ABSTRACT
Introduction: Fracture of an acrylic resin complete denture base after aging, poses problem for patients, dentists and dental laboratory technicians. This study was performed to determine the effect of thermocycling on the flexural strength of a commercially available, heat-polymerized acrylic denture base material reinforced with glass fibers, carbon fibers, aramid fibers and high (HI) impact resins. Materials and Methods: Forty specimens were made of similar dimension from five groups of materials. Each group had eight specimens. A commercially available heat polymerized P.M.M.A denture base resin was selected as control and PMMA reinforced with glass, carbon, aramid fibres and HI impact resin were compared. All specimens were then subjected to thermocycling before testing. Flexural strength was evaluated with universal testing machine. The results were analyzed with Analysis of Variance (ANOVA) followed by Turkey HSD test. Results: All reinforced specimens and HI impact resins showed better flexural strength than the conventional acrylic resin after thermocycling. Specimens reinforced with glass fibers showed the highest flexural strength, followed by HI impact resin, carbon fibers and aramid fibers. After artificial aging, a significant improvement in the flexural strength of conventional acrylic resin was observed when it was reinforced with glass fibers. Conclusion: Within the limitations of this study, incorporation of 2% by weight of glass fibre in PMMA resin exhibited statistically significant maximum flexural strength followed by high impact resin, carbon, polyaramid reinforced P.M.M.A denture base resin. These can readily be used in the fabrication of dentures subjected to heavy masticatory loads.
ABSTRACT
Aim and Objectives: This study is determined the vertical distance between lingual frenum and incisal edge of mandibular central incisors in dentulous subject and edentulous denture wearer subjects and their variation in different age groups and sex. Materials and Methods: This study involved 120 dentulous subjects (60 men, 60 women) and 20 complete denture wearers. Depending upon the age, the dentulous subjects were divided into three groups. Each group consisted of 40 subjects (20 men, 20 women). Group I consisted of 20-30 yr age, group II 30-4 0yr age and group III consisted of more than 40 yr age. Mandibular impressions of dentulous and denture wearers were made with irreversible hydrocolloid and cast retrieved. The vertical distance between the anterior attachment of lingual frenum and incisal edges of the mandibular central incisors for both the dentulous and edentulous subjects was measured on the casts with the help of dental surveyor. Data were tabulated and stastically analysed. Results: Overall (irrespective of gender) normative range for vertical distance between the anterior attachment of the lingual frenum and mesioincisal edge of mandibular central incisor among dentulous subjects is 9.52-10.24 mm. If we consider gender it is 10.00-11.13 mm for male and 8.82-9.58 mm for female. Conclusion: This study indicated that the distance between the antero-superior most point on the lingual frenum and the mesio-incisal edges of mandibular central incisors can be used as a reliable landmark when the frenum is recorded during function.
ABSTRACT
It is the dentist’s responsibility to fabricate a prosthesis incorporating stability, retention and support which ultimately provide satisfaction to the patient. But in the critical conditions such as long lip length or severely resorbed ridges with increased inter arch distance, the weight of a maxillary denture is often a dislodging factor. Hence, a light weight denture is required for better retention. This article describes a case of completely edentulous patient successfully rehabilitated with a hollow denture where a simplified technique of fabricating a light weight maxillary denture was used.