Seventy class II composite resin restorations in primary molars were clinically evaluated at the baseline,6-month recall, and 12-month recall visits, using the modified Ryge criteria and bite-wing radiographs. The clinical procedures included cavity preparation with a round bevel on the occlusal margin, the use of hydrophilic bonding agent of P-50 (3 M) or Palfique Light Posterior (TOKUYAMA)system, and the application of glass ionomer lining cement on the gingival wall.
The results up to one year were as follows;
1) In the 12-month follow-up, there was no difference in clinical performance among the composite materials, and there was found no loss of the restoration, marginal discoloration, color change, postoperative pain, pulp irritation, and secondary caries.
2) The results for proximal adaptation, wear, and surface roughness were satisfactory.
3) Although 17 cases (9 sites) had loose contact at the baseline evaluation, all had recovered by the 6-month recall.
4) Body fracture of the composite resin was found in 3 cases in 6 months, and in a further 3 cases between the 6- and 12-month recalls, of which 4 cases were retreated.
5) Early marginal microfracture should be noted since slightly poor marginal adaptation was found in 15 cases in 6 months, and in a further 9 cases between 6 and 12 months. However, by polishing the marginal step,10 out of 15 cases at the 6-month recall were found to maintain good marginal adaptation at the 12-month recall.