The smear layer created by scaling and root planing is physiologically eliminated in a biphasic process

Abstract

Mechanical instrumentation of the root surface causes the formation of a smear layer, which is a physical barrier that can affect periodontal regeneration. Although different procedures have been proposed to remove the smear layer, there is no information concerning how long the smear layer persists on root surfaces after instrumentation in vivo. This study assessed the presence of the smear layer on root surfaces over a 28-day period after subgingival instrumentation with hand instruments. Fifty human teeth that were referred for extraction because of advanced periodontal disease were scaled and root planed (SRP) by a single experienced operator. Ten teeth were randomly assigned to be extracted 7, 14, 21, and 28 days after SRP. Another 10 teeth were extracted immediately after instrumentation (Day 0, control group). The subgingival area of the instrumented roots was evaluated with scanning electron microscopy. Representative photomicrographs were assessed by a blinded and calibrated examiner according to a scoring system. A rapid and significant (p < 0.05, Z test) initial reduction in the amount of smear layer was observed at 7 days, and a further significant (p < 0.05) decrease was observed 28 days after SRP. Interestingly, even 28 days after SRP, the smear layer was still present on root surfaces. This study showed that the physiological elimination of the smear layer occurred in a biphasic manner: a rapid initial reduction was observed 7 days after instrumentation, which was followed by a slow process leading to a significant decrease 28 days after instrumentation.

A Comparative Evaluation of Efficacy of Root Surface Biomodification using MTAD, MTAD+I-PRF on Adhesion of Fibrin Clot to Dentin Sem Study

“…We know that the mechanical debridement done as part of periodontal therapy leaves a smear layer covering the debrided root surface. [ 1 10 ] Various chemicals like citric acid, EDTA, and tetracycline plus techniques like laser have shown successful eradication of the smear layer. [ 11 12 ] As a final endodontic irrigant to clean the canal and eliminate the smear layer, Torabinejad et al .…”

“…Many studies have examined various chemical conditioning techniques since the possibility of periodontal regeneration could rise with the successful removal of the smear layer. [ 1 ] In practice, such smear layers over the root can be dissolved by subjecting the root to chemical treatment using agents such as citric-acid-4.25%, Ethylenediaminetetraacetic (EDTA)-17%, Tetracycline hydrochloride acid-10% and phosphoric acid-37%. After dissolving the smear layer, the collagen is exposed on the root surface, thereby facilitating the attachment of fibroblasts to the root.…”

Comparative evaluation of fibrin network formation after root conditioning using erbium, chromium-doped yttrium scandium gallium and garnet laser, ethylene-diamine-tetra-acetic acid, and tetracycline on dentin: A scanning electron microscopic study

“…who observed that after instrumentation there was a presence of a heavy smear layer, fewer fibrin network formation, or appearance of blood cells. [ 12 , 13 ] According to Matsuoka et al ., they stated that Er, Cr: YSGG laser utilized with water was successful in debris and SLR when compared to the control group (SRP). [ 14 ] The mechanism of the removal of smear layer by the Er, Cr: YSGG laser is based on the expansion and implosion of vapor lock and secondary cavitation effect.…”

A Local Desiccant Antimicrobial Agent as an Alternative to Adjunctive Antibiotics in the Treatment of Periodontitis: A Narrative Review

“…Subgingival mechanical instrumentation accumulates debris onto the root surfaces, also known as the smear layer ( Figure 2 a–c), which limits the spreading of specialized cells and impairs periodontal wound healing [ 86 , 92 ]. Several adjunctive subgingivally applied agents may enhance the removal of the smear layer and stimulate the colonization of specialized cells [ 77 , 93 ], thus creating the premises for the development of a new connective tissue attachment [ 86 , 92 ]. However, some products, such as citric acid, tetracycline, or EDTA, did not provide any additional clinical benefits in an attempt to regenerate an affected periodontium [ 94 ].…”