The Survival Rate of Glass Ionomer Cement, Glass Carbomer Cement and Compomer in Occlusal and Proximal ART Restorations

The null hypothesis of this study is that GCC, GIC and compomer have the same survival rate when used for the treatment of occlusal and proximal caries in primary molars with ART under field conditions.

This research will be done under field conditions in Barueri, a city in the state of São Paulo, Brazil. A total of 600 patients will be selected, 300 patients with one occlusal carie lesion and 300 different patients with occlusal proximal cavities. After 1, 6, 12, 18 and 24 months the restorations and teeth will be evaluated by two independent evaluators. Only children whose parent or representative who have signed an informed consent are included in this research. Only one restoration per child will be included in this study. If more carious lesions are present, one of them will be randomly selected for this research. The remaining carious lesions will be also be treated. The ART treatments will be done by two dental students. The operators will receive the same ART-training.

The children will be randomly assigned to one of the operators. The restorative material to be used in each child will be assigned by another random list.

The selected children can have or an occlusal (O) cavity or an occlusalproximal (OP) cavity. So, the stratum of the study is OP and O. So, one randomization list will be performed for occlusal cavities and another randomization list will be used for occlusal proximal cavities.

It will be performed descriptive analyses to describe the sample. Bivariate analyses will be performed to test the hypothesis. The data will be analyzed with a chi-square test to compare the survival rates of GIC and GCC. Some co-variables will be evaluated, such as: operator effect, the influence of the cavity size on the survival rate, the position of the tooth, the dentists preferred side, the child's dmft/DMFT, contamination and finally the preoperative conditions. The effect of these variables on the survival rate will be evaluated using a regression analysis.

Inclusion criteria

Inclusion criteria

for the patient:

• Healthy children, age: 4-8 years
• At least one occlusal or proximal carious lesion in primary molar involving dentin
• Cooperative behavior
• Presence of antagonist of the tooth

Inclusion criteria

for the tooth:

• Carious lesion involving dentin with dimensions bucco-lingual and mesio-distal not greater than 2.5mm, occluso-cervical not greater than 2.0mm
• Absence of tooth mobility and abscess or fistula near to the selected tooth

Exclusion criteria

• Only children whose parent or representative who have signed an informed consent are included in this research. Only one restoration per child will be included in this study. If more carious lesions are present, one of them will be randomly selected for this research.