Full versus partial thickness flap to determine differentiation and over keratinization of non‐keratinized mucosa. A 3‐year split mouth randomized pilot study

Abstract

Objectives: It was shown, that Connective Tissue Grafts (CTG) retrieved from the tuberosity tends to determine hyperplastic responses and may induce a beneficial overkeratinization of non-keratinized mucosa. Clinically evaluate and compare CTG from tuberosity ability to increase soft tissue thickness and the keratinization potential after recipient area is either prepared using split or full thickness flap in edentulous mandible.Materials and methods: Fourty implants were placed in 10 edentulous patients with atrophied mandible (Class IV of Misch) presenting less than 1.0 mm of keratinized tissue using a flapless approach and immediately restored with acrylic temporary bridge on multi-unit abutments. The surgical sites were split-mouth randomized and prepared as CTG recipients by a tunneling procedure. Twenty benefited of a partial thickness approach and 20 of a full thickness one. The CTG was placed buccally using partial thickness or full thickness flap according to the randomization schedule. The width of keratinized tissue (KT), the horizontal soft tissue thickness (STT), the marginal hard and soft tissue levels as well as the implant success parameters were collected and analyzed.Results: After a 3 year follow-up period the increase of KT was statistically significantly (p < 0.001) larger in the partial thickness group from 0.6(0.6) to 5.1(0.72) mm, while full thickness group showed very little improvement from 0.5(0.51) to 1(0.57) mm (p < 0.001). STT was significantly increased in both groups over time: from 2.4 (0.88) to 5.4(0.68) mm in full thickness group and from 2.5(0.51) to 5.8(0.41) mm in partial thickness group without any significant difference between the groups. Conclusion:The increase of soft tissue thickness by using CTG from tuberosity was found in both groups, while keratinization of non-keratinized mucosa appeared more in the partial thickness group.

Treatment of Multiple RT1 Gingival Recessions Using a Coronally Advanced Flap Associated with L-PRF or Subgingival Connective Tissue Graft from Maxillary Tuberosity: A Randomized, Controlled Clinical Trial

“…However, while optimal aesthetic results were expected in patients treated with CAF + L-PRF, as confirmed by the literature [24,41], CAF + tCTG was sometimes associated with an unpleasant aesthetic outcome due to the continuous hyperplastic tendency induced using tCTG, possibly related to the excessive thickness of the graft with molecular implications [15,21,35]. The hyperplastic tendency of tCTG has been reported mainly in case reports in periodontal plastic surgery [18] and in studies on ridge augmentations [15] and dental implants [46][47][48]. When hyperplasia was reported in root coverage procedures, it was observed at follow-ups longer than 12 months, exceeding the follow-up duration in our study.…”

Management of hyperplastic tissue response following connective tissue grafting

“…The literature on HTR primarily comprises limited case reports, with a predominant focus on tuberosity grafts and DE-FGG. 7,13,[25][26][27][28][29] Dellavia et al compared tissue composition following augmentation with T-CTG or S-CTG. Tuberosity grafts tended to become hyperplastic after 12 months, and tuberosity graft collagen was more mature and presented higher cross-linking, potentially explaining its higher resistance to metalloproteinase degradation.…”

“…This rare response has mostly been observed in connection with T-CTG. 7,[25][26][27][28][29] However, tissue overgrowth after DE-FGG and S-CTG have also been reported. 7,13, Emerging evidence suggests that CTG may induce HTR in various clinical scenarios, such as gingival recession coverage, pontic site augmentation, or after implant surgery.…”

“…7,13, Emerging evidence suggests that CTG may induce HTR in various clinical scenarios, such as gingival recession coverage, pontic site augmentation, or after implant surgery. 7,13,[25][26][27][28][29] The understanding of HTR is currently limited. Genes related to specific cellular functions, such as collagen biosynthesis, extracellular matrix organization, and cell signaling, likely contribute to this phenomenon and exhibit varying expression levels depending on the donor site.…”

First-in-Human Study to Investigate the Safety Assessment of Peri-Implant Soft Tissue Regeneration with Micronized-Gingival Connective Tissue: A Pilot Case Series Study

“…Therefore, reconstruction or augmentation of adequate peri-implant mucosa is indispensable for successful treatment in dental implants [ 4 , 5 , 6 ]. In clinical practice, the free gingival graft (FGG) and the connective tissue graft (CTG) are currently the gold standards for augmenting keratinized tissue [ 2 , 7 , 8 , 9 , 10 ]. The FGG and the CTG have been used to re-establish the keratinized tissue, correcting mucogingival deformities, and improving the esthetics at teeth and dental implant sites.…”