PMID- 37099583 OWN - Quintessenz Verlags-GmbH CI - Copyright Quintessenz Verlags-GmbH OCI - Copyright Quintessenz Verlags-GmbH TA - Int J Oral Maxillofac Implants JT - The International Journal of Oral & Maxillofacial Implants IS - 1942-4434 (Electronic) IS - 0882-2786 (Print) IP - 1 VI - 38 PST - ppublish DP - 2023 PG - 94-100 LA - en TI - Effect of Abutment Cooling on Reverse Torque Values of Abutment Screws: An In Vitro Study LID - 10.11607/jomi.9499 [doi] FAU - Srimurugan-Thayanithi, Nirosa AU - Srimurugan-Thayanithi N FAU - Abou-Ayash, Samir AU - Abou-Ayash S FAU - Yilmaz, Burak AU - Yilmaz B FAU - Schimmel, Martin AU - Schimmel M FAU - Brägger, Urs AU - Brägger U CN - OT - abutment screw OT - blocked implants OT - cryo-mechanical OT - maintenance OT - technical complications AB - Purpose: To evaluate the effect of cooling on the reverse torque values of different abutments in bone-level and tissue-level implants. The null hypothesis was that there would be no difference in reverse torque values of abutment screws when cooled and uncooled implant abutments were compared. Materials and Methods: Bone-level and tissue-level implants (Straumann, each n = 36) were placed in synthetic bone blocks and subdivided into three groups (each n = 12) based on the abutment type (titanium base, cementable abutment, abutment for screw-retained restorations). All abutment screws were tightened to 35 Ncm torque. In half of the implants, a dry ice rod was applied on the abutments close to the implant-abutment connection for 60 seconds before untightening the abutment screw. The remaining implant-abutment pairs were not cooled. The maximum reverse torque values were recorded using a digital torque meter. The tightening and untightening procedure was repeated three times for each implant including cooling for the test groups, resulting in 18 reverse torque values per group. Two-way analysis of variance (ANOVA) was used to analyze the effect of cooling and abutment type on the measurements. Post hoc t tests were used to make group comparisons (α = .05). The P values of post hoc tests were corrected for multiple testing using the Bonferroni-Holm method. Results: The null hypothesis was rejected. Cooling and abutment type significantly affected the reverse torque values in bone-level implants (P = .004) but not in tissue-level implants (P = .051). The reverse torque values of bone-level implants significantly decreased after cooling (20.31 ± 2.55 Ncm vs 17.61 ± 2.49 Ncm). Overall mean reverse torque values were significantly higher in bonelevel implants compared to tissue-level implants (18.96 ± 2.84 Ncm vs 16.13 ± 3.17 Ncm; P < .001). Conclusion: Cooling of the implant abutment led to a significant decrease in reverse torque values in bone-level implants and may therefore be recommended as a pretreatment before the application of procedures to remove a stuck implant part. Int J Oral Maxillofac Implants 2023;38:94–100. doi: 10.11607/jomi.9499 AID - 3929753