Table 1.
Specifications of the tested implant systems, abutment screws, implant abutments, and mean value ± standard deviation of IRT (Ncm), PRT (Ncm), and TLR (%) in each group.
| System | Dimensions of implants (mm) | Screw | Initial removal torque (Ncm) | Difference of initial removal torque (%) | Postloading removal torque (Ncm) | Difference of postloading removal torque (%) | Removal torque loss (Ncm) | Removal torque loss rate (%) | Difference of removal torque loss rate (%) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | (A − C)/C | (B − C)/C | A | B | C | (A−C)/C | (B−C)/C | A | B | C | A | B | C | (C−A) | (C−B) | |||
| Nobel | Ø3.5 × 11.5 | NP | 29.70 ± 0.47Aa | 29.78 ± 0.66Aa | 27.58 ± 0.54Ab | 7.69% | 7.99% | 20.62 ± 0.47Aa | 20.58 ± 0.79Aa | 17.54 ± 0.85Ab | 17.56% | 17.33% | 9.08 ± 0.65Aa | 9.20 ± 0.54Aab | 10.04 ± 0.47Ab | 30.56 ± 1.89Aa | 30.90 ± 1.84Aa | 36.42 ± 2.07Ab | 5.86% | 5.52% |
| Ø4.3 × 11.5 | RP | 28.42 ± 0.55Ba | 28.56 ± 0.40Ba | 26.42 ± 0.72Bb | 7.57% | 8.10% | 17.90 ± 0.29Ba | 18.00 ± 0.43Ba | 15.38 ± 0.63Bb | 16.38% | 17.04% | 10.48 ± 0.48Ba | 10.56 ± 0.15ABa | 11.04 ± 0.15ABa | 37.01 ± 0.90Ba | 36.98 ± 0.75Ba | 41.80 ± 0.86Bb | 4.79% | 4.82% | |
| Ø5.0 × 11.5 | RP | 32.68 ± 0.48Ca | 32.48 ± 0.56Ca | 30.56 ± 0.69Cb | 6.94% | 6.28% | 21.36 ± 0.54Aa | 21.22 ± 0.61Aa | 18.60 ± 0.85Ab | 14.84% | 14.09% | 11.32 ± 0.26Ca | 11.26 ± 0.23Ba | 11.96 ± 0.17Bb | 34.64 ± 0.93Ca | 34.68 ± 0.94Ca | 39.16 ± 1.40Cb | 4.52% | 4.48% | |
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| Straumann | Ø3.3 × 12.0 | NC | 30.00 ± 0.57Aa | 29.82 ± 0.48Aa | 27.72 ± 0.70Ab | 8.23% | 7.58% | 24.28 ± 0.29Aa | 24.12 ± 0.48Aa | 21.58 ± 0.67Ab | 12.51% | 11.77% | 5.72 ± 0.57Aa | 5.70 ± 0.48Aa | 6.14 ± 0.37Aa | 19.05 ± 1.61Aa | 19.11 ± 1.51Aa | 22.15 ± 1.28Ab | 3.10% | 3.04% |
| Ø4.1 × 12.0 | RC | 31.92 ± 0.33Ba | 32.04 ± 0.36Ba | 29.70 ± 0.66Bb | 7.47% | 7.88% | 27.20 ± 0.38Ba | 27.22 ± 0.32Ba | 24.18 ± 0.68Bb | 12.49% | 12.57% | 4.72 ± 0.16ABa | 4.82 ± 0.28Ba | 5.52 ± 0.22ABb | 14.79 ± 0.55Ba | 15.04 ± 0.79Ba | 18.59 ± 0.81Bb | 3.80% | 3.55% | |
| Ø4.8 × 12.0 | RC | 34.12 ± 0.36Ca | 33.96 ± 0.29Ca | 31.62 ± 0.52Cb | 7.91% | 7.40% | 29.86 ± 0.65Ca | 29.60 ± 0.36Ca | 26.38 ± 0.59Cb | 13.19% | 12.21% | 4.26 ± 0.30Ba | 4.36 ± 0.34Ba | 5.24 ± 0.11Bb | 12.49 ± 0.99Ca | 12.84 ± 0.96Ca | 16.58 ± 0.56Cb | 4.09% | 3.74% | |
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| WEGO | Ø3.4 × 11.0 | NP | 11.92 ± 1.04Aa | 11.64 ± 0.57Aa | 10.30 ± 0.41Ab | 15.73% | 13.01% | 4.08 ± 0.77Aa | 4.04 ± 0.40Aa | 2.98 ± 0.26Ab | 36.91% | 35.57% | 7.84 ± 0.71Aa | 7.60 ± 0.23Aa | 7.32 ± 0.20ABa | 65.88 ± 4.83Aa | 65.35 ± 1.95Aa | 71.10 ± 1.58Aa | 5.22% | 5.75% |
| Ø3.8 × 11.0 | RP | 14.76 ± 0.40Ba | 14.08 ± 1.30Ba | 12.14 ± 0.82Bb | 21.58% | 15.98% | 6.78 ± 0.61Ba | 6.52 ± 0.98Ba | 4.68 ± 0.80ABb | 44.87% | 39.32% | 7.98 ± 0.49Aa | 7.56 ± 0.38Aa | 7.46 ± 0.38Aa | 54.09 ± 3.56ABa | 53.89 ± 2.83Ba | 61.63 ± 4.66ABb | 7.54% | 7.74% | |
| Ø4.3 × 11.0 | RP | 15.68 ± 0.76BCa | 15.46 ± 0.93BCa | 13.90 ± 0.78Cb | 12.81% | 11.22% | 8.98 ± 0.91Ca | 8.74 ± 0.90Ca | 6.92 ± 0.79BCb | 29.77% | 26.30% | 6.70 ± 0.28Ba | 6.72 ± 0.49ABa | 6.98 ± 0.19Ba | 42.84 ± 3.26Ba | 43.54 ± 3.26Ca | 50.34 ± 2.98BCb | 7.50% | 6.80% | |
| Ø5.0 × 11.0 | RP | 16.82 ± 0.62Ca | 16.38 ± 0.90Ca | 15.18 ± 0.52Db | 10.80% | 7.91% | 10.72 ± 0.93Da | 10.46 ± 0.91Da | 8.68 ± 0.61Cb | 23.50% | 20.51% | 6.10 ± 0.41Ba | 5.92 ± 0.58Ba | 6.50 ± 0.12Ca | 36.35 ± 3.49Ba | 36.18 ± 3.34Da | 42.87 ± 2.11Cb | 6.52% | 6.69% | |
Within the same column, mean values followed by the same capital letter are statistically similar (P > 0.05), whereas mean values followed by different capital letters are statistically different (P < 0.05) among different-diameter implants using the same tightening method. Within the same row, mean values followed by the same lowercase letter are statistically similar (P > 0.05), whereas mean values followed by different lowercase letters are statistically different (P < 0.05) among same-diameter implants using different tightening methods.