique by the operator and dental technician.

Current ceramic materials and systems with clinical recommendations: a systematic review.

STATEMENT OF PROBLEM: Developments in ceramic core materials such as lithium disilicate, aluminum oxide, and zirconium oxide have allowed more widespread application of all-ceramic restorations over the past 10 years. With a plethora of ceramic materials and systems currently available for use, an overview of the scientific literature on the efficacy of this treatment therapy is indicated. PURPOSE: This article reviews the current literature covering all-ceramic materials and systems, with respect to survival, material properties, marginal and internal fit, cementation and bonding, and color and esthetics, and provides clinical recommendations for their use. MATERIAL AND METHODS: A comprehensive review of the literature was completed seeking evidence for the treatment of teeth with all-ceramic restorations. A search of English language peer-reviewed literature was undertaken using MEDLINE and PubMed with a focus on evidence-based research articles published between 1996 and 2006. A hand search of relevant dental journals was also completed. Randomized controlled trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies, and longitudinal retrospective studies were reviewed. The last search was conducted on June 12, 2007. Data supporting the clinical application of all-ceramic materials and systems was sought. RESULTS: The literature demonstrates that multiple all-ceramic materials and systems are currently available for clinical use, and there is not a single universal material or system for all clinical situations. The successful application is dependent upon the clinician to match the materials, manufacturing techniques, and cementation or bonding procedures, with the individual clinical situation. CONCLUSIONS: Within the scope of this systematic review, there is no evidence to support the universal application of a single ceramic material and system for all clinical situations. Additional longitudinal clinical studies are required to advance the development of ceramic materials and systems.

Shaping abilities of two different engine-driven rotary nickel titanium systems or stainless steel balanced-force technique in mandibular molars.

The purpose of this study was to compare apical transportation, working-length changes, and instrumentation time by using nickel-titanium (Ni-Ti) rotary file systems (crown-down method) or stainless steel hand files (balanced-force technique) in mesiobuccal canals of extracted mandibular molars. The curvature of each canal was determined and teeth placed into three equivalent groups. Group 1 was instrumented with Sequence (Brasseler USA, Savannah, GA) rotary files, group 2 with Liberator (Miltex Inc, York, PA) rotary files, and group 3 with Flex-R (Union Broach, New York, NY) files. Pre- and postoperative radiographs were superimposed to measure loss of working length and apical transportation as shown by changes in radius of curvature and the long-axis canal angle. Sequence rotary files, Liberator rotary files, and Flex-R hand files had similar effects on apical canal transportation and changes in working length, with no significant differences detected among the 3 groups. Hand instrumentation times were longer than with either Ni-Ti rotary group, whereas the rotary NiTi groups had a higher incidence of fracture.

Retrospective cross sectional comparison of initial nonsurgical endodontic treatment and single-tooth implants.

Initial root canal treatment and the replacement of a single tooth with an implant are both viable treatment options, but various success rates have been reported for each treatment modality. This retrospective study compared 196 implant restorations and 196 matched initial nonsurgical root canal treatment (NSRCT) teeth in patients for four possible outcomes: success, survival, survival with subsequent treatment intervention and failure. Cross classifications/tabulations were analyzed using Pearson's chi2 test for association of the two classifications (endodontic vs implant and outcome). Polytomous regression with likelihood ratio tests were used in testing association with tooth location and outcome. Outcomes were as follows for implants and NSRCT respectively: success 73.5% and 82.1%; survival with no intervention 2.6% and 8.2%; survival with intervention 17.9% and 3.6%; and failure 6.1% and 6.1%. Location of the restoration in the mouth did not affect outcome. This study suggests that restored endodontically treated teeth and single tooth implant restorations have similar failure rates, although the implant group showed a longer average and median time to function and a higher incidence of postoperative complications requiring subsequent treatment intervention.

Accuracy of two impression techniques with angulated implants.

STATEMENT OF PROBLEM: Accurate recording of implant locations is required so that definitive restorations are properly supported and do not place additional stress on the implants. Angulated implants may result in inaccurate impressions, and the impression technique may affect the accuracy of the definitive cast. PURPOSE: The purpose of this study was to determine the effect the combined interaction of impression technique, implant angulation, and implant number has on the accuracy of implant definitive casts. MATERIAL AND METHODS: One definitive stone cast was fabricated for each of 6 experimental groups and 1 control group. All 7 definitive casts had 3 implants arranged in a triangular pattern creating a plane. In the 6 experimental groups, the center implant was perpendicular to the plane of the cast while the outer implants had 5, 10, or 15 degrees convergence towards or divergence away from the center implant. The control definitive cast had all 3 implants parallel to each another and perpendicular to the plane of the cast. Five open tray and 5 closed tray addition silicone impressions were made of each definitive cast. Impressions were poured with type IV dental stone, and a fine tip measuring stylus was used to record multiple axis (X-Y-Z) coordinates on the top surface of the implant hex and on the cast base. Computer software was used to align the data sets and vector calculations determined the difference in degrees between the implant angles in the definitive cast and the duplicate casts. Statistical analysis used repeated-measures ANOVA (alpha=.05) with post-hoc tests of significant interactions. RESULTS: The angle errors for the closed and open tray impression techniques did not differ significantly (P=.22). Implant angulations and implant numbers differed in average angle errors but not in any easily interpreted pattern (P<.001). The combined interaction of impression technique, implant angulation, and implant number had no effect on the accuracy of the duplicate casts compared to the definitive casts (P=.19). CONCLUSIONS: The average angle errors for the closed and open tray impression techniques did not differ significantly. There was no interpretable pattern of average angle errors in terms of implant angulation and implant number. The magnitude of distortion was similar for all combinations of impression technique, implant angulation, and implant number.

Factors affecting outcomes for single-tooth implants and endodontic restorations.

Initial root canal therapy and implant placement are both common treatment modalities, and, as such, prognostic factors that influence the treatment outcomes of these two restorations should be identified. In a retrospective chart review, 196 implant restorations and 196 matched initial nonsurgical root canal treated (NSRCT) teeth in patients were evaluated for four possible outcomes-success, survival, survival with intervention, and failure. Results showed that smokers had fewer successes and more failures in both groups (p = 0.0001), whereas NSRCT outcomes were affected by periradicular periodontitis (p = 0.001), post placement (p = 0.013), and overfilling (p = 0.003). Outcomes for both groups were not significantly affected by diabetes, age, or gender. Implant group outcomes were not affected by implant length (from 10 to 16 mm), diameter (from 3.25 to 5.5 mm), or an adjacent endodontically treated tooth, nor were NSRCT outcomes affected by the number of appointments for the procedure.

Retrospective cross sectional comparison of initial nonsurgical endodontic treatment and single-tooth implants.

Initial root canal treatment and the replacement of a single tooth with implants are both viable treatment options, but various success rates have been reported for each treatment modality. This study compared 196 implant restorations and 196 matched initial nonsurgical root canal treatment (NSRCT) teeth in patients for four possible outcomes- success, survival, survival with subsequent treatment intervention and failure. Cross classifications/tabulations were analyzed using Pearson's chi(2) test for association of the two classifications (endo vs. implant and outcome). Polytomous regression with likelihood ratio tests were used in testing association with tooth location and outcome. Outcomes were as follows for implants and NSRCT outcomes, respectively: success 73.5% and 82.1%; survival with no intervention 2.6% and 8.2%; survival with intervention 17.9% and 3.6%; and failure 6.1% and 6.1%. Location of the restoration in the mouth did not affect outcome. This study suggests that restored endodontically treated teeth and single-tooth implant restorations have similar failure rates, although the implant group showed a longer average and median time to function and a higher incidence of postoperative complications requiring subsequent treatment intervention.

A preliminary survey of interprofessional education.

The purpose of this article is to review the literature on interprofessional education (IPE) and report on a preliminary survey of the current status of interprofessional education in seven academic health centers (AHCs) that have schools of dentistry associated with them. There is wide variability in interpretation of the term "interprofessional," and many barriers to interprofessional education exist including already overcrowded curricula in health professions schools, lack of support from faculty and administration, and financial constraints. Based on interviews completed at the authors' home institutions, it was recommended that topics such as ethics, communication skills, evidence-based practice, and informatics could be effectively taught in an interprofessional manner. Currently, some academic health centers are attempting to develop interprofessional education programs, but most of these efforts do not include dental students. Of the seven AHCs investigated in this study, only two had formal interprofessional educational activities that involved students from two or more health professions education programs. Dental school participants in this study professed a strong interest in interprofessional programs, but many interviewees from other professional schools and AHC administrators perceived that the dental school was isolated from other schools and disinterested in IPE. Many health care setting models in the future will include dentists as part of an interdisciplinary health care team; consequently, it is important for dental schools to become an active participant in future interprofessional educational initiatives.

Compliance of resilient denture liners immersed in effervescent denture cleansers.

PURPOSE: Six resilient denture liners (RDL) were exposed to two immersion effervescent denture cleansers to evaluate change in compliance over a simulated 1 year time interval. MATERIALS AND METHODS: Ten samples of each material, Molloplast B, Mollosil, MPDS-SL, Permasoft, Softline, and Sofreliner were exposed to either Fixodent or Efferdent denture cleanser. A cyclic load was applied in a squarewave fashion to derive a load displacement curve to measure compliance at 0, 7, 30, 180, and 360 simulated days. RESULTS: All 12 of the material/cleanser combinations demonstrated a significant change in compliance at each time interval relative to baseline. Mollosil had the greatest increase in flexibility from baseline, and MPDS-SL had the smallest increase in flexibility. In general, chairside materials demonstrated greater change in compliance from baseline compared to laboratory materials. Materials subjected to Fixodent cleanser, when averaged over time, were significantly more flexible than materials exposed to Efferdent cleanser. CONCLUSIONS: Exposure of resilient soft liners to two common cleansers resulted in a significant increase in flexibility. This change in flexibility depended slightly, though significantly, on the type of cleanser, and appeared to be more significant with time. In general, chairside materials seemed to change more than laboratory-processed liners. The exception was Permasoft that was fabricated as a laboratory material but behaved like a chairside material. CLINICAL SIGNIFICANCE: The initiator of the polymerization reaction rather than the mode of polymerization may be more important in predicting a change in the flexibility of RDLs. Constituents within the oral environment may be more responsible for changes in RDL flexibility than denture cleansers.

Clinical evaluation of a new resilient denture liner. Part 1: Compliance and color evaluation.

PURPOSE: A new experimental resilient denture liner (MPDS-SL; Lai Laboratories, Burnsville, MN) and Molloplast-B (Buffalo Dental Manufacturing, Syosset, NY) were clinically evaluated for compliance and color change over a 1-year period. MATERIALS AND METHODS: In this crossover study, each of 20 patients had 2 dentures fabricated with long-term, silicone-based resilient liners, 1 denture with Molloplast-B and the other with MPDS-SL. Each denture was used for 6 months, during which time each patient kept a journal detailing his or her use and cleaning regimen. The 2 materials were assessed for compliance and color at the beginning of the study and again after 3 months and 6 months of use. Compliance was determined by applying a 3-lb force to the surface of the material following a square-wave pattern, using a closed-loop servohydraulic testing system. The force and position values were recorded using a storage oscilloscope. Compliance was measured at 3 locations on each denture and analyzed using data-acquisition software. Images of the dentures were captured using a zoom stereomicroscope with a charge-coupled video camera and image analysis software. The color was measured at 3 locations on each denture; RGB and L* a* b* were calculated. RESULTS: Compliance increased from baseline to 3 months and from 3 months to 6 months for almost all locations on both materials. Molloplast-B and MPDS-SL differed in average change in compliance at 6 months; the average change in compliance from baseline to 6 months was 453 (standard error, 46) for Molloplast-B and 284 (standard error, 46) for MPDS-SL (p = 0.019). For both materials, color changed significantly from baseline to 3 months and from baseline to 6 months (p < 0.01). MPDS-SL changed significantly less than Molloplast-B from baseline to 6 months for R (p = 0.039), G (p = 0.037), B (p = 0.005), and L* (p = 0.042). CONCLUSION: For both materials, compliance increased over 6 months of wear. The color change for MPDS-SL was considerably less significant than that for Molloplast-B.

Patient perceptions of professionalism in dentistry.

The purpose of this study was to examine how patients perceived the professionalism of University of Minnesota School of Dentistry students, faculty, and staff. Professionalism is defined by the authors as an image that will promote a successful relationship with the patient. Patients within comprehensive care clinics were asked to assess physical attributes and behaviors of the dental care providers using a questionnaire. The patients read statements dealing with characteristics of the dental care providers and responded as to whether they agreed, were neutral, or disagreed with the statement. The surveyed population consisted of 103 males and 97 females, 64 percent of whom lacked insurance coverage. Fifty-one percent of the patients were between the ages of forty-four and sixty-nine, but the overall age distribution was dispersed over a range of eighteen to one hundred. Our research found that all dental care providers displayed a professional appearance as well as behavior. The attire of the dental care provider affected the comfort and anxiety levels of patients, as did first impressions of both students and faculty. Most patients reported that students and faculty displayed effective time management and used appropriate language during the appointment. Finally, hairstyle, makeup, and jewelry appeared to have little effect on patients' opinions of the various dental care providers.

Clinical evaluation of resilient denture liners. Part 2: Candida count and speciation.

PURPOSE: The purpose of this study was to count and to speciate Candida isolated from 2 resilient denture liners, Molloplast-B and MPDS-SL. MATERIALS AND METHODS: A group of 20 patients each had 1 maxillary denture and 2 mandibular dentures fabricated. One mandibular denture was lined with Molloplast-B, and 1 was lined with MPDS-SL. Each denture was used for 3 months. At the end of the 3-month period, the mandibular denture was surrendered, and a 5 x 5-mm circular resilient liner sample was obtained from the tissue surface of the lingual flange. Samples were processed, and Candida was isolated and counted. Speciation of Candida was performed using CHROMagar Candida and API 20C AUX strips. RESULTS: Molloplast-B had, on average, 5 times as many CFU/sample as MPDSL-SL, but this difference was not significant (p = 0.26). A sign test gave a similar nonsignificant trend (p = 0.057). CHROMagar identified several Candida species, and confirmation was made using API 20C AUX strips. One patient was lost to follow-up. Of 19 Molloplast-B samples, 7 had no growth, 4 grew C. albicans, 3 grew C. parapsilosis, 2 grew C. glabrata, 1 grew C. tropicalis, 2 grew a Trichosporon spp., and 2 grew a nonidentifiable colony. The analogous counts for 19 MPDS-SL samples were 10, 4, 1, 3, 0, 1, and 1 (p = 0.45 for culture positively, exact McNemar test). CONCLUSIONS: Candida growth on Molloplast-B was not significantly different from growth on MPDS-SL. Several yeast species were cultured from each material. The rates of culture-positive testing did not differ between the 2 resilient denture liners.