ABSTRACT
The purpose of this in vitro study was to characterize the interface of glass ionomer sealer and dentine conditioned with common endodontic irrigants through scanning electron microscope. The interface between Ketac-Cem radiopaque glass ionomer sealer and elephant tusk dentine conditioned with distilled water, citric acid and phosphoric acid was investigated. Cylinder of glass ionomer sealer was formed on the conditioned dentine surface and allowed to set for 60 minutes. The specimens were first shear tested to failure to determine their adhesive bond strength. Three debonded dentine specimens from each group were then processed for scanning electron microscopic study. The test failed surface of the strongest, intermediate and weakest bond strength specimens were examined. The specimens were cross sectioned and the interface was examined. The microscopic detail of the debonded interfaces between glass ionomer sealer and dentine was assessed in this study. Failures in all of the specimens were found to be mainly cohesive in nature
Subject(s)
Microscopy, Electron , DentinABSTRACT
To assess the effect of denture wearing on oral candidal activity through candida selective medium inoculated with standardized dilution salivary samples obtained from denture wearers. A cross sectional, comparative study during March-September 2007 was conducted at Khyber College of Dentistry Peshawar. Using a structured proforma, data were collected from 50 subjects [50 Denture wearers]. Stimulated salivary samples were collected from each subject. One ml of standard dilution saliva was mixed with 4ml sterile liquid candida -selective medium. The extent of candida activity was then determined, biochemically, through change in pH of the medium 24 hrs after inoculation and incubation at 37°C. Pathological candidal activity was seen in denture wearers. However, the association between the denture wearing habit and candidal activity was found significant, meaning that continuous denture wearing always showed a high pH change [t- value of 0.01] and mean pH decrease of 2.2 in continuous denture wearers as compare to 1.6 in only day time wearers. Beside this denture plaque score, type of dentures and denture hygiene maintenance was found to have insignificant association with the candida activity. Within the limits of this study, denture wearing significantly enhanced the pathogenic activity of oral candida. The importance of rest to denture supporting tissue is re-emphasized