Fissure caries inhibition with a CO 9.3-μm short-pulsed laser-a randomized, single-blind, split-mouth controlled, 1-year clinical trial.

Objectives: The objective of this randomized, single-blind, split-mouth controlled, clinical trial was to evaluate whether the use of a short-pulsed 9.3-μm CO laser increases the caries resistance of occlusal pit and fissures in addition to fluoride therapy over 12 months.

Materials And Methods: A total of 60 participants, average age 13.1 years, were enrolled. At baseline, second molars were randomized into test and control, and assessed by ICDAS, SOPROLIFE, and DIAGNOdent. An independent investigator irradiated test molars with a CO laser (wavelength 9.3 μm, pulse duration 4 μs, pulse repetition rate 43 Hz, beam diameter 250 μm, average fluence 3.9 J/cm, 20 laser pulses per spot). Test molars received laser and fluoride treatment, control teeth fluoride alone. Fluoride varnish was applied at baseline and at 6 months. After 6 and 12 months, teeth were again assessed.

Results: A total of 57 participants completed the 6-month and 51 the 12-month recall. Laser-treated surfaces showed very slight ICDAS improvements over time with ICDAS change - 1 in 11% and 8%, no changes (ICDAS change 0) in 68% and 67%, and slightly worsened (ICDAS change 1) in 19% and 24% at 6- and 12-month recalls, respectively, and worsened by two scores in 2% at both recall time points. Control teeth showed significantly higher ICDAS increases, with 47% and 25% showing ICDAS change 0, ICDAS change 1 in 49% and 55%, and ICDAS change 2 in 4% and 20% at 6- and 12-month recalls, respectively. Differences in ICDAS changes between the groups were statistically significant (P = 0.0002 and P < 0.0001; Wilcoxon's signed-rank test, exact). A total of 22% of the participants developed ICDAS 3 scores on the control teeth.

Conclusions: Microsecond short-pulsed 9.3-μm CO laser irradiation markedly inhibits caries progression in pits and fissures in comparison with fluoride varnish alone.

Clinical Relevance: The 9.3-μm CO laser irradiation of pits and fissures enhances caries resistance.

Trial Registration: ClinicalTrials.gov identifier: NCT02357979.