Dental implant treatment is an excellent option for prosthetic restoration that is associated with high success rates. Implant stability is essential for a good outcome. The clinical assessment of osseointegration is based on mechanical stability rather than histological criteria, considering primary stability (absence of mobility in bone bed after implant insertion) and secondary stability (bone formation and remodelling at implant-bone interface). The aim of this study was to review the literature on Resonance Frequency Analysis (RFA) as a method for measuring dental implant stability. An online search of various databases was conducted on experimental and clinical research published between 1996 and 2008. The studies reviewed demonstrate the usefulness of RFA as a non-invasive method to assess implant stability. Further research is required to determine whether this system is also capable of measuring the degree of dental implant osseointegration.

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Navarro-Escobar E, González-Rodríguez MP, Ferrer-Luque CM. Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy. Med Oral Patol Oral Cir Bucal. 2010 Jan 1;15 (1):e90-4.http://www.medicinaoral.com/medoralfree01/v15i1/medoralv15i1p90.pdf AbstractAim: To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay. Methodology: Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. Results: The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1% dilution, 2.5% NaOCl (63.39%) and 15% citric acid (53.91%) showed the highest percentage of cell viability (p=0.083). At 0.5% dilution, 2.5% NaOCl again showed the highest cell viability value (48.51%). Conclusions: The irrigating solution with the highest percentage of cell viability was 2.5% NaOCl at both 0.1% and 0.5% dilutions. A very low percentage of cell viability was obtained with 15% citric acid and 5% phosphoric acid at 0.5% dilution.

Objective. To compare the long-term sealing ability of GuttaFlow® using different obturation techniques. Study Design. Three hundred teeth, prepared with a crown-down technique, were divided into thirty experimental groups (n=10) to evaluate the apical and coronal leakage, at 3, 30 and 120 days, of lateral compaction gutta-percha + AH Plus™, lateral compaction gutta-percha + GuttaFlow®, single cone + AH Plus™, single cone + GuttaFlow®, and GuttaFlow® only. Results. Both coronal and apical leakage, at the three times of measurement, no significant differences were found among GuttaFlow® + lateral compaction gutta-percha and GuttaFlow® + single cone groups, whereas the only GuttaFlow® reached the highest leakage values at 30 and 120 days. AH Plus™, using both techniques, showed high levels of leakage after 120 days to the coronal leakage and after 30 days to the apical leakage when compared silicon based sealer. Conclusion. GuttaFlow®, using with lateral compaction and single cone techniques, shows a greater apical and coronal sealing ability than AH Plus™ over time. GuttaFlow® when used as only creates a poorer sealing than when used with lateral compaction gutta-percha or single cone techniques.

A comparison was made of the apical leakage of three sealers. Fifty single-root human teeth were randomly divided into 5 groups (n = 10; 3 experimental and 2 control). The teeth of the positive-control and experimental groups were instrumented with K-type files to size 45. The experimental groups were obturated by laterally-vertically, condensed gutta-percha with Endomethasone, Top Seal, or RSA sealer cements. The positive-control group was nonobturated and the negative-control group was noninstrumented. The root surfaces were then coated with nail varnish (except the apex in the experimental groups) and immersed in black ink (for 1 week at 37 degrees C). The statistical evaluation of the results obtained by clearing and cross-section techniques showed no significant differences between sealers. Leakage, as determined by the clearing technique, was significantly greater than that quantified by cross-section analysis.