Comparative analysis of lateral maxillary sinus augmentation with a xenogeneic bone substitute material in combination with piezosurgical preparation and bony wall repositioning or rotary instrumentation and membrane coverage: a prospective randomized clinical and histological study

Abstract

Objectives: The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation.

Materials and methods: Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches.

Results: Forty implants were placed and 29 harvested biopsies could be evaluated. Duration of surgery, membrane perforations, and VAS were detected. Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%).

Conclusions: The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results.

Clinical trial: clinicaltrials.gov NCT04811768.

Clinical relevance: Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.

Keywords: Bony wall repositioning; Collagen membrane; Dental implant; Maxillary sinus floor augmentation; Piezoelectric surgery; Xenografts.

Conflict of interest statement

Dr. Balint Molnar received a grant from the “Young researchers program” from NSK Europe GmbH, Eschborn, Germany.

© 2022. The Author(s).

Figures

Fig. 1

Exemplary images of the implantation procedure in the bony wall (BW) group. A Piezoelectric window preparation, B cerabone insertion, C bony wall repositioning, D periosteal sutures, E mucosal sutures, F 6 months reentry, G guided biopsy harvesting, H core biopsy, and I implant insertion

Fig. 2

Exemplary images of the implantation procedure in the collagen membrane (CM) group. A Rotary window preparation, B sinus mucosa elevation, C cerabone insertion, D collprotect membrane coverage, E periosteal sutures, F mucosal sutures, G 6 months reentry, H core biopsy, and I implant insertion

Fig. 3

Exemplary total scans of the analyzed sinus biopsies and the histomorphometrical measurements. A Marking of the total implant area (blue line) within a sinus biopsy. B Marking of the fraction of new bone formation (yellow lines). C Marking of the remaining bone substitute fraction (red lines) (Masson Goldner-staining, × 100 magnification)

Fig. 4

Exemplary overviews of biopsies form A the bony wall (BW) group and B the collagen membrane [CM] group. In both groups, newly formed bone tissue (red asterisks) was grown throughout the complete implantation area of the xenogeneic bone substitute (blue hashes). The tissue distribution, i.e., the amounts of newly formed bone, remaining bone substitute, and connective tissue (green points) were comparable (“total scan,” von Kossa staining, × 100 magnifications)

Fig. 5

Exemplary histological images from the collagen membrane (CM) group showing the integration behavior of the xenogeneic bone substitute material (BSM) that was observed in both study groups without any differences. A The material granules were mainly embedded within newly grown bone matrix (red asterisks). CT = connective tissue (von Kossa staining, × 100 magnification, scalebar = 50 µm). B and C New bone formation (black asterisks) was regularly observed at the BSM surfaces associated with active osteoblasts (blue arrow in C) indicating that the bone growth process was still in process. At the surface areas that were covered by connective tissue (CT) mainly macrophages (black arrows) and single multinucleated giant cells (black arrowhead) were detected. Interestingly, osteoclasts (yellow arrowhead) were regularly found in direct neighborhood of these areas and their cellular arrangement did not significantly differ from the material-associated giant cells. NB = newly formed bone tissue, blood vessels = red arrows (Masson Goldner staining, × 400 magnifications, scale bars = 10 µm)

Fig. 6

Results of the histomorphometrically measured tissue distribution (** p < 0.01). BW: bony wall group, CM: collagen membrane group