Procedures for Improving the Mucosa Around Implants

This research study is looking at three different procedures for improving the oral mucosa (membrane) around dental implants. The three procedures will be the standard procedure, the standard procedure with the use of tissue harvested from the mouth and the standard procedure with the use of Mucograft membrane product. An advantage claimed by the Mucograft manufacturer is increased patient comfort due to lack of tissue harvesting from the mouth. Pain and discomfort levels will be evaluated for each of the procedures. Gain in oral mucosa and the visual will also be evaluated.

Experimental Design

The study design for this research project will be a single centered, prospective randomized controlled trial. Subjects will be Tufts University School of Dental Medicine Department of Periodontology patients.

Sample Size and Statistical Analysis

There will be up to 22 subjects in each group, with a total of up to 66 subjects in the study. Up to 80 subjects will be enrolled in order to have 66 subjects completed the study. The calculation is based on 2 point difference in VAS pain and discomfort survey to have 80% power, while setting α=0.025 to adjust for the two primary outcomes (pain and discomfort) which gives 19 per each group. However, considering a 15% drop out rate, up to 22 subjects for each group will be recruited.

Data collected for analysis will be 10 point VAS from subjects' survey forms for the primary outcome. And 10 point VAS from esthetic evaluation, gain of keratinized mucosa measured by periodontal probe in millimeters with stent will be data for secondary outcome.

For all variables, normality will be assessed using the Kolmogorov-Smirnov test. If the assumptions of normality hold, then means and standard deviations will be reported and the relationship between treatment arm and the outcome will be tested using one-way ANOVA. If the assumptions of normality do not hold, then medians and interquartile ranges will be reported and relationships will be tested using the Kruskal-Wallis test. If the initial analyses are significant, then the post hoc pair wise comparisons will be made using either independent sample t-tests or Mann-Whitney U-tests. When patients are lost to follow-up, their information will be excluded from the analyses. To account for the multiple comparisons, the Bonferroni correction will be implemented. Thus, all p-values less than 0.025 will be considered statistically significant. Analyses will be performed using SAS, Version 9.2 (SAS Institute, Cary, NC).

Eligibility Criteria:
Inclusion Criteria:

* Patient scheduled for 2nd stage implant surgery at the periodontology clinic of TUSDM.
* Inadequate keratinized tissue (0.1mm- \<2mm of buccal keratinized mucosa prior to the time of 2nd stage surgery) at the implant site. \[4\]
* Adequate depth of buccal vestibule (\>7 mm from the crest of ridge, measured at the center of surgical area) to accommodate gain of keratinized mucosa width.

Exclusion Criteria:

* Lack of keratinized mucosa on the area of implant.
* Autoimmune conditions which may interfere with soft tissue healing in oral cavity, e.g., pemphigus vulgaris, phemphigoid
* Infectious disease (self-reported - HIV, tuberculosis or hepatitis)
* Pregnant patients, as part of TUSDM standard of care not to treat for non-emergency surgical procedures
* Uncontrolled diabetes, defined as HbA1c \>=7, values measured within six months
* Previous gingival grafting procedure on the area.
* Smoking (\>3 cigarettes per day)
* Subjects with known hypersensitivity to study materials or objection to use of porcine material (religious or cultural reasons)
* Known allergy to codeine