Evaluation of pH and calcium ion release in capseal I and II and in two other root canal sealers.

OBJECTIVE: The aim of this study was to compare the pHs and calcium ion releases of newly developed, calcium phosphate-based root canal sealers (Capseal I and II) with those of Sealapex (SA) and Sankin Apatite Root Sealer III (SARS III). STUDY DESIGN: Each material (n = 10) was mixed, inserted into polyvinyl chloride (PVC) tubes, and immersed in a vial containing deionized water. The control group consisted of empty PVC tubes (n = 10). The pHs and calcium ion releases were measured by pH meter and ICP-AES (inductively coupled plasma atomic emission spectrometer) at 24 hours and 96 hours, and at 7, 15, and 28 days. The results were analyzed with the Kruskal-Wallis test. RESULTS: Capseal I and II produced pHs and calcium ion releases higher than or equal to those of SA and SARS III (P < .05). CONCLUSIONS: Capseal I and II resulted in higher alkalinity and higher calcium ion releases than SA and SARS III.

Effects of blood contamination on microtensile bond strength to dentin of three self-etch adhesives.

This study evaluated the effects of blood contamination and decontamination methods during different steps of bonding procedures on the microtensile bond strength of two-step self-etch adhesives to dentin. Sixty extracted human molars were ground flat to expose occlusal dentin. The 60 molars were randomly assigned to three groups, each treated with a different two-step self-etch adhesive: Clearfil SE Bond, AdheSE and Tyrian SPE. In turn, these groups were subdivided into five subgroups (n = 20), each treated using different experimental conditions as follows: control group-no contamination; contamination group 1-CG1: primer application/ contamination/primer re-application; contamination group 2-CG2: primer application/contamination/wash/dry/primer re-application; contamination group 3-CG3: primer application/adhesive application/light curing/contamination/ adhesive re-application/light curing; contamina- tion group 4-CG4: primer application/adhesive application/light curing/contamination/wash/ dry/adhesive re-application/light curing. Composite buildup was performed using Z250. After 24 hours of storage in distilled water at 37 degrees C, the bonded specimens were trimmed to an hourglass shape and serially sectioned into slabs with 0.6 mm2 cross-sectional areas. Microtensile bond strengths (MTBS) were assessed for each specimen using a universal testing machine. The data were analyzed by two-way ANOVA followed by a post hoc LSD test. SEM evaluations of the fracture modes were also performed. The contaminated specimens showed lower bond strengths than specimens in the control group (p < 0.05), with the exception of CG1 in the Clearfil SE group and CG2 and CG3 in the Tyrian SPE group. Among the three self-etch adhesives, the Tyrian SPE group exhibited a significantly lower average MTBS compared to the Clearfil SE Bond and AdheSE (p < 0.05) groups. Based on the results of the current study, it was found that blood contamination reduced the MTBS of all three self-etch adhesives to dentin, and water-rinsing was unable to overcome the effects of blood contamination.

In vitro evaluation of bacterial leakage resistance of an ultrasonically placed mineral trioxide aggregate orthograde apical plug in teeth with wide open apexes: a preliminary study.

OBJECTIVE: The purpose of this study was to compare the sealing ability of an ultrasonically placed orthograde mineral trioxide aggregate (MTA) apical plug in open apices. STUDY DESIGN: Thirty extracted human maxillary incisors were used. Experimental teeth were instrumented up to #100 file at the apex, and the 5 mm MTA apical barrier was placed with (group A; n = 11) or without (group B; n = 11) ultrasonic activation. Eight teeth served as control group. Bacterial leakage was assessed daily for 180 days using a double-chamber bacterial leakage model with Enterococcus faecalis. The results were analyzed with Fisher exact test. RESULTS: After 60 days, the ratio of leaked samples showed significant difference between groups A (2 out of 10) and B (8 out of 11) (P < .05). The mean time elapsed before leakage showed significant difference between groups A (158 days) and B (23 days) (P < .05). CONCLUSIONS: Ultrasonically placed orthograde MTA apical plugs were effective at delaying bacterial leakage.

Immediate implant placement into infected and noninfected extraction sockets: a pilot study.

OBJECTIVE: This study compared the osseointegration of immediate implants in dogs in infection-free sites and in sites with periradicular lesions which were removed by simulated periradicular surgery. STUDY DESIGN: Periradicular surgeries were performed to remove intentionally induced periradicular lesions, followed by teeth extraction and immediate implant placement with (experimental group 1) or without (experimental group 2) membranes. In the control group, implants were placed at healthy extraction sockets. After 12 weeks, the animals were killed and the results of histomorphometric study were analyzed by Kruskal-Wallis test. RESULTS: Both the control and the experimental implants were clinically acceptable. The control group showed significantly higher bone-implant contact (BIC; 76.03 +/- 7.98%) than the experimental groups 1 (59.55 +/- 14.21%) and 2 (48.62 +/- 20.22%) (P < .05). CONCLUSIONS: Despite the lower BIC of the experimental groups, this pilot study showed the possibility that immediate implant placement might be successful in extraction sockets with periradicular lesions. Further studies with larger sample sizes are required.

The effect of MTAD on the coronal leakage of obturated root canals.

The purpose of this study was to evaluate the effect of smear-layer removal using MTAD on coronal leakage of obturated root canals using a dye-leakage test. Fifty, extracted, single-rooted, human teeth were cleaned and shaped and divided into 5 equal groups of 10 each. The smear layer in groups 1 to 3 was left intact. The smear layer in groups 4 and 5 was removed using 17% EDTA or MTAD, respectively. After obturation of root canals, the access opening to each canal was filled with India ink for 48 h. The depth of coronal-dye penetration was measured using the Sigmascan software. ANOVA showed statistically significant differences among the groups (p < 0.05). Samples treated with MTAD yielded significantly less leakage than samples treated with sodium hypochlorite. The amount of dye penetration was not statistically different between teeth treated with MTAD or EDTA (p = 0.062).