Table 3.
Factors associated with Goodness of fit (GOF) of crowns. Crown fit was documented by the study dentist at the cementation visit and correlated with laboratory technician ratings of various impression and preparation parameters. Significant p values indicate the factor was associated with clinical fit of the crown
| Parameter evaluated by laboratory technician while the case was in the laboratory | Goodness of fit as determined by study dentist at cementation visit (N and row percentage) | Total* (N and column percentage) | p Value | |
|---|---|---|---|---|
| Excellent or good | Acceptable | |||
| Impressions | ||||
| Completeness of the Margin Represented in the Impression | ||||
| Excellent (100% reproduced) | 1126 (86) | 177 (14) | 1303 (39) | 0.32 |
| Good (95% of margin visible) | 1487 (87) | 232 (13) | 1719 (52) | |
| Fair (significant areas missing) | 217 (83) | 44 (17) | 261 (8) | |
| Poor (marginal detail mostly missing) | 20 (87) | 2 (13) | 23 (1) | |
| Quality of the Impression other than the Margin Detail | ||||
| Excellent | 925 (87) | 141 (13) | 1066 (32) | 0.03 |
| Good | 1607 (86) | 256 (14) | 1863 (56) | |
| Fair | 289 (84) | 54 (16) | 343 (11) | |
| Poor | 28 (82) | 6 (18) | 34(1) | |
| Are There Signs of Distortion in the Impression? | ||||
| Yes | 1093 (88) | 147 (12) | 1240 (38) | 0.22 |
| No | 1757 (85) | 310 (15) | 2067 (63) | |
| Preparations | ||||
| Technician’s Evaluation of the Axial Reduction | ||||
| Excessive | 187 (92) | 16 (8) | 203 (6) | 0.54 |
| Adequate | 2589 (86) | 426 (14) | 3015 (91) | |
| Insufficient | 75 (83) | 15 (17) | 90 (3) | |
| Technician’s Evaluation of the Occlusal Reduction | ||||
| Excessive | 289 (93) | 22 (7) | 311 (9) | 0.04 |
| Adequate | 2431 (86) | 399 (14) | 2,830 (86) | |
| Insufficient | 131 (78) | 36 (22) | 167 (5) | |
| Technician’s Evaluation of the Taper | ||||
| Excessive | 185 (95) | 10(5) | 195 (6) | 0.005 |
| Adequate | 2597 (86) | 423 (14) | 3020 (91) | |
| Insufficient | 71 (75) | 23 (24) | 94 (3) | |
| Technician’s Evaluation of the Finish & Smoothness of the Preparation and Margin | ||||
| Excellent | 810 (87) | 119 (13) | 929 (28) | 0.71 |
| Good | 1696 (87) | 258 (13) | 1954 (59) | |
| Fair | 328 (81) | 77 (19) | 405 (12) | |
| Poor | 20 (87) | 3 (13) | 23 (1) | |
| Other Items | ||||
| Technician’s Evaluation of the Quality of the Opposing Cast | ||||
| Excellent | 813 (86) | 135 (14) | 948 (29) | 0.93 |
| Good | 1742 (86) | 273 (14) | 2015 (61) | |
| Fair | 224 (85) | 41 (15) | 265 (8) | |
| Poor | 64 (90) | 7 (10) | 71 (2) | |
| How Opposing was Made (not dual arch) | ||||
| PVS Impression | 120 (79) | 32 (21) | 152 (5) | 0.03 |
| Stone Cast | 176 (87) | 27 (13) | 203 (6) | |
| Optical Impression | 462 (95) | 26 (5) | 488 (15) | |
| Technician’s Evaluation of the Quality of the Centric Record | ||||
| Good | 2355 (87) | 361 (13) | 2716 (83) | 0.22 |
| Fair | 371 (82) | 82 (18) | 453 (14) | |
| Poor | 93 (92) | 8 (8) | 101 (2) | |
| Type of Centric Record | ||||
| Hand Articulated | 337 (85) | 60 (15) | 397 (12) | 0.04 |
| Optical | 462 (95) | 26 (5) | 488 (15) | |
| PVS Record | 424 (86) | 71 (14) | 495 (15) | |
| Dual Arch Tray | 1604 (85) | 294 (15) | 1899 (56) | |
| Shade Information | ||||
| Simple (single shade given) | 72 (92) | 6(8) | 78 (2) | 0.09 |
| Moderate (2–3 shades over areas of tooth) | 266 (90) | 30 (10) | 296 (9) | |
| Detailed (shade map, photographs) | 2471 (86) | 413 (14) | 2884 (89) | |
| Crown Fabrication Technique Used by Laboratory to Make Crown | ||||
| Milled by CAD/CAM | 1556 (87) | 238(13) | 1794 (54) | 0.85 |
| Mostly by machine, with additions by the laboratory technician | 438 (89) | 56(11) | 494 (15) | |
| Mostly made by the laboratory technician | 859 (84) | 163 (16) | 1022 (31) | |
*
Due to missing values and rounding, not all columns sum to 100 percent, and totals may differ among input variables. Missing data values are reported in Table 1.