Effect of Ozone and CO2 Laser on Dental Caries Progression

Laser irradiation and Ozone therapy have been suggested as potential treatments for the management of dental caries.  Objective: To assess the effect of CO₂ laser irradiation and ozone application on induced carious lesions in experimental rats. Methods: Ninety albino rats were kept on a cariogenic diet for 4 months to induce dental caries. At the end of the induction period when dental caries initiation was evident in the posterior teeth, the rats were randomly divided into 3 experimental groups. In each group the left side molars acted as untreated controls (C) while the right side molars received the experimental treatments (T). Group I: teeth were treated with pulsed 10.6 µm CO₂ laser (Surgilase, USA) at 2W for 2 seconds. Group II: teeth were received a wash of ozonized water of concentration of 20 µgm/ml. This was followed by the application of ozone gas (OzoneLabª Model OL80) with a concentration of 3000 ± 10% ppm, at a flow rate of 125 ml/min. for 60 sec. Group III: teeth received a combination of the two previously described techniques. After treatment application, the rats were fed the same cariogenic diet for an additional two months. The animals were then sacrificed and the teeth examined for caries using the DIAGNOdent (Kavo, Germany) and QLF (Inspektor, Netherlands) caries-measurement systems.  Results: The data are presented as mean and standard deviation of the relative caries measurements for each of the 3 group in the table below.

Groups	DIAGNOdent		QLF (ΔF)		QLF (WSA)
	T	C	T	C	T	C
GI	27.74 ± 3.85 a	68.98 ± 9.51	19.54 ± 2.41 a	45.90 ± 5.35	0.37 ± 0.08 a	1.30 ± 0.21
GII	25.23 ± 3.93 b	68.99 ± 9.54	17.34 ± 2.94 b	46.01 ± 5.87	0.31 ± 0.09 b	1.31 ± 0.15
GIII	24.96 ± 3.71 b	67.86 ± 7.09	17.26 ± 2.21 b	46.34 ± 4.34	0.28 ± 0.05 b	1.31 ± 0.09

Statistical analysis of the data obtained from DIAGNOdent and QLF (ΔF & WSA) values showed that there was a significant difference between the treatment and control groups (p = 0.003) for each of the 3 experimental treatments. Groups with the same superscript letter indicate no significant difference using the Bonferroni stepdown post hoc analysis.  Conclusions: Ozone, CO₂ laser, and the combination of the two treatments significantly reduce caries progression in experimental rats.