The Effect of Chlorhexidine and Listerine® Mouthwashes on the Tensile Strength of Selected Absorbable Sutures: An In Vitro Study

BACKGROUND: Suturing plays a critical role in the healing of surgical wounds. The tensile strength of suture materials indicates the ability of the material to withstand stress during knotting and protect the wound during an extended period of healing. OBJECTIVE: An in vitro study was conducted to determine the effect of two commercially available mouthwashes on the tensile strength and breakage mode of two absorbable intraoral sutures. MATERIALS AND METHODS: Two common absorbable sutures, Vicryl® and Monocryl®, both with 4-0 and 5-0 gauges were used. A total of 400 specimens were sutured around rubber rods and immersed in three thermostatically controlled experimental conditions: artificial saliva, 0.2% chlorhexidine gluconate (Parodontax® extra), and essential oils-based rinse (Listerine® Zero™), and these were compared to a nonimmersed dry condition. All specimens were stored in an incubator at 37°C. Tensile strengths were assessed after days 1, 3, 7, 10, and 14 of immersion using a universal Instron® testing machine. The maximum load for suture breakage and the location of the point of breakage were assessed. RESULTS: Unlike Monocryl® 4-0, the tensile strength of both gauges of Vicryl® sutures significantly increased in chlorhexidine and Listerine®. There was a significant decrease in the strength for all suture types after day 10, regardless of the immersion solution. Listerine® significantly reduced the tensile strength of Monocryl® 5-0. CONCLUSION: Oral surgeons and periodontists should be cautious when prescribing commercial mouthwashes for patients relative to their selection of suture materials. However, further studies are needed to understand the molecular changes in sutures when exposed to chemical solutions found in mouthwashes.