Dimensional ridge changes in conjunction with four implant timing protocols and two types of soft tissue grafts: A pilot pre‐clinical study

Abstract

Aim: To determine the effect of (1) implant placement timing and (2) the type of soft tissue graft in terms of ridge profile changes.Materials and Methods: Four implant treatment modalities were applied in the mesial root areas of the third and fourth mandibular premolars of 10 mongrel dogs alongside connective-tissue graft (CTG) and volume-stable cross-linked collagen matrix (VCMX): immediate, early, and delayed placement (DP), and DP following alveolar ridge preservation (ARP). All dogs were sacrificed 3 months after soft tissue augmentation. Standard Tessellation Language files from designated time points were analysed.Results: Compared with the pre-extraction situation, the median width of the ridge demontstrated a linear increase only in group ARP/CTG (0.07 mm at the 2-mm level), whereas all other groups showed a reduction (between À1.87 and À0.09 mm, p > .05). Groups ARP/CTG (0.17 mm) and DP/CTG (0.05 mm) exhibited a profilometric tissue gain in a set region of interest (p > .05). The net effect of CTG and VCMX ranged from 0.14 to 0.79 mm. Conclusions: Dimensional ridge changes varied between treatment protocols. ARP with CTG led to the smallest difference in ridge profile between the pre-extraction and the study end time point. Both CTG and VCMX enhanced the ridge contour. K E Y W O R D S connective tissue graft, implant placement, tissue remodelling, volume-stable cross-linked collagen matrix Clinical Relevance Scientific rationale for study: Effects of implant placement timing (immediate placement, early placement, and delayed placement [DP] with or without alveolar ridge preservation [ARP]) and soft tissue augmentation types (connective-tissue graft [CTG]; volume-stable cross-linked collagen matrix [VCMX]) have previously been compared only among selected combinations. There has been no previous thorough investigation encompassing the various treatment modalities within a single model.

Effects of implant placement timing and type of soft‐tissue grafting on histological and histomorphometric outcomes in a preclinical canine model

“…That thickness was comparable to the values in the groups with CTG other than group IP/CTG. Our primary study using STL analyses had shown a similar trend (Lee et al, 2022). The linear tissue gain was also largest in group EP/VCMX.…”

“…The present study found that CTG tended to result in larger overall and soft‐tissue thicknesses in all implant placement protocols compared with VCMX, despite our primary STL analyses revealing that both CTG and VCMX enhanced the overall tissue contour (Lee et al, 2022). This indicates that clinicians should be careful in case selection in their decision making about using an autogenous soft‐tissue transplant or a soft‐tissue substitute material (Cosyn et al, 2022).…”

“…Details of the surgical procedures can be found in our previous study (Lee et al, 2022). Four surgeries were performed on each animal, with an interval of 1 month between consecutive surgeries.…”

“…Because of the above‐described situation, we previously implemented two soft‐tissue volume augmentation treatments (CTG and volume‐stable collagen matrix [VCMX]) and four implant placement timings (IP, EP, and DP with/without alveolar ridge preservation [ARP]) in our primary preclinical model. Clinical and profilometric outcomes were assessed using digital scanning data by superimposing Standard Tessellation Language (STL) files (Lee et al, 2022). That study found that all combinations were effective in increasing the soft‐tissue volume and, thereby, improving the ridge profile.…”

Effect of polydeoxyribonucleotide with xenogeneic collagen matrix on gingival phenotype modification: a pilot preclinical study

“…To overcome these drawbacks, several collagen-based matrices have been developed and evaluated in both clinical and preclinical settings. Although these collagen matrices have demonstrated promising results, their performance generally has not exceeded, or has even been inferior to, that of SCTG in terms of soft tissue volume gain [ 10 11 12 ]. Furthermore, significant volume shrinkage has been observed over time at sites treated with collagen matrix.…”