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Purpose: This in vitro study evaluated the accuracy of multiple-unit dental implant casts obtained from splinted or nonsplinted direct impression techniques using various splinting materials by comparing the casts to the reference models. The effect of two different impression materials on the accuracy of the implant casts was also evaluated for abutment-level impressions., Materials and Methods: A reference model with six internal-connection implant replicas placed in the completely edentulous mandibular arch and connected to multi-base abutments was fabricated from heat-curing acrylic resin. Forty impressions of the reference model were made, 20 each with polyether (PE) and polyvinylsiloxane (PVS) impression materials using the open tray technique. The PE and PVS groups were further subdivided into four subgroups of five each on the bases of splinting type: no splinting, bite registration PE, bite registration addition silicone, or autopolymerizing acrylic resin. The positional accuracy of the implant replica heads was measured on the poured casts using a coordinate measuring machine to assess linear differences in interimplant distances in all three axes. The collected data (linear and three-dimensional [3D] displacement values) were compared with the measurements calculated on the reference resin model and analyzed with nonparametric tests (Kruskal-Wallis and Mann-Whitney)., Results: No significant differences were found between the various splinting groups for both PE and PVS impression materials in terms of linear and 3D distortions. However, small but significant differences were found between the two impression materials (PVS, 91 μm; PE, 103 μm) in terms of 3D discrepancies, irrespective of the splinting technique employed., Conclusions: Casts obtained from both impression materials exhibited differences from the reference model. The impression material influenced impression inaccuracy more than the splinting material for multiple-unit abutment-level impressions.

A method is described for the fabrication of a closed hollow bulb obturator prosthesis using a hard thermoforming splint material and heat-cured acrylic resin. The technique allowed the thickness of the thermoformed bulb to be optimized for weight reduction, while the autopolymerized seal area was covered in heat-cured acrylic resin, thus eliminating potential leakage and discoloration. This technique permits the obturator prosthesis to be processed to completion from the wax trial denture without additional laboratory investing, flasking, and processing., (© 2013 by the American College of Prosthodontists.)

Dental rehabilitation of a completely edentulous geriatric patient has always been a challenge to the clinician, especially in treating those with higher expectations and demands. Treatment duration and the amount of residual alveolar bone available are often important considerations when planning for dental implant-based fixed treatment for these patients. With the introduction of zygomatic implants, a graftless alternative solution has emerged for deficient maxillary bone with provision for immediate loading. This article describes the treatment of a completely edentulous elderly patient using zygomatic implants in conjunction with conventional implants. The implants were immediately loaded using a definitive acrylic resin fixed denture reinforced with a cast metal framework, to provide function and aesthetics., (© 2011 The Gerodontology Society and John Wiley & Sons A/S.)

Background: The clinical success of relining depends on the ability of reline resin to bond to denture base. Surface preparations may influence reline bond strength of urethane-based dimethacrylate denture base resin., Aim: To investigate the effect of bur preparation on the surface roughness (R a ) of eclipse denture base resin and its shear bond strength (SBS) to an intra-oral self-curing reline material. The mode of reline bonding failure was also examined., Materials and Methods: Twenty-four cylindrical Eclipse™ specimens were prepared and separated into three groups of eight specimens each. Two groups were subjected to mechanical preparation using standard and fine tungsten carbide (TC) burs and the third group (control) was left unprepared. The R a of all specimens was measured using a contact stylus profilometer. Subsequently, relining was done on the prepared surface and SBS testing was carried out a day later using a universal testing machine., Results: One-way ANOVA revealed significant differences (P<0.05) in R a and SBS values for all the groups. Post-hoc Tukey's HSD test showed significant differences (P<0.05) between all the groups in the R a values. For SBS also there were significant differences (P<0.05), except between standard bur and control., Conclusions: 1) There was a statistically significant difference in the R a of Eclipse™ specimens prepared using different carbide burs (P<0.05). 2) There was a statistically significant difference in the relined SBS (P<0.05) when prepared using different burs, but the difference between the standard bur and the control group was not statistically significant.

Objective: To investigate the effect of cavity preparation on the flexural strength of heat-curing denture resin when repaired with an auto-curing resin., Material and Methods: Ninety-six rectangular specimens (64 x 10 x 2.5 mm) prepared from heat-curing denture base resin (Meliodent) were randomly divided into four groups before repair. One group was left intact as control. Each repair specimen was sectioned into two; one group was repaired using the conventional repair method (Group 1). Two groups had an additional transverse cavity (2 x 3.5 x 21.5 mm) prepared prior to the repair; one repaired with (Group 2) and one without glass-fiber reinforcement (Group 3). A three-point flexural bending test according to the ISO 1567:1999 specification 8 for denture base polymers was carried out on all groups after 1, 7 and 30 days of water immersion. Statistical analysis was carried out using two-way ANOVA, Kruskal Wallis and post-hoc Mann Whitney tests., Results: The highest flexural strength was observed in the control group. Control and conventional repairs group (Group 1) showed reduction in the flexural strength 30 days after water immersion. No significant change in the strength was observed for Groups 2 and 3 where the repair joints were similarly prepared with additional transverse cavity., Conclusion: Repaired specimens showed lower flexural strength values than intact heat-curing resin. Cavity preparation had no significant effect on the flexural strength of repair with water immersion.

Purpose: This study evaluated the shear bond strengths of light-polymerized urethane dimethacrylate (Eclipse) and heat-polymerized polymethylmethacrylate (Meliodent) denture base polymers to intraoral and laboratory-processed reline materials., Materials and Methods: Thirty disks measuring 15 mm diameter and 2 mm thick were prepared for each denture base material following the manufacturers' recommendation. They were relined with Meliodent RR, Kooliner, and Secure reline materials after 1 month of water immersion. Ten additional Eclipse specimens were relined using the same Eclipse resin. A shear bond test was carried out on an Instron machine at a crosshead speed of 1.0 mm/min 24 hours after relining. Data were analyzed using two-way and one-way ANOVAs and post hoc Dunnett's T3 test (p= 0.05). The nature of failure was analyzed under a stereomicroscope. The effect of dichloromethane adhesive on the two denture polymer surfaces and the failed interfaces of mixed and adhesive failures were analyzed under a SEM (scanning electron microscope)., Results: Two-way ANOVA showed significant differences in the shear bond strength values as a function of the denture base polymers, reline materials, and their interaction (p < 0.05). One-way ANOVA showed significant differences in shear bond strength values among denture base-reline combinations (p < 0.05) except for Meliodent-Kooliner and Eclipse-Meliodent RR relines. Meliodent showed the highest shear bond strength value when relined with Meliodent RR (14.5 +/- 0.5 MPa), and Eclipse showed the highest value with Eclipse relining (11.4 +/- 0.6 MPa). Meliodent denture base showed adhesive, cohesive, and mixed failure, while all Eclipse showed adhesive failure with various reline materials., Conclusion: The two chemically different denture base polymers showed different shear bond strength values to corresponding reline materials.

Purpose: This study compared the surface hardness, flexural strength, and flexural modulus of a light- and heat-cured urethane dimethacrylate (UDMA) to two conventional polymethyl methacrylate (PMMA) denture base resins. The effect of less-than-optimal processing condition on the hardness of internal and external surfaces of UDMA specimens was also investigated., Materials and Methods: The materials tested were Eclipse (light- and heat-cured UDMA), Meliodent (heat-cured PMMA), and Probase Cold (auto-cured PMMA). Eclipse specimens were prepared by adapting the material onto the master cast and light curing in the processing unit for 10 minutes. Meliodent and Probase Cold specimens were prepared according to the manufacturers' instructions. Twenty rectangular specimens measuring 65 x 10 x 2.5 mm(3) were prepared for each material. They were stored in water at 37 degrees C for 30 days before testing. The surface hardness was measured using Vickers Hardness (VHN) test, and flexural strength and flexural modulus were measured using a 3-point bending test. Twenty-five additional Eclipse specimens were similarly prepared and were processed at various times of less than 20 minutes of curing. Vickers Hardness was determined on both the external and internal surfaces of specimens. Data were analyzed using a one-way ANOVA for comparisons of hardness, flexural strength, and flexural modulus between the three denture base materials and for hardness values of both the internal and external surface of Eclipse specimens with curing times. Post hoc analyses (Scheffé test) determined the difference between the groups. Student t-test was used for comparison of hardness between the external and internal surfaces of Eclipse specimens., Results: The hardness (VHN) values were 19.4 +/- 0.7, 17.0 +/- 0.4, and 16.0 +/- 0.4; the flexural strengths (MPa) were 103 +/- 4, 78 +/- 3, and 63 +/- 4; and the flexural moduli (MPa) were 2498 +/- 143, 1969 +/- 55, and 1832 +/- 89 for Eclipse, Meliodent, and Probase Cold materials, respectively. A comparison among the three polymers showed there were significant differences in surface hardness, flexural strength, and flexural modulus (p < 0.05). No significant difference in surface hardness (VHN) between the internal (19.1 +/- 0.6 to 19.4 +/- 0.7) and external surfaces (18.9 +/- 0.4 to 19.2 +/- 0.6) of irradiated Eclipse specimens was observed at 10-, 12-, and 14-minute polymerization times., Conclusion: The surface hardness, flexural strength, and flexural modulus of light- and heat-cured UDMA (Eclipse) were significantly higher than the values obtained for heat-only cured (Meliodent) and auto-cured (Probase Cold) PMMA denture base systems.

Objective: To summarize the data and look into the various treatments offered to cervical cancer patients at Institute of Nuclear Medicine and Oncology (INMOL) to highlight the most likely causes of treatment failure., Methods: In this retrospective study, case files of all patients presenting with invasive carcinoma of uterine cervix during 1993-2002 were studied in respect to personal profile, disease related risk factors, pathological characteristics, treatment administered and outcome in the form of tumour response and survival., Results: Early age at marriage, multiple marriages of self or spouse, multiparty, prolonged use of contraceptives and smoking were some of the risk factors for cervical cancer in this group of patients. Out of 618 patients presenting with invasive cervical cancer, 65% presented in advanced stages II and III. Apart from advanced stage at presentation, anaemia, poor nutrition, and ignorance about self-hygiene and lack of follow-up were main causes of treatment failure. Outcome of treatment was improved when chemotherapy was added to radiation., Conclusion: Advanced stage at diagnosis and lack of follow-up were main causes of treatment failure. Implementation of screening programs on national level for early detection is therefore recommended.

Nylon denture base material could be a useful alternative to poly (methyl methacrylate) (PMMA) in special circumstances such as patient allergy to the monomer. The aim of this study was to evaluate the flexural properties of a nylon denture base material (Lucitone FRS), a conventional compression-moulded heat-polymerized (Meliodent), a compression-moulded microwave-polymerized (Acron MC) and an injection-moulded microwave-polymerized (Lucitone 199) PMMA polymers. The effect of aldehyde-free, oxygen releasing disinfectant solution (Perform) on these properties was also investigated. The flexural modulus and the flexural strength were assessed with a three-point bending test. Specimens were stored in water at a temperature of 37 degrees C for 30 days. For each material, half of the prepared specimens were randomly selected and immersed in the disinfectant 24 h prior to testing. Results were compared statistically at a confidence level of 95%. The result showed that in both the control and disinfected groups, the flexural modulus of nylon was significantly lower than the three PMMA polymers. The flexural strength of nylon was significantly lower than those of Meliodent and Acron MC but was comparable with Lucitone 199. A 24-h immersion in the disinfecting solution increased the rigidity of nylon denture base material.

This article describes the occlusal rehabilitation of a partially edentulous patient who did not want a removable partial denture. Implants and extensive fixed restorations were used to restore posterior support and treat severely worn dentition, respectively. The treatment offered the patient a functional and esthetic result.

Purpose: The impact strength and the flexural properties of denture base materials are of importance in predicting their clinical performance upon sudden loading. This study compares the impact and transverse strengths and the flexural modulus of three denture base polymers., Materials and Methods: The investigation included a relatively new microwave-polymerized polyurethane-based denture material processed by an injection-molding technique, a conventional microwave-polymerized denture material, and a heat-polymerized compression-molded poly(methyl methacrylate) (PMMA) denture material. Impact strength was determined using a Charpy-type impact tester. The transverse strength and the flexural modulus were assessed with a three-point bending test. The results were subjected to statistical analysis using a one-way analysis of variance and the Scheffé test for comparison., Results: The impact strength of the microwave-polymerized injection-molded polymer was 6.3 kl/m2, while its flexural strength was 66.2 MPa. These values were lower than those shown by the two compression-molded PMMA-based polymers. The differences were statistically significant. The flexural modulus of the new denture material was 2,832 MPa, which was higher than the conventional heat-polymerized polymer but was comparable to the other microwave-polymerized PMMA-based polymer. The difference in the flexural modulus was statistically significant., Conclusion: In terms of the impact and flexural strengths, the new microwave-polymerized, injection-molded, polyurethane-based polymer offered no advantage over the existing heat- and microwave-polymerized PMMA-based denture base polymers. However, it has a rigidity comparable to that of the microwave-polymerized PMMA polymer.

The degree of polymerization of an acrylic resin repair material, as established by residual monomer estimation, was compared using three different polymerization methods, i.e. bench-cure, hydroflask-cure and microwave irradiation cure. The repair strength of a conventional heat-polymerized resin was then assessed following repairs using each of these three methods. The lowest level of residual monomer was achieved with the microwave irradiation cure. It was also demonstrated that of the three methods, polymerization using microwave energy resulted in the strongest repair.