Periapical endodontic surgery may be indicated when orthograde retreatment of failed endodontic therapy is unsuccessful, unfeasible or contraindicated. The sequence of procedures during the surgery includes exposure of the involved apex, root-end resection, root-end cavity preparation and placement of a root-end filling. The root-end filling is necessary in order to provide a hermetic seal, thereby preventing the egress of micro-organisms into the periradicular tissues from the root canal system.
The purpose of this in-vitro study was to compare the microleakage of three calcium silicate cements and amalgam when used as retrograde filling materials.
One hundred and twenty single rooted, single canal, human teeth with closed apices were collected and stored in Phosphate Buffered Saline after extraction. All root canals were instrumented using ProTaper rotary instruments and obturated by warm vertical condensation using gutta-percha with Topseal Root Canal Sealer. Access cavities were sealed with Fuji IX glass ionomer restorative material.
The apical 3mm of each root was resected perpendicular to the long axis of the root and root-end cavities were prepared to a depth of 3mm using ProUltra surgical ultrasonic tips. The teeth were randomly divided into four groups (n=30):
Group 1 - ProRoot MTA (Dentsply/Maillefer)
Group 2 - MTA PlusTM (Prevest Denpro Limited)
Group 3 – BiodentineTM (Septodont)
Group 4 – Permite Amalgam (SDI)
The materials were manipulated according to the manufacturer’s instructions and used to fill the root-end cavities. The specimens were then coated with two layers of clear varnish, except the resected apical surface.
Teeth were stored in gauze, moistened with Phosphate Buffered Saline for 24 hours and thereafter submerged in Indian Ink dye for 48 hours. The excess dye was rinsed off the specimens under running water. Specimens were then sectioned horizontally in one millimetre increments from the apical end of the root. The extent of dye penetration was measured to the nearest millimetre using a stereomicroscope.
Data for different groups was collected and summarised in terms of percentage for the outcome vector (no leak, 1 mm leak, 2 mm leak and 3 mm leak). Furthermore pairwise comparisons between each of the calcium silicate materials to amalgam were done at the 0.017 level of significance, using Fisher’s exact test.
Amalgam showed significantly more leakage than the calcium silicate materials (p<0.001). No significant differences were found among the calcium silicate materials, namely, BiodentineTM vs ProRoot (p=0.776), BiodentineTM vs MTA PlusTM (p=0.667) and ProRoot vs MTA PlusTM (p= 0.350).
Dissertation (MScDent)--University of Pretoria, 2015.