Bone Regeneration After Sinus Floor Elevation in an Intact Sinus or a Sinus With Prior Large Membrane Perforation: A Preclinical Study Using a Rabbit Sinus Model

Abstract

<bold>Aim: </bold>To determine bone regeneration following sinus floor elevation (SFE) at sites with or without prior sinus membrane perforation. <bold>Materials and methods: </bold>The sinus membranes in the maxillary sinuses of 12 rabbits were intentionally perforated (>= 5 mm) on one side, followed by application of a collagen matrix. SFE was performed on both sinuses after 8 weeks of healing, presenting two groups: SFE with a previous large sinus membrane perforation (group SFE_Perf), and in an intact sinus (group SFE). The animals were euthanized at 2 and 4 weeks after SFE. Micro-computed tomographic and histomorphometric analyses were performed. <bold>Results: </bold>The amount of newly formed bone within the augmented area did not differ significantly between the two groups at 2 weeks and 4 weeks (4.7 +/- 1.0 mm(2) vs. 5.3 +/- 1.4 mm(2) and 9.2 +/- 1.7 mm(2) vs. 10.8 +/- 2.2 mm(2), respectively, mean +/- SD; p > 0.05). However, the amount of newly formed bone near the middle of the sinus membranes was significantly greater in group SFE than in group SFE_Perf (p < 0.05). There was no significant difference in the augmented volume. Fewer subepithelial glands and denser collagen fibres within the sinus membranes were observed in group SFE_Perf than in group SFE. <bold>Conclusions: </bold>A large perforation of the sinus membrane followed by an 8-week healing period did not jeopardize new bone formation following SFE.