The interrelationship of restorative dentistry and periodontics is a dynamic one. The interactions between restorative dentistry and periodontal health have been well-documented both clinically and histologically.

The interplay between periodontics and restorative dentistry is present at many fronts, including location of restorative margins, alloy sensitivity, crown contours, and response of the gingival tissues to restorative preparations.

Periodontal tissues form the foundation for proper esthetics, function, and comfort of the dentition, as well as the periodontal health at the restorative gingival interface consider as prerequisite for successful outcome.

Success of fixed prosthodontics restorations is largely dependent upon the long term health and stability of the surrounding periodontal structures.

The purpose of the present study was to evaluate the clinical efficacy of 4 new gingival retraction systems; traxodent, Gingitrac, Nocord, and cord , on the basis of the time taken for placement, hemorrhage control ,the amount of horizontal gingival displacement and periodontal parameter (PI, GI, CAL and PD).

The interplay between periodontics and restorative dentistry is present at many fronts, including location of restorative margins, alloy sensitivity, crown contours, and response of the gingival tissues to restorative preparations.

And from fixed prothodontic point of view there are several factors affect the success and durability of restorations. In general, the type of impression making, setting accuracy, material flow, temperature, humidity, mixing, disinfection and pouring time have effects on the final accuracy of the indirect restorations. Supra-gingival margins are effective in periodontal health maintenance, but do not provide optimal aesthetics.

The primary factor in defective record of marginal details is due to the inefficacy of the gingival displacement technique.

Traditionally, procedures for soft-tissue management and isolation are classified into three main approaches: Mechanical, chemical or surgical.

material and method:-

40 subjects were selected requiring fixed prosthesis according to inclusion and exclusion criteria.

The 4 gingival retraction systems were used on the prepared abutments randomly. The time taken for placement of each retraction system was recorded.

Hemorrhage score will be recoreded. The horizontal retraction was measured on polyether impressions made before the retraction and after retraction using stereoscope.

The periodontal parameter (PI, GI, CAL and PD) will be recorded pre-operative, 1 day post-operative and 7 days post-operative.

Inclusion Criteria:

1. forty patients whose ages more than 18 years were selected requiring fixed prosthesis with minimum of two abutments.
2. Clinically and radiographically healthy gingiva and periodontium around the abutments.
3. Abutment teeth of normal size and contour (no developmental anomaly or regressive age changes).

Exclusion Criteria:

1. Age <18 years.
2. Gingival and periodontal disease.
3. Uncontrolled diabetes, hypertension, hyperthyroidism and other cardiovascular disorders.

unkown the group during recording the results of outcome