Table 3.
Percentage* and number of crowns that were bonded or not, overall and by crown or preparation characteristic
| Crown or preparation characteristic | N*** | Bonded crowns, % (n) | Non-bonded crowns, % (n) | Comparisons |
|---|---|---|---|---|
| Overall | 3468 | 38.1 (1321) | 61.9 (2147) | -- |
| Preparation taper** | p = .15 | |||
| Excessive | 194 | 62.9 (122) | 37.1 (72) | |
| Adequate | 2924 | 35.0 (1025) | 65.0 (1899) | |
| Insufficient | 92 | 32.6 (30) | 67.4 (62) | |
| Occlusal reduction** | p = .02 | |||
| Excessive | 310 | 75.8 (235) | 24.2 (75) | a |
| Adequate | 2734 | 33.0 (901) | 67.0 (1833) | b |
| Insufficient | 165 | 24.2 (40) | 75.8 (125) | b |
| Axial reduction** | p = .08 | |||
| Excessive | 202 | 67.3 (136) | 32.7 (66) | |
| Adequate | 2920 | 34.5 (1008) | 65.5 (1912) | |
| Insufficient | 87 | 37.9 (33) | 62.1 (54) | |
| Restorative material | p < .01 | |||
| Leucite-reinforced | 17 | 76.5 (13) | 23.5 (4) | a |
| Lithium disiliciate | 1012 | 70.9 (717) | 29.1 (295) | a |
| Layered zirconia | 268 | 33.8 (104) | 61.2 (164) | b |
| Full contour zirconia | 1131 | 30.1 (340) | 69.9 (791) | b |
| Full metal | 177 | 14.7 (26) | 85.3 (151) | c |
| PFM | 857 | 13.8 (118) | 86.2 (738) | c |
| Other | 2 | 100 (2) | 0 (0) | --- |
| Location in arch | p < .01 | |||
| Anterior maxilla | 228 | 43.0 (98) | 57.0 (130) | a |
| Posterior maxilla | 1609 | 37.6 (605) | 62.4 (1004) | b |
| Anterior mandible | 39 | 41.0 (16) | 59.0 (23) | a,b |
| Posterior mandible | 1585 | 37.8 (599) | 62.2 (986) | b |
| Crown margin location | p = .35 | |||
| At or above | 1432 | 39.9 (572) | 60.1(860) | |
| gingival crest | ||||
| 1 mm below gingival crest | 1344 | 40.4 (543) | 59.6 (801) | |
| 2 mm or more below gingival crest | 688 | 29.7 (204) | 70.35 (484) |
*
Raw percentages are presented. P-values reflect adjustment for clustering within clinician, using mixed-model logistic regression. Categories with the same letter are not significantly different.
**
Based on assessment of the crown impression by the laboratory technician who made the prosthetic crown.
***
N = Numbers of crowns in row category. Total sample sizes vary due to the presence of missing values for some characteristics.