Increased infection rates of sinus floor elevations after the use of a bone filter

Modified Le Fort I interpositional grafting of the severe atrophied maxilla - a retrospective study of 106 patients over 10 years

OBJECTIVES

The objective of this study was to evaluate a modified Le Fort I interpositional grafting followed by dental implants for the rehabilitation of edentulous atrophied maxillae (Cawood classes IV and V). The surgical modification was a bilateral sinus floor augmentation prior to the osteotomy. This generated a closed recipient bed which allowed the use of particulated bone grafts (xenogenic bone mineral) and a reduced amount of autologous iliac bone grafts.

MATERIALS AND METHODS

106 patients with maxillary interpositional bone grafts were included in this retrospective analysis between 2006 and 2020. The panoramic radiographs and lateral cephalograms were analysed to assess the gain and stability of the maxillary bone and the peri-implant bone loss. In addition, the observational period of up to 14 years implant survival and success was evaluated.

RESULTS

A stable vertical bone height with mean 0.63 ± 1.41mm resorption over 5 years after implant loading was observed. A mean of 0.20 ± 0.37mm marginal bone loss was noted after 5 years. The implant survival was 96.4% after 5 years and implant success can be rated 91.7% in a mean follow-up period of 93 months and 168 months maximal observation time. Perioperative complications included sinus membrane perforation (59.43%), wound healing disturbances (25.47%) and transient primary complications (13.78%). All receded apart from two subtotal graft losses (1.8%).

CONCLUSIONS

The modified Le Fort I osteotomy with interpositional bone grafts is a predictable procedure in terms of bone and implant stability. Patients with atrophic maxillae who are fit for surgery should be informed about risks and benefits of this treatment alternative.

A three-dimensional-printed SPION/PLGA scaffold for enhanced palate-bone regeneration and concurrent alteration of the oral microbiota in rats

Scaffold implantation for the repair of oral bone defects involves an interplay between the scaffold biomaterial and the microenvironment. However, previous studies on this subject have only considered the effects of the immune system and largely ignored those of the oral microbiota. Accordingly, in the present study, we prepared composite scaffolds comprising a three-dimensional poly(l-lactide-co-glycolide) matrix with a superparamagnetic iron oxide nanoparticle (SPION) coating and used a rat model to evaluate their palate-bone-regenerating effects and their interaction with the oral microbiota. It was found that the SPION coated scaffold induced better bone regeneration than that achieved by the controls. Furthermore, it significantly decreased the operational taxonomic units (OTU) numbers as determined by 16 s rRNA gene sequencing, and also resulted in decreased Chao and ACE alpha diversity indexes compared with those of the controls. However, it had no effect on beta diversity. SPION coated scaffolds caused a shift in oral bacterial composition characterized by a decrease in the Clostridium spp. population, and the dominant flora being Proteobacteria. Furthermore, SPION coated scaffolds upregulated the concentration of serum iron, hepcidin, and P1NP. Thus, SPION coated scaffolds enhanced bone regeneration, and this effect was partly related to alteration of the oral microbiota by the antibacterial effects of SPION. Our findings provide a better understanding of the role of oral microbiota in oral bone regeneration and how SPION coated scaffolds can be used to enhance it.