The effect of denture cleansers on resiliency of soft lining materials.

AIM: The present study was undertaken to determine the effect of denture cleansers on resiliency of soft liner. MATERIALS AND METHODS: Two soft liners (Molloplast-B and Refit) and two denture cleansers (Clinsodent and Fittydent) were taken. Cylindrical aluminum dies were constructed of 12 mm length and 8 mm diameter at the ratio of 1.5:1. The samples are tested with Hounsfield tensometer. OBSERVATION AND RESULTS: Effect of both the denture cleansers on the lining materials was shown in the form of Graphs 1 and 2. The elastic recovery of Molloplast B in dry, Fittydent and Clinsodent is comparatively more than refit, but in control group the elastic recovery of both the material is almost equal. CONCLUSION: Heat processed soft liners recover faster/better in a shorter time interval when compared to self-processed liners which takes longer time for the recovery. This time period is very important as the cushioning effect of the soft liner require an elastic recovery between the masticatory strokes. CLINICAL IMPLICATIONS: Greater the softness and better the elastic recovery of the denture soft liner, more effective would be its performance clinically. Silicon based material, such as Molloplast-B, rebounds quickly and would seem preferable to a material that is acrylic based. It is possible that, if the response is too slow or the elastic recovery is less, there may only be a partial recovery of the lining between the masticatory strokes. Progressive thinning of the lining materials might then occur resulting in a reduced cushioning effect.

Fiber technology in space maintainer: a clinical follow-up study.

Various space maintainers are used in pediatric dentistry. However, their construction requires time consuming laboratory procedures. Recently fiber-reinforced composite resin (FRCR) has been introduced for various application in dentistry. Polyethylene fibers appear to have the best properties in elasticity, translucency, adaptability, tenaciousness, resistance to traction and to impact. The purpose of this study was to clinically evaluate the long-term effect of FRCR space maintainer made with Ribbond(®) bondable reinforcement ribbon in children over a period of 18 months. A total of thirty FRCR space maintainers were applied to 30 children between the age group of 6 to 9 years old, follow-up visits were done at 1, 6, 12 and 18 months. The data obtained was subjected to statistical analysis. Maxillary appliances survived more than mandibular appliances. Mean survival time of space maintainer were found to be 12 months (minimum 1 and maximum 18 months). The present study suggested that FRCR space maintainers (Ribbond(®)), which was observed for up to 18 months, can be accepted as a successful alternative to conventional band-loop space maintainer only for short periods.

A comparative evaluation of impact strength of conventionally heat cured and high impact heat cured polymethyl methacrylate denture base resins: an in vitro study.

UNLABELLED: The denture bases made by using polymethyl methacrylates of Acrylic resin family have excellent physical properties, simple to process and easy to reline, rebase and repair. One of the inherent disadvantages of this material is the liability to break during function. The strength assessment of acrylic resins have been made generally by transverse defection tests. AIM: To evaluate the impact strength valves of certain brands of commercially available denture base resins and suggest their suitability. MATERIALS AND METHODS: The denture bases we made using polymethyl methacrylates of acrylic resin family because they have excellent physical properties, simple to process and easy to reline and rebase. Six commercial brands of polymethyl meth- acrylate, namely Stellon (DPI-India), Acralyn-H (Asian Acrylate, India), Trevalon (Dentsply-England), Lucitone 199 (Dentsply/ York division), Acralyn-H (Super Unbreakable), Trevalon HI (Dentsply, Detray division, England) were tested by breaking them using Analog Pendulum (ASTM D 256). RESULTS: From the entire study the maximum impact strength was reported for Acralyn-H super unbreakable (Asian Acrylates, India) 62.19 joules. CONCLUSION: All the analysis led to conclusion that there is basic change in material composition within and among the different groups of denture base resins. CLINICAL IMPLICATIONS: The complete dentures made using denture base resins with high impact strength valves (e.g. Acralyn-H super unbreakable) will be more durable and can be used by the patient for considerable period of time, i.e. beyond 4 to 5 years.

Epidemiological survey on edentulousness.

UNLABELLED: India has a large geriatric population of 77 millions, comprising 7.7% of its total population. One of the major handicaps in the elderly is loss of teeth, affecting their mastication, dietary intake and nutritional status. AIMS AND OBJECTIVES: The present study was planned to assess the level of edentulousness, cause of edentulousness, denture wearing and denture needs of the middle and elderly in the society and study was correlated between habits and socioeconomic variables, diet and body mass index (BMI). MATERIALS AND METHODS: A total of 500 subjects (random sampling) from dental outpatient were studied. A prepared questionnaire was developed, explained, interviewed and questions were filled personally. RESULTS: The level of edentulousness was found to be high in the subjects with low socioeconomic status and in advancing age with no significant difference between male and females. Another finding was very low level of denture wearing of 62% needing complete denture and partial denture only 10.4% of subjects wearing dentures. Mixed diet population had higher level of edentulousness compared with vegetarians. The BMI was correlated with level of edentulousness. CONCLUSION: The study clearly showed that there is lack of dental awareness, so dental education and motivation in very important. The study concludes that the need for prosthodontics care will increase due to the increase in life span. This study is clinically significant with regard to knowing the root cause of edentulism, either partial or complete. Out of 62% tooth loss, dental caries (37.4%) topped the cause for tooth loss followed by combination of dental caries and periodontal disease (12.2%).

A comparative study to determine the wettability and castability of different elastomeric impression materials.

AIM: The aim of this study was to determine the wettability of different hydrophilic and hydrophobic elastomeric impression materials and the gypsum castability. MATERIALS AND METHODS: The wettability was evaluated by determining the contact angles of different elastomeric impression materials. The contact angle was determined by placing a drop of aqueous solution of calcium sulfate dihydrate on the flat surface of impression material and specimens were measured using a profile projector. Gypsum castability was determined by counting the number of voids formed in the die stone cast made from the impressions of a aluminum die. The voids were counted using an diopter magnifying lens. RESULTS: Polyether, different viscosities of polyvinyl siloxane, and condensation silicone impression materials exhibited low contact angle values and least number of voids in the die stone cast when compared with polysulfide impression material. CONCLUSION: There was significant correlation between the contact angle and voids formed in the die stone casts when fabricating die stone casts from various elastomeric impression material impressions. CLINICAL SIGNIFICANCE: Accurate reproduction of prepared tooth or edentulous arch is of clinical importance in the fabrication of a fixed or removable prosthesis. Inaccuracies in the replication processes will ultimately have an adverse effect on the fit and adaptation of final restoration. The interaction is determined in part by hydrophilic and hydrophobic nature of the elastomeric impression material. Inadequate wetting of an impression results in voids in the stone casts.