Purpose of the Study:This study was to evaluate the 1 week, 1 year safety and effectiveness of dental composite resin (Filtek™ Bulk Fill Posterior Restorative) in restoring Class I and II dental cavities in posterior teeth.

This was a randomized, two- arm, non-inferiority study to evaluate the safety and clinical performance of resin composite, Filtek™ Bulk Fill.

Test apparatus: Apparatus for Test: Filtek™ Bulk Fill Posterior Restorative Apparatus for Control: 3M™ ESPE™ Filtek™ Z350XT, was approved by CFDA in 2010 and had been in the market for 5 years with some validated clinical data.

Sample Size of Subjects: Two-hundred forty (240) patients were expected to be recruited into the study and were randomly assigned to the test group and the control group according to the ratio of 1: 1; thus the number of cases in each group was 120. Finally, a total of 240 subjects were randomly enrolled in the study, including 120 subjects in the test group and 120 subjects in the control group, which met the required sample size.

The study consisted of screening period (initial screening visit, post-preparation screening visit), 1-week follow-up visit and 1-year follow-up visit, during which all the tests required in the protocol would be conducted to select the subjects meeting the criteria for inclusion. The examination and evaluation of the initial screening period were supposed to be completed within 0.5 days. Then investigators would make an appointment with the subjects eligible for the initial screening for cavity preparation and tooth filling, the required time of which depended on the complexity of the tooth problem and would be completed within 0.5 days. Immediate evaluation of relevant indicators were offered to the subjects who were selected and qualified after preparation and patients with qualified score would continue to have the 1-week and 1-year follow-up visits.

Subjects were randomly assigned to either the test group (Filtek™ Bulk Fill Posterior Repository) or the control group (Filtek™ Z350XT) in a central random manner, using the corresponding test product or control product to fill and restore posterior teeth defects (class I or class II cavities).

Since all investigators were required to operate according to instructions, it was clear to them which product a subject was given. However, subjects and clinical evaluators were blinded regarding whether the test product (Filtek™ Bulk Fill Posterior Repository) or the control product (Filtek™ Z350XT) was used by the subjects.

Immediately after restoration placement, at 1 week and 1 year postoperative, two or three clinical evaluators from each site performed the clinical assessment (the third more senior evaluator performed the assessment and determination if the first two evaluators were not in agreement) per China Technical Instruction and Guidance of Resin Composite Restoration Material For CFDA Registration (Technical Instruction and Guidance in short). The clinical acceptable rate of the restoration at 1 year was the primary endpoint in this study.

AE/SAE were collected to evaluate the safety of Filtek™ Bulk Fill. Based on the assessment result, if the clinical acceptance rate of the two groups achieved the clinical acceptable rate defined in the protocol, it indicated that Filtek™ Bulk Fill was efficacious for class 1 and II restorations.

Inclusion Criteria:

1. Male or female,18 to 70 years old (including 18 and 70 years)
2. Good health, no significant systemic disease;
3. Normal opening degree;
4. Molar (preferred) or premolar teeth
5. Cavity type with belongs to any of the following： 1) Class I, including the failed class I restoration which require to be repaired.; 2) Class II, including premolar and molar except the second molar (the failed class II restoration which require to be repaired is also included), and the gingival wall of cavity is above the free gingival margin coronally; 3) Class II cavity on the second molar when the third molar exists, and the gingival wall of cavity is above the free gingival margin coronally; 4) Class II, MO or MOD cavity on the second molar when the third molar does not exist (the failed class II restoration which require to be repaired is also included), and the gingival wall of cavity is above the free gingival margin coronally;
6. Cavity size: the buccolingual diameter of cavity is no less than the 1/3 and of the buccolingual cusp distance;
7. Occlusion with natural teeth;
8. Cavity depth: no less than 1/2 of dentin with a normal pulp status;
9. Be able to understand informed consent and to provide written inform consent ;
10. Be in good compliance with the protocol and willing to return to the site for follow up visits .

Exclusion Criteria:

1. Allergy to multiple medicines; allergy to resin or other polymer material;
2. Acute caries, severe periodontitis, salivary glands malfunction, dysfunction/disorder of TMJ (temporomandibular joint);
3. Poor oral hygiene, DMTF:18-34y >4, 35-70y >5;
4. Teeth with abnormal staining ;
5. Pathological abrasion (e.g. bruxism, clenching), acid corrosion, cracked-teeth and other non-caries diseases.
6. Abnormal occlusion;
7. Severe systemic or mental disorders;
8. Pregnant or intended to be pregnant (pregnant test is positive ) or breast feeding women;
9. Cavity do not meet the criteria based on the investigator's judgement;
10. Resin Composite is not an appropriate restoration for the subject
11. Pulp exposure or bottom of cavity is nearly close to the pulp;
12. Subjects who is not able to return for the one year follow-up visit because of going abroad or other reasons;
13. Subject is enrolled in other studies on investigational drug or device
14. Cannot tolerate rubber dam isolation. -

Adverse Events (AEs) and Serious Adverse Events (SAEs) were collected from enrollment through study completion, an average of 1 year per participant.