Primary assessment of a self-adhesive gutta-percha material

To evaluate a prototype gutta-percha material (Bio-Gutta), which is claimed to work without sealer because of its incorporated ultrafine bioactive glass particles, in terms of its induction of pH and calcium phosphate (CaP) precipitates, and its self-adhesiveness in root canals.

Bio-Gutta was compared with conventional gutta-percha (GP, composition: 70 wt% ZnO, 30 wt% polyisoprene). Test and control materials (N = 3) were immersed in phosphate-buffered saline (PBS) at 37 °C for 30 days. The pH in the solution was monitored. Apparent CaP formation was assessed using scanning electron microscopy (SEM). The root canals of 33 single-rooted teeth were filled by vertical compaction of heated Bio-Gutta, 33 control canals were filled with vertically compacted GP without sealer. Push-out bond strengths associated with the filling materials in root cross-sections from middle root thirds was determined 1, 8, and 30 days after root filling (N = 11 per group). These values were compared between groups using one-way anova (α < 0.05).

Bio-Gutta induced a high pH in the PBS solution, which plateaued at values between 11.4 and 11.8. Apparent CaP crystals covered the Bio-Gutta material after 30 days of immersion in PBS, whilst no such structures were observed on GP. Both materials under investigation had similar initial push-out bond strength values (P > 0.05). The adherence of Bio-Gutta increased from day 1 to 8 and was significantly higher than that of conventional GP at 8 and 30 days (P < 0.05).

The experimental gutta-percha material under investigation was alkaline and caused CaP precipitates on its surface. It improved its adherence to the root canal wall within 1 week.