Evaluation of efficacy of Aloe Vera as a Disinfectant by Immersion and Spray methods on Irreversible Hydrocolloid Impression Material and its Effect on the Dimensional Stability of Resultant Gypsum Cast - An in Vitro Study.

The need to use a natural alternative for disinfecting dental impression materials, which should be biocompatible and effective, led us to evaluate the efficacy of Aloe vera as a disinfectant by immersion and spray method on alginate impression material and its effect on the dimensional stability of the resultant gypsum cast. The efficacy of the disinfection procedures against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans was evaluated by determining the number of colony-forming units (CFU) recovered after disinfection of alginate discs inoculated with 1x106 CFU for defined intervals with aloe vera solution (99.96%). Dimensional stability was determined from the mean percentage deviation of three measurements that were taken between the fixed points on the casts using a traveling microscope and compared with corresponding measurements from the master model and controls. Statistical analysis of data was determined by analysis of variance. We found out that there is a mean percentage reduction in colony count of S. aureus, P. aeruginosa, and C. albicans after 3 minutes of immersion in aloe vera and after 3 minutes spray disinfection. Complete elimination of all the microorganism cells after 7 min immersion and spray disinfection. There was a statistically significant difference in the increase of the mean anteroposterior (AP) and cross arch (CA) dimension after 3 and 7 minutes immersion in aloe vera. Spraying with aloe vera for 7 minutes was proved to be the most effective disinfection procedure without altering dimensional stability.

A Clinical Study to Examine the Effect of Complete Denture on Head Posture/Craniovertical Angle.

INTRODUCTION: Edentulous patients show some significant changes in ridge relationship caused by resorption of alveolar ridge. The changes are characterized by an upward rotation of mandible, increase in mandibular prognathism that ultimately results in change of natural head posture. AIM: This clinical study was planned to know the effect of complete denture on head posture in different age groups of Indian completely edentulous population, after placement of complete denture at various time intervals. MATERIALS AND METHODS: The sample consisted of completely edentulous patients without previous experience of the dentures. They were divided into 2 age groups: Group A (45-60) and Group B (61-75). During placement of complete denture craniovertical angle was measured with the help of custom made ruler protector device. Readings were taken before denture placement, immediately after denture placement, 30 minutes, 24 hours and 30 days after dentures placement. RESULTS: The results of this study indicated that in most of the patients (90%) despite their age, change in head posture (extension) occurred immediately after the denture placement. Thereafter reading remains same for measurement at 30 minutes and 24 hours of denture placement. However after 30 days, observation revealed that all the patients showed reduced craniovertical angle (flexion). Even though the values of craniovertical angle remain higher than its baseline in both groups, significant changes were noticed only in Group A. CONCLUSION: Findings revealed that head posture was significantly altered by the placement of dentures in completely edentulous patients. Within the time interval of 30 minutes and 24 hours extension of head posture remained constant with slight variation. Although after 30 days, changes remained significant for group 'A', but no significant changes were observed in the subjects of group 'B'.

A clinical study to compare between resting and stimulated whole salivary flow rate and pH before and after complete denture placement in different age groups.

PURPOSE: This study compared the flow rate and pH of resting (unstimulated) and stimulated whole saliva before and after complete denture placement in different age groups. MATERIALS AND METHODS: Fifty healthy, non-medicated edentulous individuals of different age groups requiring complete denture prostheses were selected from the outpatient department. The resting (unstimulated) and stimulated whole saliva and pH were measured at three stages i.e., i)Before complete denture placement;ii)Immediately after complete denture placement; andiii)After 2 to 3 months of complete denture placement. Saliva production was stimulated by chewing paraffin wax. pH was determined by using a digital pH meter. RESULTS: Statistically significant differences were seen in resting(unstimulated) and stimulated whole salivary flow rate and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No statistically significant differences were found between the different age groups in resting (unstimulated) as well as stimulated whole salivary flow rate and pH. CONCLUSION: Stimulated whole salivary flow rates and pH were significantly higher than resting (unstimulated) whole salivary flow rates and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No age related variations in whole salivary flow rate and pH were observed in healthy, non-medicated individuals. CLINICAL IMPLICATIONS: The assessment of salivary flow rate, pH in different age groups is of prognostic value, which is an important aspect to be considered in the practice of removable prosthodontics.

Techniques for dental implant nanosurface modifications.

PURPOSE: Dental implant has gained clinical success over last decade with the major drawback related to osseointegration as properties of metal (Titanium) are different from human bone. Currently implant procedures include endosseous type of dental implants with nanoscale surface characteristics. The objective of this review article is to summarize the role of nanotopography on titanium dental implant surfaces in order to improve osseointegration and various techniques that can generate nanoscale topographic features to titanium implants. MATERIALS AND METHODS: A systematic electronic search of English language peer reviewed dental literature was performed for articles published between December 1987 to January 2012. Search was conducted in Medline, PubMed and Google scholar supplemented by hand searching of selected journals. 101 articles were assigned to full text analysis. Articles were selected according to inclusion and exclusion criterion. All articles were screened according to inclusion standard. 39 articles were included in the analysis. RESULTS: Out of 39 studies, seven studies demonstrated that bone implant contact increases with increase in surface roughness. Five studies showed comparative evaluation of techniques producing microtopography and nanotopography. Eight studies concluded that osteoblasts preferably adhere to nano structure as compared to smooth surface. Six studies illustrated that nanotopography modify implant surface and their properties. Thirteen studies described techniques to produce nano roughness. CONCLUSION: Modification of dental osseous implants at nanoscale level produced by various techniques can alter biological responses that may improve osseointegration and dental implant procedures.

A clinical study to determine the pattern of occlusal contacts in lateral positions and its validity in classifying guidance patterns.

The existing classification systems like canine-guided and group function are insufficient to classify all clinical conditions and chances of subjective variations are always there, as there is no standardization in examination method. Hence a study was planned to find out the frequency of tooth contacts in different lateral positions and to assess whether existing occlusal schemes like canine protection and group function can classify all occlusal guidance in the natural dentition. 100 systematically healthy undergraduate students between the age group of 18 to 25 years were selected. Occlusal contacts were examined with shim stock in lateral positions, 0.5, 1, 2, and 3 mm from the maximum intercuspation. Frequency of tooth contacts in different lateral positions was examined. The SPSS version 15.0 statistical software and Chi- Square test were used for statistical analysis. Out of all the four lateral positions, 0.5 mm position showed maximum contacts which progressively decreases for further positions. Out of all teeth, canine showed consistent contact frequency throughout all four positions. Most contact patterns belonged to group function, and a few to canine protection. Majority of the contact patterns were those other than canine protection and group function and were unclassifiable. On the basis of the results of this study, it does not seem appropriate to describe and classify the patterns of occlusal contact using only existing classification system. A clear description regarding the position of mandible should be included in definition for research as well as clinical situations. Here an attempt is made to classify eccentric occlusal contact at different lateral positions so as to get consistent result for future studies.

Effect of five brands of latex gloves on the setting time of polyvinyl siloxane putty impression materials.

Addition silicone impression materials have been used as impression material for more than 20 years. Although they are among the most expensive impression materials, they became popular during the past decade as they have excellent physical properties. Prevention of infection is an important aspect in dental treatment since dental professionals are routinely exposed to the wide variety of microorganisms present in saliva. Gloves are the most common protective measure used during dental treatment. The gloves are mostly made of latex. In this study, we examine how the setting time of three types polyvinyl putty materials were affected by the use of five different brands of latex gloves and one brand of vinyl gloves. Each material was first mixed without wearing gloves according to the manufacturer's instructions. After the stipulated mixing time, the setting time was measured using the Vicat needle. The setting time is measured from the time of mixing till the time that the needle does not produce any indentation on the surface of the material. The putty material was then mixed with gloved hands (using the five different brands of latex gloves in turn) and the setting time was measured. Then the material was mixed with washed gloved hands, and the setting time was measured again. Finally, the material was mixed with vinyl gloved hands and the setting time was measured. The following conclusions were drawn from the study: Reprosil and Express showed significant variation in the setting time with the latex gloved hands.There was no significant variation in the setting time when material was mixed with unwashed vs washed gloved hands.Vinyl gloves did not significantly affect the setting time of any of the putty impression materials.

Application of Botulinum toxin type A: an arsenal in dentistry.

An extremely effective way of preventing damage to and enhancing treatment of dental hard tissues and restorations would be to ''de-programme'' the muscles responsible for excessive destructive forces and other gnathological-related diseases. The new paradigm is the intramuscular injection of Botulinum toxin type A (BOTOX) into the affected muscles. It is a natural protein produced by anaerobic bacterium, Clostridium botulinum. The toxin inhibits the release of acetylcholine (ACH), a neurotransmitter responsible for the activation of muscle contraction and glandular secretion, and its administration results in reduction of tone in the injected muscle. There are seven distinct serotypes of Botulinum toxin, viz., A, B, C, D, E, F, and G, which differ in their potency, duration of action, and cellular target sites. This paper describes the different applications of BOTOX in dentistry.

Comparison of manual and physiologically molded denture bases in complete denture wearers.

BACKGROUND AND OBJECTIVES: In complete denture wearers, the accumulation of food in the buccal vestibule is one of the factors causing discomfort to the patient. This study was conducted to evaluate the effect of mandibular denture buccal flange on food retention and to correlate between varying angulations of buccal flange of mandibular denture on food retention. MATERIALS AND METHODS: Complete dentures were fabricated and the mandibular complete denture was duplicated. The existing (unduplicated) manually molded and physiologically molded dentures were tested for food retention. Twenty test particles having a diameter of 2±0.2 mm were placed on the middle part of the buccal flange and the subjects were instructed to expel the test particles by performing only functional movements of the buccal musculature. The numbers of residual test particles in the buccal vestibule were counted after 30s. The angulations of the denture buccal flange (duplicated) were measured with an optical bevel protractor and trimmed to 50° and the food retention test was performed. Similar tests were performed at 60°, 70° and 80° angulations. The data were evaluated using the Pearson correlation coefficient, One-way ANOVA test and Wilcoxon signed rank test. RESULTS: The difference between the residual scores of manually molded and physiologically molded denture base was not significant. The difference between the residual scores at different angulations of the buccal flange of the denture was significant. CONCLUSION: Only the slope of the flange significantly affects the ability of subjects to expel the test particles.