Fracture strength of adhesively restored pulpotomized primary molars

To evaluate the cuspal fracture resistance of primary teeth restored with different adhesive techniques.

Eighty primary molars were selected for pulpotomy preparations. The molars were matched according to molar type (upper or lower, 1st or 2nd), and divided into four groups: Group 1: Pulpotomy cavity restored with IRM, Dispersalloy amalgam (Control); Group 2: IRM, Hydroxyline, Amalgambond Plus and Dispersalloy; Group 3: IRM, Hydroxyline, Prime & Bond 2.1 and Dyract; Group 4: IRM, Hydroxyline, Single Bond and Z100 resin composite. In Groups 2,3 & 4, Hydroxyline was placed over the IRM to avoid direct contact of the adhesives and resin with the IRM. All specimens were thermocycled (1000 cycles, 5-55 degrees C), and mounted in acrylic 2 mm apical to the CEJ. The molars were then tested for cuspal fracture strength using an Instron machine with tapered steel balls made to match the occlusal area of the primary molars tested. Repeated measures ANOVA and paired t-test were used to test the statistical significance of the results.

Mean fracture loads in Newtons + S.D.) were as follows: G1: 1087 + 284; G2: 1371 + 434; G3: 1336 + 320; G4: 1404 + 312. The three bonded procedures significantly (P < 0.001) increased the resistance of the primary molars to fracture compared to the control group. There was no significant difference between the three bonded procedures.

Bonded restorations of pulpotomized primary molars may be an alternative restorative procedure to stainless steel crowns.