A Clinical Analysis Of Screw-retained Implant-supported Casted Integrated Abutment Crowns In The Molar Region With Limited Interocclusalspace

PURPOSE:To observe the clinical effects of screw-retainedimplant-supported casted abutment integrated crowns(IACs)in the molar region with limitedinterocclusal space and give guidance to clinicians.METHODS:This study involved 507 implants in 376 patients with limited interocclusal space in the molar region.All the implants were inserted to the jaw by standard one-stage protocol.Screw-retained IACs were used as the final prosthesis.With 6 to 24 months follow-up,the clinical effects of screw-retained IACs were recorded and analyzed using SPSS 17.0 software package.RESULTS:During the 6 to 24 months of follow-up,the implant survival rate was 99.61%.37 patients had ceramic fracture which mainly happened in the group of 3～4 mm interocclusal space.In each group,porcelain fused to metal(PFM)prosthesis had ceramic fracture more easily than PFM prosthesis without porcelain on occlusal surface(P<0.05).As the interocclusal space became smaller,the probability of collapsing porcelain increased(P<0.05).13 patients had screw loosening.13 patients suffered from gingival swelling and bleeding,they were given periodontal treatment and oral hygiene instruction.Patients were satisfied with the restoration results.CONCLUSION:1 The effect of screw-retained IACs was stable and gotten patients approval in the short term.2 There was no peri-implantitis,maybe benefited from the design of screw-retained IACs.3 The incidence of mechanical complications in the design of the occlusal without porcelain was lower in the short term.4 It was recommended to use all metal crown,when the interocclusal space was seriously insufficient in the molar region.5 Screw-retained IACs can be used to repair the missing teeth in the molar region with limited interocclusal space and worthy of promotion.