Resumen de Straight and tilted implants for supporting screw-retained full-arch dental prostheses in atrophic maxillae: a 2-year prospective study
M. Menéndez Collar, María Angeles Serrera Figallo, Pilar Hita Iglesias, Raquel Castillo de Oyagüe, Juan Carlos Casar Espinosa, Aida Gutiérrez Corrales, José Luis Gutiérrez Pérez, Daniel Torres Lagares
To evaluate, over a 2-year period, the treatment outcomes for maxillary full-arch fixed dental prostheses (FDPs) supported by a combination of both tilted and axially-placed implants and to compare the marginal bone loss (MBL) and implant survival rates (SR) between tilted and axial implants.
A retrospective study has been carried out. Thirty-two patients (16 males and 16 females) treated with maxillary full-arch FDPs were included in this retrospective study. A total of 187 implants were inserted to rehabilitate the fully edentulous maxillary arches: 36% of them were tilted (T group, n = 68) and the remaining 64% were axially placed (A group, n = 119). From the total, 28% of the implants (n=53) were immediately loaded with screw-retained provisional acrylic restorations, whereas 72% underwent conventional delayed prosthetic loading 6 months post-operatively. Definitive restorations were hybrid implant prostheses (metal framework covered with high-density acrylic resin) and metal-ceramic screw-retained implant prostheses, and were placed 6 months after surgery. Such definitive restorations were checked for proper function and aesthetics every three months for two years. Peri-implant marginal bone levels were assessed by digital radiographs immediately after surgery and MBL was assessed at definitive implant loading (baseline) and 2 years afterwards.
The 2-year implant SR were 100% for axially placed implants and 98.5% for tilted implants. No significant differences were found amongst the A and T implant groups. Marginal bone loss measured at 2 years after definitive prosthetic loading was of -0.73 ± 0.72 mm (maximum MBL of 1.43 mm) for axially positioned implants vs. –0.51 ± 0.92 mm for tilted implants (maximum bone 1.45 mm). Differences in MBL were statistically significant when comparing immediately and delayed loaded implants.
Based on the results of this retrospective clinical study, full-arch fixed prostheses supported by a combination of both tilted and axially placed implants may be considered a predictable and viable treatment modality for the prosthetic rehabilitation of the completely edentulous maxilla.
