Comparison of Artificial Saliva vs Saline Solution on Rate of Suture Degradation in Oropharyngeal Surgery

Absorbable sutures are designed to degrade and lose strength over time. Manufacturers warn that exposure to various body fluids can change the estimated degradation rate of these sutures, but few studies have been conducted to quantify the degree of change associated with saliva.

To quantify the association of increased loss of strength of sutures over time after exposure to artificial saliva (hereinafter referred to as "saliva").

This experimental in vitro study was conducted at Bucknell University (Lewisburg, Pennsylvania) from June 19, 2015, to July 4, 2015. No participants were involved. The loss of strength over time of sutures submerged in physiological saline and artificial saliva solutions was compared. Three types of absorbable sutures commonly used in oral surgery were tested: chromic, poliglecaprone 25, and polyglactin 910. Data analysis was conducted from July 15, 2016, to August 16, 2016.

The primary outcome measure was 50% strength reduction. To measure breaking strength, 6 knotted sutures of each type were pulled to failure at regular time intervals after immersion in either saline or synthetic saliva at 37°C. Regression analysis was used to interpret strength degradation profiles and to estimate the time to reach 50% of the original breaking strength.

Of the 3 suture types submerged in the 2 solutions, all 3 degraded to 50% strength faster (by 2 to 13 days) in saliva than in saline. The differences in the degradation profiles varied by suture type. Poliglecaprone 25 sutures demonstrated a sudden decrease in failure strength between day 5 and day 8 in both solutions, but the decrease was greater in saliva (-10.2 N; 95% CI, -15.5 to -4.9 N) than in saline (-6.1 N; 95% CI, -11.2 to -0.9 N). The polyglactin 910 and chromic sutures share a similar degradation profile when implanted in tissue, but saliva was associated with more degradation of chromic sutures. Differences in degradation rate were seen in polyglactin 910 sutures after day 6 (saline: -0.9 N/d; 95% CI, -1.0 to -0.7 vs saliva: -1.2 N/d; 95% CI, -1.4 to -1.1). After day 2, chromic sutures had a degradation rate of -0.3 N/d (95% CI, -0.5 to -0.2) in saline and -0.5 N/d (95% CI, -0.6 to -0.3) in saliva.

Knowing the association of saliva with suture degradation rates of various suture types may enable oropharyngeal surgeons to select sutures that retain their strength and degrade at an appropriate rate to allow for the effective healing of the wound.