Smear Removal and Collagen Exposure After Non‐Surgical Root Planing Followed by Etching With an EDTA Gel Preparation

Abstract

Low pH aqueous solutions of citric acid have been used in surgical periodontal therapy mainly for two reasons. It dissolves smear after a relatively short exposure time and it has been claimed to selectively remove root surface-associated mineral exposing collagen to varying degrees. The use of low pH etching agents has recently been challenged in both experimental in vitro and in vivo studies based on their necrotizing effect on the surrounding periodontal tissues. The purpose of the present study was to assess the efficacy of subgingival application of an EDTA gel preparation in removing smear and exposing collagen fibers in root surfaces following non-surgical periodontal therapy. Root surfaces which were root planed did not reveal any patent dentinal tubuli or collagen fibers. This was in contrast to the findings seen after root planing followed by etching, where intertubular surfaces were covered by a dense fibrillar network extending into patent dentinal tubuli. In high magnification these intertubular fibers displayed the cross-striated texture typical for collagen fibers. Etching of root planed surfaces with EDTA may thus enhance the effect of non-surgical root debridement in the same way as has been shown during experimental surgical procedures.

Effects of Citric Acid and EDTA on Periodontally Involved Root Surfaces: A SEM Study

“…2,3,7 Smear layer is formed irrespective of the treatment modality used, 3 i.e. ultrasonic, curette or diamond bur.…”

Root Biomodification in Periodontics - The Changing Concepts

“…Some drawbacks associated with citric acid application include formation of extremely acidic environment in the surrounding tissues, which may result in unfavourable wound healing responses [10]. Its low pH has also been shown to induce cytotoxic effects when in direct contact with periodontal cells [34].…”

“…The goal of this regeneration procedure is to determine the alterations of disease root surface that would create an appropriate and hospitable surface for cell attachment and eventually development of fibre attachment [9]. Mechanical instrumentation (scaling and root planing) leaves a smear layer, which affects cell reattachment and can serve as a reservoir for microbial growth [10]. Therefore, chemical conditioning of the roots has been performed to remove the smear layer and improve biocompatibility.…”

Histological analysis of effects of 24% EDTA gel for nonsurgical treatment of periodontal tissues

“…Perhaps the most frequently attempted type of regeneration has involved chemical modification of the root surface (1). The purpose of this chemical modification is mainly to remove the smear layer that results from scaling and root planning (2,3), to remove endotoxins, to open dentinal tubules, as well as to expose collagen fibers from root surfaces (4)(5)(6)(7). Therefore chemical modification has been used as an adjunct to scaling and root planning to facilitate reattachment of periodontal ligament fibers (3,8).…”