Search

Shie MY, Chang HC, Ding SJ. Effects of altering the Si/Ca molar ratio of a calcium silicate cement on in vitro cell attachment. International Endodontic Journal, 45, 337-345, 2012. Abstract Aim To examine the effects of altering the Si/Ca molar ratio (6 : 4, 5 : 5, and 4 : 6) of a quick-setting calcium silicate cement on in vitro cell attachment. Methodology Working time and setting time of three different calcium silicate cements were measured. Alamar Blue was used for real-time and repeated monitoring of cell attachment and proliferation. The Si and Ca ion concentrations of the cell culture medium in the presence of three different calcium silicate cements seeded with MG63 cells were measured. Kinetic immunofluorescent staining of MG63 cells was performed during cell attachment and spreading. Reverse transcription-polymerase chain reaction was employed to determine gene expression in MG63 cells cultured on the cements. One-way analysis of variance was used to evaluate the significance of the differences between the mean values. Results The working time (4-7 min) and setting time (17-24 min) of the cements were shortened with an increase in the Ca content of the calcium silicate powders after mixing the powder with water. In contrast, the higher the Si content in the cement, the more the MG63 cells attached to the cement at all culture time-points, accompanying by the formation of more obvious actin stress fibres. Cell proliferation and differentiation increased significantly ( P < 0.05) with an increase in the Si content of the calcium silicate cements. Si ion concentration of the culture medium increased significantly ( P < 0.05) with increasing cement Si content and culture time-points. Conclusions The higher Si content cement enhanced the higher expression of cell attachment, proliferation and differentiation as compared to the lower Si content cement. [ABSTRACT FROM AUTHOR]

Aim To determine the types of periapical lesions associated with root filled teeth with persistent periapical pathosis that required surgical treatment based on specific inclusion and exclusion criteria. Methodology Periapical lesions from a consecutive clinical sample of 100 patients were examined histopathologically to determine a definitive diagnosis. Results Females were more represented ( n = 56), the average age was 46.5 years and there were no age differences between gender or lesion type. A diagnosis of periapical granuloma was the most common finding with a similar number present in females ( n = 40) and males ( n = 37). A cyst was present in 18% of the cases with a majority of females ( n = 12) represented in the sample. Evidence of foreign material, with an appearance consistent with endodontic sealer materials, was seen in 25 periapical granulomas, two cysts and one scar. Two periapical scars were seen, one had a history of apicectomy and amalgam root-end filling while the other was associated with extruded root filling material. Conclusions By using defined clinical inclusion and exclusion criteria a predictable clinical diagnosis of a persistent periapical lesion due to endodontic origin can be reliably made. Periapical granulomas and cysts were the most common periapical lesions of endodontic origin associated with persistent periapical pathosis with the overall incidence of periapical cysts similar to previous studies. The presence of endodontic material in a high proportion of periapical lesions suggests a cause-effect association with the inference that clinicians should employ canal preparation techniques that limit apical extrusion of material. [ABSTRACT FROM AUTHOR]