Susceptibility of a polycaprolactone-based root canal filling material to degradation. I. Alkaline hydrolysis

Comparison of 5.25% Sodium Hypochlorite, MTAD, and 2% Chlorhexidine in the Rapid Disinfection of Polycaprolactone-Based Root Canal Filling Material

The purpose of this investigation was to compare the effectiveness of 5.25% sodium hypochlorite, MTAD, and 2% chlorhexidine in the rapid disinfection of Resilon pellets. Resilon pellets were randomly selected, contaminated with Enterococcus faecalis, and disinfected with 5.25% sodium hypochlorite, MTAD, or 2% chlorhexidine. Positive and negative controls were used. All samples were air dried, washed in sterile water, placed in centrifuge tubes containing BHI broth, and incubated at 37 degrees C for up to 7 days. Broths were visually checked for turbidity and scored for growth. Samples from each experimental and control group were randomly chosen, plated, incubated at 37 degrees C, and checked visually for growth. If growth occurred, a gram stain was performed to identify bacterial species. Results indicate that 5.25% sodium hypochlorite, MTAD, and 2% chlorhexidine were all effective in the rapid disinfection of Resilon and gutta-percha pellets, and a 1-minute immersion was sufficient to disinfect.

The physical characterization of a thermoplastic polymer for endodontic obturation

OBJECTIVE

To analyze a new endodontic sealer material commercially known as Resilon and to describe in detail the experimental techniques employed that lead to the identification of the composite material.

METHODS

An extensive structural, thermal, and physical characterization was used to identify a new endodontic sealer material using the following techniques: Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) analysis, X-ray fluorescence spectrometry (XRF) technique, X-ray diffraction (XRD) measurement, thermo-gravimetric analysis (TGA) and a differential scanning calorimeter (DSC). The surface morphology was analyzed using a scanning electron microscope (SEM).

RESULTS

The material was identified as a composite of polycaprolactone, which is a polymer of the polyester family and bioactive glass, which is radiopaque filler.

CONCLUSIONS

The Resilon sealer material is a thermoplastic synthetic degradable polymer (polycaprolactone), it contains bioactive glass. Its properties, such as strength, modulus, shape-memory effect and biodegradability depend on the crystalline fraction, which is affected in turn by conditions of crystallization. Investigation of the crystallization kinetics of PCL is of practical significance. It is especially necessary to study its the dynamic and non-isothermal crystallization process.

Effects of Sodium Hypochlorite and Chlorhexidine Solutions on Resilon (Synthetic Polymer Based Root Canal Filling Material) Cones: An Atomic Force Microscopy Study

The aim of the present study is to evaluate the effects of 2% chlorhexidine and 5.25% sodium hypochlorite on the surface properties of Resilon cones with the atomic force microscopy. The Resilon cones were immersed in disinfecting agents (5.25% sodium hypochlorite and 2% chlorhexidine) at 1 and 5 min time intervals. Atomic force microscopy was used to evaluate topographical deviations of Resilon cones. Root mean square (RMS) parameters for topographic amplitudes were calculated. The cones exhibited statistically significant low RMS values at 5-min immersion in sodium hypochlorite and chlorhexidine groups compared to the all other groups (p < 0.05). One-minute immersion did not show any significant deterioration on the Resilon surface (p > 0.05). In conclusion, sodium hypochlorite and chlorhexidine solutions used for disinfection significantly decreased (p < 0.05) the RMS values of Resilon cones at 5-min applications.

Efficacy of Retreatment Techniques for a Resin-Based Root Canal Obturation Material

Resilon/Epiphany obturation system is emerging as an alternative to gutta-percha (GP). The efficacy of retreatment techniques for Resilon removal has not been determined. The purpose of this study was to evaluate two commonly used retreatment techniques in the removal of Resilon. Sixty single-canal teeth were instrumented and obturated with either Resilon/Epiphany or GP/AH Plus. Each canal was randomly allocated to receive one of the two retreatment techniques-ProFile 0.06 rotary files combined with heat or chloroform. The time required to remove the obturation material was recorded and the cleanliness of canal walls was determined by stereomicroscope and electron microscopy. The results demonstrated that chloroform combined with rotary files was more efficient in material removal compared to heat (p < 0.05). Resilon was faster to remove than GP. Both techniques resulted in cleaner canal walls in the apical third of the teeth obturated with Resilon when compared to GP (p < 0.05).

Comparison of the Sealing of Resilon, Pro Root MTA, and Super-EBA as Root-End Filling Materials: A Bacterial Leakage Study

The purpose of this in vitro study was to compare the root-end sealing of the Resilon/Epiphany system (RES) to Pro Root MTA and Super-EBA using a bacterial leakage system. Fifty-five extracted teeth were instrumented and root-ends were resected and ultrasonically prepared. Test materials were placed in the root-end preparations; Streptococcus salivarius was introduced coronally and the apical 4 mm were immersed in BHI culture medium with phenol red indicator. Bacterial leakage was monitored every 24 h for 4 wk. All positive controls leaked within 24 h; none of the negative controls leaked. Based on chi2 analysis (p < 0.05), RES and MTA leaked significantly less than Super-EBA. There was no statistical difference between RES and MTA. RES may be a viable option as a root-end filling material with good surgical isolation.

Effectiveness of hand and rotary instrumentation for removing a new synthetic polymer-based root canal obturation material (Epiphany) during retreatment

AIM

To evaluate the effectiveness of hand and rotary instrumentation for removal of vertically compacted Epiphany and gutta-percha during retreatment.

METHODOLOGY

Sixty extracted single-rooted maxillary central incisors were enlarged to size 40 using FlexMaster instruments. The teeth were randomly divided into four groups of 15 specimens each. The canals of two groups were obturated using vertically compacted Epiphany. The others were filled with vertically compacted gutta-percha and AH Plus sealer. One Epiphany group and one gutta-percha group was reinstrumented with Gates Glidden burs and Hedström files. In the other two groups, obturation material was removed using Gates Glidden burs and RaCe rotary instruments. After clearing the roots, the area of remaining obturation material on the root canal wall was measured using a computer image analysis program. Statistical analysis was performed using Repeated Measures Analysis of Variance and anova.

RESULTS

Retreatment of specimens obturated with gutta-percha showed significantly more remaining obturation material than specimens filled with Epiphany (P < 0.05). No difference was found between the removal with Hedström files and with RaCe instruments (P > 0.05). Regarding the mean time of retreatment and time required for reaching the working length, Hedström files were significantly faster than RaCe instruments (P < 0.05). The times did not depend on the kind of obturation material (P > 0.05).

CONCLUSIONS

Vertically compacted Epiphany in combination with Epiphany Root Canal Sealant was removed more effectively than gutta-percha and AH Plus sealer. Hedström files were more rapid than RaCe rotary instruments.