Post-extraction soft and hard tissue changes following tissue preservation procedures, prior to implant placement

Background

The extraction of a tooth in the adult dental patient is a common procedure, with the bodies healing response in the alveolus promoting reorganisation and remodelling of the bone and soft tissue, to achieve closure of the wound and re-establishment of homeostasis. This remodelling process is a normal physiological response, which can result in significant changes to the morphology and biological function of the newly formed tissue

Aim/Hypothesis

Heterogeneity exists in the published data regarding the clinical and histological outcomes following ARP. The variation in results has led researchers to conclude that further research was required to develop a clearer understanding of the variability and characteristics of the clinical outcomes.

Material and Methods

This RCT was designed to compare the outcome of undertaking an Alveolar Ridge Preservation (ARP) procedure using a Socket Seal or Guided Bone Regeneration technique (GBR), in combination with a xenograft graft matrix. The control for the trial was an unassisted socket healing site, planned for implant placement at 4-months. The dimensional and tissue characteristics of the extraction site was investigated using clinical measurements, superimposition of CBCT radiographs, merger of CBCT and optical scans and histological analysis of core biopsies.

Results

A small increase in the mean buccal alveolar bone height (0.21 mm SD ± 1.17) was observed when using the GBR technique, with an increase in the height of the lingual surface (0.43 mm SD ± 1.48) also recorded with the SS group. The reduction in the alveolar width was greatest in the control group, at both 5 mm (−4.69 mm SD ± 2.78) and 10 mm (−1.29 mm SD ± 1.15) below the socket margin. The GBR group was associated with the least amount of alveolar width reduction at 5 mm (−0.21 mm SD ± 1.18), with the greatest amount of preservation of the buccal alveolar bone plate. No single ARP technique was associated with increased discomfort during healing, although post-surgical tenderness was higher in the GBR group. Less shrinkage of the gingival mucosa was seen in the GBR group, with a similar reduction in the keratinised tissue width observed in all of the test groups. No difference was found in the ability to place an implant or implant success at 6-months when undertaking ARP.

Conclusion and Clinical Implications

GBR appeared to be associated with less tissue shrinkage and bone resorption than the control group and SS ARP techniques. Increase bone deposition was seen in sites which underwent GBR, with all ARP techniques not seen to be associated with an increase in implant failure.