Jean-François Roulet

Pulp Capping of Carious Exposures: Treatment Outcome after 5 and 10 Years: A Retrospective Study

One hundred twenty-three pulp cappings had been performed by students in 1984 to 1987 (= 10-yr group) or in 1990 to 1992 (= 5-yr group) and were followed up in 1997. Teeth were checked for sensitivity (CO2/electrical pulp testing), percussion, and palpation; radiographs were taken to assess periapical status. In addition several other factors were determined that might have an influence on the success or failure rates, such as base material, type of restoration, site of exposure, etc. Results showed 44.5% failures (18.5% questionable and 37% successful cases) in the 5-yr group and 79.7% failing, 7.3% questionable, and 13% successful cases in the 10-yr group. As a factor of influence, the placement of a definitive restoration within the first 2 days after pulp exposure was found to contribute significantly to the survival rate of these teeth.

Leakage in roots coronally sealed with different temporary fillings

This study was aimed at determining the ability of different coronal temporary fillings to prevent corono-apical penetration of bacteria. A total of 103 human teeth, including three controls, were instrumented, obturated with gutta-percha, coronally sealed with either Cavit, Intermediate Restorative Material (IRM), glass-ionomer cement, Cavit/glass-ionomer cement, or IRM/glass-ionomer cement, respectively. Each root was fixed with wax between two chambers: the coronal chamber harboring soy broth with 10(8) colony-forming units of Streptococcus mutans/ml, the apical chamber containing sterile soy broth. The latter was checked daily for turbidity, indicating corono-apical penetration of bacteria. The Cavit group, the IRM group, and the Cavit/glass-ionomer cement group showed significantly more leakage than the glass-ionomer cement group of the IRM/glass-ionomer cement group. If a sample leaked, all except one (IRM/glass-ionomer cement) leaked before day 12. This in vitro study seems to indicate that only glass-ionomer cement and IRM combined with glass-ionomer cement may prevent bacterial penetration to the periapex of root-filled teeth over a 1-month period.

In Situ Antimicrobial Effectiveness of Chlorhexidine and Calcium Hydroxide: Gel and Paste Versus Gutta-Percha Points

The aim of this study was to determine the antibacterial effectiveness of either chlorhexidine or calcium hydroxide integrated in gutta-percha points compared with chlorhexidine or calcium hydroxide delivered as gel or paste, respectively. A total of 70 initially sterile roots with open accesses were carried for 1 week in the oral cavities of two volunteers. The roots were then removed, and samples were taken from the root canals for microbial analysis. The roots were medicated with calcium hydroxide paste, 5% chlorhexidine gel, or a chlorhexidine- or calcium hydroxide-containing gutta-percha point. The accesses were closed with bonding material, and the roots incubated for 1 week. After removal of the antimicrobial agents, roots were again checked for bacterial growth. One thioglycolate-soaked paper point was then introduced into each canal, and roots were incubated for 1 week more to observe bacterial regrowth. After 1 week of medication, the absolute bacterial count revealed significant differences compared with the controls. However, only the chlorhexidine-gel and the calcium hydroxide paste group showed no microbial colonization in a considerable number of samples after 1 and 2 weeks.

Long-Term bacterial leakage along obturated roots restored with temporary and adhesive fillings.

The aim of this study was to examine whether obturated roots combined with several adhesive and temporary filling materials can be bypassed by bacteria. Standardized cavities were coronally prepared into 130 straight roots mimicking clinical access cavities. After obturation the roots were assigned to six test and three control groups and coronally sealed with either Clearfil, CoreRestore, IRM, Ketac Fil, or a combination of IRM/wax or Ketac Fil/wax. The roots were then fixed between a top and a bottom chamber each. The top chamber contained soy broth with 108 Staphylococcus epidermidis colony-forming units/ml, and the bottom chamber contained sterile soy broth. For 1 yr the mounts were checked on a regular basis for turbidity in their bottom chambers indicating bacterial growth. After 1 yr only three samples from the CoreRestore group and two samples from the Clearfil group resisted leakage. At termination there was no significant difference in number of leaking samples among the groups. At the beginning of the experiment IRM performed worst. Between months 5 and 10 Clearfil showed the least leaking samples; for some months this was statistically significant compared with IRM or Ketac Fil.

A new method to assess the results of instrumentation techniques in the root canal

In the present study, the shape of the root canal was assessed with pre- and postinstrumentation silicone impressions. Curved root canals of 30 extracted molars were instrumented with the Canal Leader (CL), the ProFile System (PF), and hand instrumentation (HI). Photographs from each impression were digitized, and the enlargement of the canals was computed by substracting the preinstrumentation from the postinstrumentation images. Technical errors of preparation were also recorded. There was no significant difference in total dentin removal between the systems. However, CL removed significantly more dentin from the convex side of the root canal than PF. Instrument separation occurred in five cases, only with PF. Roughness of canal walls was recorded significantly more often with the use of CL than with PF or HI. CL also produced a significantly higher incidence of elbow formation, compared with PF or HI. With this method of assessment, it was possible to record details and differences between the tested instrumentation techniques.

Dye penetration in root canals filled with AH26 in different consistencies

It is recommended that the powder to liquid ratio of AH26 be very high and that the mixture be warmed to decrease viscosity before insertion into the root canal. In this study, the effectiveness of the powder to liquid ratio and temperature were assessed using 60 root canals of maxillary central incisors randomly divided into four groups after their cleaning and shaping. The teeth were obturated by either lateral condensation or the single-cone technique using AH26 warmed or at room temperature. After exposure to basic fuchsin, the teeth were embedded and cross-sectioned using a diamond saw. The dye penetration was measured microscopically and reported as a percentage of the total circumference of the filling of each slice using a goniometric eye-piece. After statistical analysis, it was concluded that AH26 in combination with lateral condensation leads to less leakage when used at room temperature.