Soft these studies has been done in a

Soft tissue in vicinity of a full veneer restoration, requires careful treatment planning
considerations and management. Not only the final restoration and periodontal harmony, also the
atraumatic management of soft tissues to create unobstructed access to preparation finish line, is
an important consideration during fixed prosthodontic treatment. This is more critical during final
impression making, when preparation finish line is placed deeper within the gingival sulcus.
Critical sulcular width of 0.2mm is reported in the literature. Less than this would result in an
inappropriate and unacceptable impression. Thus, gingival retraction or displacement is a
recommended procedure before final impression making, to displace marginal gingiva away from
the tooth, and to provide access for impression material of sufficient thickness, to the finish line
region of the prepared abutment. Various methods for gingival displacement are available. These
are, mechanical(copper band, plain retraction cord), chemical(astringent liquids), chemicomechanical
(cord with medicaments, cordless paste or foam), surgical (electrocautery, laser) and
combination of these. Chemico-mechanical method by cord with medicament, is the most popular
method for gingival displacement. The materials and techniques, involved in this method have
been subjected to large research. Along with this, the clinical predictability and success, positioned
them as the gold standard, over which newer methods can be compared. But, as the cord is pushed
within the sulcus by clinician, they poses a chance of unavoidable destructive force transfer to
delicate gingival attachment, patient discomfort and risk of irreversible gingival injury. These
disadvantages have led to invention of cordless displacement paste (expasyl, traxodent) and foam
(magic foam cord) system. These materials require placement around the gingival sulcus, in
conjunction with application of cotton compression cap (traxodent, magic foam cord). Various
research showed less destructive force generation and better biological compatibilty of paste
retraction system. However, studies on clinical effectiveness of paste retraction system, showed
conflicting results. Subjective evaluation of sulcus dilatation and final impression quality showed
no significant difference between cord and paste retraction system. Objective measurement of
lateral gingival displacement showed, significantly more displacement with cord retraction system,
in most of the studies. Whereas, few studies showed either no significant difference between both
the system, or better displacement with paste retraction system. Most of these studies has been
done in a supragingival margin situation. Whereas, ideal subgingival margin placement is
recommended upto 0.5mm within the gingival sulcus. Only one study, in such situation, reported
the better effectiveness by 2- cord retraction system over paste retraction system. But 2- cord
retraction system can cause more tissue injury and less patient tolerance to the restorative
procedure. No study in the literature reported the comparative effectiveness of single cord
retraction system and paste retraction system with compression cap. Also, impression materials of
variable viscosity, were used in previous studies, along with different technique. As different
impression materials and methods might have caused different displacing force, the true
effectiveness both system might have remained concealed. No previous study reported a proper
impression planning for minimizing the influence of displacing force from impression material
viscosity, and thereby more accurate measurement of retraction system efficacy. However, various
material properties and methods for impression making are well reserched and documented in the
literature. From these information, a customized impression making can be planned for particular
research purpose. The purpose of this research was to compare the efficacy of cord retraction
system (single plain knitted retraction cord + hemostatic solution) and cordless paste retraction
system (Traxodent Hemodent paste + retraction cap), on lateral gingival displacement. The null
hypothesis was that, there will be no significant difference in lateral gingival displacement between
cord and paste retraction system.