The reduction of vertical food impact using adjacent surface retaining zirconium crowns preparation technique: a 1-year follow-up prospective clinical study

BACKGROUND: Our study aims to investigate the clinical effect of adjacent surface retaining zirconium crowns preparation technique in the restoration of molar defects. METHODS: For the adjacent contact preservation method, molars were repaired by the adjacent open partial crown (treatment group). In the control group, molars were prepared using the traditional full-crown preparation method. All the subjects were followed-up for 12 months. The data analysis was conducted by using SPSS17.0 software. Then, the chi-square test was used to analyze the statistical difference. P<0.05 was considered statistically significant. RESULTS: After a one-year observation, there was no secondary caries had been detected among the total 80 adjacent surfaces (46 molars). Only one case with food impact was found in the treatment group (48 surfaces), and 5 cases were found in the control group. The incidence rate was 2.08% and 15.62%, respectively. There was a statistically significant difference between the two groups. CONCLUSIONS: Compare to the traditional tooth preparation method, keep adjacent areas of the tooth to reserve a space for partial zirconium crowns, would significantly reduce the food impact for a 1-year follow-up. Thus, this adjacent surface retaining zirconium crowns preparation technique is efficiently conducted in clinical practice and the short-term clinical effect is good.