Comparison of 980 nm diode laser and QMix solution alone and in combination for smear layer removal from root canal surface: A scanning electron microscope study

Title: Comparison of 980 nm diode laser and QMix solution alone and in combination for smear layer removal from root canal surface: A scanning electron microscope study

Abstract:

Smear layer formation is an unavoidable consequence of mechanical root canal instrumentation. This layer may contain organic and inorganic debris, bacteria and bacterial by-products, and can interfere with the penetration of intracanal medicaments and adaptation of obturation materials. Effective smear layer removal is therefore an important objective in endodontic treatment. This study aimed to compare the effectiveness of 980 nm diode laser irradiation and QMix 2in1 solution, used alone and in combination, for removal of smear layer from root canal surfaces.
Forty extracted single-rooted permanent human teeth were selected and prepared to full working length using manual K-files. The prepared samples were divided into four groups of ten teeth each: control group with no final irrigation, QMix 2in1 solution group, diode laser group, and QMix 2in1 solution combined with diode laser irradiation. Following treatment, the roots were split longitudinally and prepared for scanning electron microscopic evaluation. The coronal, middle and apical thirds of the root canals were examined under scanning electron microscopy at 1000x magnification. Remaining smear layer was assessed using the Gutmann smear layer scoring criteria.
The findings showed that the combination of diode laser irradiation with QMix solution resulted in the lowest smear layer scores compared with the other groups. This effect was particularly relevant in the apical third, which is often difficult to clean effectively using conventional irrigation methods due to anatomical complexities and limited irrigant penetration.
The study concluded that 980 nm diode laser activation used in combination with QMix 2in1 solution is an effective method for enhancing smear layer removal from root canal surfaces, especially in the apical third. These findings support the potential role of laser-assisted irrigation as an adjunctive approach in modern endodontic disinfection and canal debridement protocols.

Biography:

Dr. Quratul-Ain Zafar is an Endodontic Consultant, Assistant Professor, examiner, educator and researcher with more than 10 years of clinical and academic experience. She holds BDS, MDS Operative Dentistry & Endodontics, M Endo RCSEd, Fellow in Endodontics RCSEd, Fellow FDS RCPS Glasgow, MFDS RCPS Glasgow, FICD USA, MSc Medical Aesthetics, DHA Dubai Registration in Endodontics, and AI in Healthcare certification from Harvard Medical School. She is the Founder of the Pakistan Association of Laser Dentistry and has special interests in endodontics, laser dentistry, digital dentistry, AI in healthcare, dental education and research.