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[A clinical analysis of screw-retained implant-supported casted integrated abutment crowns in the molar region with limited interocclusal space].

PURPOSE
To observe the clinical effects of screw-retained implant-supported casted abutment integrated crowns (IACs) in the molar region with limited interocclusal space.


METHODS
This study involved 507 implants in 376 patients with limited interocclusal space in the molar region. All 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 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 with 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.


CONCLUSIONS
Screw-retained IACs can be used to repair missing teeth in the molar region with limited interocclusal space.