A Study to Treat Patients With Edentulous Mandibles With Two Straumann 3.3mm Diameter Bone Level Implants

Jaw, Edentulous Clinical Trial

Official title: A Randomized, Controlled, Double Blind, Clinical Trial to Treat Patients With Edentulous Mandibles With Two Straumann 3.3mm Ø Bone Level Implants Which Will be Restored With a Removable Prosthesis by Comparing Two Different Implant Alloys in Split Mouth Design

Status Completed

Clinical Trial Summary

The purpose of this study is to assess the change of crestal bone level at the Titanium Zirconium (TiZr) compared to Titanium (grade IV) implant between surgery and 6, 12, 24, and 36 month post surgery.

Clinical Trial Description

This is a clinical trial to compare crestal bone level changes, soft tissue parameters, implant success and survival between small diameter implants in edentulous mandibles restored with removable overdentures.

An initial patient evaluation will be conducted to determine wether a patient meets the study inclusion and exclusion criteria.

The edentulous subjects will undergo surgery for placement of two dental implants, the test and control implant. The implants will be placed in the intraforaminal region.

A gingival former will be inserted in the implant after implant placement to ensures a transmucosal healing. After 6 to 8 weeks the healing abutments will be retrieved and the locator abutments will be connected to the implant.

The removable prosthesis will be prepared and connected to the implants two weeks later.

The study will be blinded until 12 month post surgery and completed with an unblinded follow up period up to 3 years.

Straumann will deliver the randomization envelopes to the sites which had been created by an independent Clinical Research Organization (CRO). The randomization envelopes are marked with a sequential number. The master randomization list will be kept at Straumann.

The success and survival of the implants, soft tissue conditions, success of the prosthesis part and product safety will be assessed after 6, 12, 24, and 36 month after surgery.

Source data verification will be performed by qualified study monitors to assess the accuracy, completeness, or representativeness of registry data by comparing the data to external data sources.

Data will be recorded on standardized Case Report Forms for all study subjects from whom informed consent is obtained. The investigator will be responsible for the accuracy of the data entered on the Case Report Forms. All source documents pertaining to this study will be maintained by the investigator and made available for inspection by authorized persons.

Sample size calculations are proceeded for a given range of clinical relevant differences between test and control implant and a given range of standard deviations with the two sided paired t-test under a significance level of 0.05 and with a power of 80 percent.

To be robust against deviations from the assumption of normality and to take into account possible dropouts it is good clinical practice to increase the calculated sample size by about 10 to 20 percent.

To detect a clinical relevant difference down to 0.1 with a standard deviation of 0.3, one needs 73 plus 15 (88) patients for the study.

Management of dropouts and missing data will depend on their frequency and the particular outcome measure. Any such adjustments will be described completely. All data will be included in the analysis. If outliers are determined to exist, an additional analysis excluding such outliers may be performed and the rationale for such exclusion will be described completely.

A first data analysis including data up to 12 month after surgery is planned after all patients have completed the respective study period. Inferential statistical analysis at this stage will be restricted to the primary efficacy parameter. The final data analysis will be performed after all patients have completed the study.

Categorical data will be described as contingency tables with frequencies and percentage, whereby the dominator for percentages is defined as the number of patients in the respective analysis set. Continuous data will be summarised by mean, standard deviation, minimum, 1st quartile, median, 3rd quartile and maximum. Also the number of missing and nonmissing values will be given.

Tables will be presented by device type and or total, as appropriate. Preabutment connection values will serve as baseline values. Hypothesis tests will be carried out at a two sided significance level of 5 percent, except for the primary efficacy analysis. The confirmatory noninferiority test will be performed at a one sided 2.5 percent significance level.

As usual for secondary, no adjustment os significance level for multiple testing will be performed.

In case of unacceptable deviations from the statistical model assumption, transformations of the data, the use of different distributional models or nonparametric approaches will be considered.

All statistical calculations and analyses will be performed using the Statistical Analysis System (SAS) version 9.1.13 or higher. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Jaw, Edentulous
• Mouth, Edentulous

• NCT number: NCT00905840
• Study type: Interventional
• Source: Institut Straumann AG
• Status: Completed
• Phase: N/A
• Start date: November 2007
• Completion date: September 2011