Discussion : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
In both studies presented above on sinus floor elevation in sheep, all the lateral windows were prepared using a piezoelectric device. In an experiment in rabbits [21], the antrostomies were done with either a sonic instrument or drills to evaluate differences in bone formation in the antrostomy. Elevated space is filled with a collagenated porcine bone similar that used in the present experiment, and both the antrostomies were covered with a collagen membrane. After 8 months of healing, no differences were found between the two sites. However, in a few specimens, the antrostomies presented and incomplete healing, with connective tissue in the central regions. In the antrostomies, new bone was found in a proportion of 28–29%, outcome similar to that observed in the present experiment in the untreated region after 8 weeks of healing (28.6%). However, in the treated antrostomy of the present study, new bone reached the proportion of 35.5%, showing that advantages might be obtained placing the autogenous bone in the antrostomy region, even though the difference was not statistically significant (p = 0.499). A statistically significant difference (p = 0.018) was instead found in the close-to-window regions in which new bone was found in proportions of 25.8% and 17.6% in the treated and untreated sites, respectively.
Aiming to improve the healing at both the elevated space and the antrostomy, precluding the ingrowth of connective tissue within the elevated region, the reposition of the bone window, removed after the osteotomy, has been proposed both in clinical [13, 14] and experimental studies [15, 16].
In a clinical study, 239 implants were installed simultaneously after 96 sinus floor elevation procedures performed in 84 patients [14]. The surgical procedures applied included the reposition of the bone window. After a follow-up of 1 to 6 years, a survival rate of 98.8% was obtained.
The osteogenic properties of the repositioned bone window have been shown in experiments in rabbits in which the maxillary sinus augmentation was performed bilaterally [15, 22]. In both studies, one antrostomy was covered using a collagen membrane while the other was closed repositioning the bone window. More new bone was found within the sinus covered with the repositioned bone window, formed in contact with its inner surface. In another study in rabbits [16], a similar experimental design was applied. Deproteinized bovine bone mineral was used as filler material in both sites, and the repositioned bone window was fixed with cyanoacrylate glue in the test group. A collagen membrane was applied in the control sites, and the healing was evaluated after 2, 4, and 8 weeks. No differences were found in the healing within the elevated space. In the antrostomy region of the test sites, the bone window was partly remodeled in the periphery and connected by bridges of newly formed bone to the inner regions of the grafted sinus. However, in the collagen membrane sites, the healing was incomplete in some specimens, presenting residual defects occupied by connective tissue. This agrees with the outcomes of the present study, that reported four antrostomies not closed and three closed, two of which presenting remaining defects. In the treated sites, two antrostomies were found not completely closed and five obliterated by bone, three of which with remaining defects.
Serial posts:
- Abstract : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Introduction : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- Introduction : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- Materials and methods : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- Materials and methods : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- Materials and methods : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [3]
- Results : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- Results : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- Discussion : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- Discussion : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- Discussion : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [3]
- Availability of data and materials : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Abbreviations : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- References : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- References : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- References : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [3]
- References : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [4]
- Funding : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Author information : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [1]
- Author information : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits [2]
- Ethics declarations : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Additional information : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Rights and permissions : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- About this article : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Table 1 Histomorphometric analysis. Tissues evaluated in the various regions after 1 week of healing : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Table 2 Histomorphometric analysis. Tissues evaluated in the various regions after 8 weeks of healing : Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits
- Fig. 1. Clinical view of the surgical procedures. a Tibial bone exposed for autogenous bone harvesting using a bone scraper. b Antrostomies prepared. c Autogenous bone particles placed in the antrostomy. d Xenograft and bone particles (red arrow) at the antrostomies. e Collagen membranes placed on the antrostomies. f Wounds closed with sutures : Influence of the use of autogenous bone particles
- Fig. 2. The various regions evaluated at the histomorphometric analyses. Bone walls (red arrow); middle (white arrow); sub-mucosa (yellow arrow); close-to-window (orange arrow). The antrostomy region was also evaluated at the medial and lateral edges (dark green arrows) and in the middle aspect (light green arrow) : Influence of the use of autogenous bone particles
- Fig. 3. Photomicrographs of decalcified sections illustrating the healing after 1 week. a Treated site. Bone strips occupying the antrostomy and the subjacent area (close-to-window region). b Untreated site. Note the new bone-forming from the sinus bone walls. Scarlet-acid fuchsine and toluidine blue stain. Images grabbed at × 20 magnification : Influence of the use of autogenous bone particles
- Fig. 4. Photomicrographs of ground sections. a) Treated site. Bone residues (examples in yellow asterisks) included in soft tissue containing fibroblast-like cells and inflammatory cells. b) Untreated site. Xenograft residues (examples in red asterisks) surrounded by soft tissue rich in fibroblast-like cells. Scarlet-acid fuchsine and toluidine blue stain. a) 200 x magnification.; b) 100 x magnification : Influence of the use of autogenous bone particles
- Fig. 5. Photomicrographs of decalcified sections illustrating the healing after 8 weeks. Both at the treated (a) and untreated (b) sites, the antrostomy was closed in most cases, presenting residual defects of various dimensions in the outer side. New bone was connecting the lateral and medial sinus walls. The middle and sub-mucosa regions were not healed completely yet. Scarlet-acid fuchsine and toluidine blue stain. Images grabbed at × 20 magnification : Influence of the use of autogenous bone particles