Increased Peri-implant Keratinized Mucosal Thickness at Different Operative Times

Peri-Implantitis Clinical Trial

Official title:

The Effect of Different Surgical Timing on the Clinical Efficacy of Increasing the Thickness of Keratinized Mucosa Around a Single Posterior Implant: a Prospective, Randomized Controlled Clinical Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04683991
• Other study ID #: 2020-782
• Status: Recruiting
• Phase: N/A
• Start date: May 27, 2021
• Est. completion date: December 31, 2023

Study information

• Verified date: January 2021
• Source: Second Affiliated Hospital, School of Medicine, Zhejiang University
• Contact: Weilian Sun, PhD
• Phone: 13757119563
• Email: weiliansun[@]zju.edu.cn
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Keratinized mucosa, which is composed of free gingiva and attached gingiva, is a barrier against bacterial invasion in oral cavity and provides good tissue sealing for periodontal environment. When the keratinized mucosa is insufficient, it is difficult to maintain the long-term stability of the implant, which is not conducive to the peri-implant health. It is generally believed that enough keratinized mucosa width is beneficial to reduce plaque accumulation and reduce the incidence rate of peri-implant diseases. In recent years, clinicians have gradually recognized that the thickness of keratinized mucosa plays an important role in maintaining the peri-implant health. Some researchers found that the thickness of mucosa is very important to maintain the aesthetic effect of implant restoration, and when the thickness of mucosa around the implant is less than 2mm, alveolar bone absorption will occur to maintain a stable biological width. A meta-analysis showed that when the thickness of the keratinized mucosa around the implant was greater than 2mm, the amount of marginal bone loss was significantly reduced (- 0.8mm, P < 0.0001).

It is considered that autogenous soft tissue graft is the most reliable technology to augment keratinized mucosa. Subepithelial connective tissue graft (SCTG) is a mucogingival surgery that transplant autologous free connective tissue under the pedicled semi thick flap to augment keratinized mucosa. It can effectively increase the thickness of soft tissue, cover the exposed implant, and reconstruct the interdental papilla. It is the gold standard for peri-implant soft tissue agumentation. Keratinized mucosal thickening surgery may be done prior to the surgical phase, after the surgical phase, before loading, or even after loading. It is believed that keratinized mucosal thickening at the same time of implantation can effectively reduce the possibility of mucosal recession after implantation, reduce the amount of marginal bone absorption in the process of osseointegration, which is conducive to maintaining the long-term stability of the implant. For the sake of clear clinical vision and convenient operation, clinicians often choose to thicken the keratinized mucosa during the secondary operation, and also obtain good postoperative effect. However, after the completion of the final repair, the keratinized mucosa thickening surgery increases the difficulty of operation and the technical requirements for the operator. In clinical practice, it is rarely selected to perform keratinized mucosal thickening at this time. At present, the effectiveness of timing on the outcome of soft tissue augmentation is still debated, and, most importantly, a direct comparison between simultaneous and staged procedures remains underexplored.

Therefore, this clinical trial is to prospectively compare the clinical efficacy of simultaneous versus delayed timing of soft tissue augmentation by SCTG placement around single implants, by evaluating the peri-implant marginal bone level change and soft tissue change, so as to provide reference for the formulation of clinical treatment plan and the selection of the best operation time.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 34
• Est. completion date: December 31, 2023
• Est. primary completion date: June 30, 2023
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• No systemic diseases or pregnancy;

• The thickness of keratinized mucosa where the posterior tooth is missing is less than 2 mm;

• Full-mouth plaque score (FMPS) < 20% (measured at four sites per tooth) and bleeding on probing score (BOP%) =25% (measured at six sites per tooth);

• Periodontal condition is stable, no probing depths =5 mm;

• No previous soft tissue augmentation procedure at experimental site;

• The patient has signed informed consent and accepts the operation of subepithelial connective tissue transplantation.

Exclusion Criteria:

• Patients with uncontrolled hypertension;

• Patients with uncontrolled diabetes;

• Patients with insufficient oral hygiene and Untreated periodontitis;

• Pregnant or lactating women;

• Smoker;

• Patients with long-term (> 6 months) use of glucocorticoids;

• History of malignancy, radiotherapy, or chemotherapy for malignancy within the past 5 years;

• Patients with severe cardiovascular problems;

• Patients with uncontrolled infectious or metabolic diseases;

• Patients with substance abuse.

Related Conditions & MeSH terms

• Dental Implants
• Peri-Implantitis

Intervention

Procedure:
• Subepithelial connective tissue graft
A de-epithelialized connective tissue graft is harvested from the homolateral palate and transplanted around the implant.

Locations

Country	Name	City	State
China	Department of Oral Medicine, the Second Affiliated Hospital, School of Medicine Zhejiang University	Hangzhou	Zhejiang

Sponsors (1)

Lead Sponsor	Collaborator
Second Affiliated Hospital, School of Medicine, Zhejiang University

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	peri-implant marginal bone level change	The bone level of the proximal and distal sites of the implant is measured by oral X-ray parallel projection method. Compare the image value with the actual value to calculate the actual bone level.	18 months
Secondary	peri-implant clinical attachment level change	The distance between the reference point of impression edge and the bottom of gingival groove around the implant.	18 months
Secondary	peri-implant keratinized mucosa width	keratinized tissue measured as the distance between muco-gingival junction and the gingival margin.	18 months
Secondary	peri-implant keratinized mucosa thickness	gingival thickness measured 1.5 mm coronal to the MGJ using an injection needle, perpendicular to the tissue surface, with a silicon stop over the gingival surface.	18 months
Secondary	peri-implant gingival index	Periodontal probe was used to measure 6 sites on buccal and lingual side each time to observe gingival color, texture and bleeding, and record the scores.	18 months
Secondary	peri-implant gingival recession	The distance between the implant shoulder and the gingival margin of the temporary or final crown was measured with a periodontal probe (only when the implant shoulder was visible).	18 months
Secondary	visual analogue scale	Visual analogous scale ( VAS) suggested by WHO was used to assess. Analgesia intensity expressed with 0-10, 0 point as without pain completely, 10 points as unbearable pain.	18 months