Objectives: The aim of this prospective longitudinal split-mouth study was to compare the performance of partial ceramic crowns (PCC) inserted with RelyX Unicem either with (RXUSE) or without (RXU) selective enamel etching.
Methods: 43 patients received 86 restorations. In each patient, one PCC was placed with RXU and one PCC with RXUSE. The restorations were clinically rated using modified United States Public Health Service (USPHS) criteria at baseline (BL), 6 and 12 months after placement. Chisquare-tests were performed for statistical analysis.
Results: From the total of 43 patients, 34 patients (male 15, female 19) were available for the three recalls. Median patient age was 41 years (range 24-59). Median (25-75%) PBI was 6% (3-9%). RXU: 25 PCC were placed in molars, 9 in premolars. RXUSE: 26 PCC were placed in molars, 8 in premolars. One PCC (RXU) debonded after 11 months, one PCC (RXUSE) fractured after 12 months in situ. Both restorations were replaced. The evaluation using USPHS criteria revealed that marginal adaptation and marginal discoloration were significantly influenced by the observation periods:
| Time |
| Marginal adaptation | Marginal discoloration | ||||||
Alfa | Bravo | Charlie | Delta | Alfa | Bravo1 | Bravo2 | Charlie | |||
RXU | BL | n % | 33 97.1 | 1 2.9 | 0 0 | 0 0 | 33 97.1 | 0 0 | 1 2.9 | 0 0 |
RXU | 6mo | n % | 29 85.3 | 5 14.7 | 0 0 | 0 0 | 32 94.1 | 2 5.9 | 0 0 | 0 0 |
RXU | 12mo | n % | 17 51.5 | 16 48.5 | 0 0 | 0 0 | 25 75.8 | 8 24.2 | 0 0 | 0 0 |
RXUSE | BL | n % | 34 100 | 0 0 | 0 0 | 0 0 | 33 97.1 | 0 0 | 1 2.9 | 0 0 |
RXUSE | 6 mo | n % | 26 76.5 | 8 23.5 | 0 0 | 0 0 | 29 85.3 | 5 14.7 | 0 0 | 0 0 |
RXUSE | 12mo | n % | 18 52.9 | 16 47.1 | 0 0 | 0 0 | 25 73.5 | 7 20.6 | 2 5.9 | 0 0 |
No statistically significant differences between the different luting techniques were observed during the observation periods.
Conclusion: Within the limitations of the present study, adhesive luting with RelyX Unicem with or without selective enamel etching can be recommended.