Microleakage at Sealant/Enamel Interface of Primary Teeth: Effect of Er:YAG Laser Ablation of Pits and Fissures

Resident: Cho

Author(s): Borsatto, M et al.

Journal: Journal of Dentistry for Children

Year. Volume (number). Page #’s: 2004. 71. 143-147.

Major topic: Sealant, Er-YAG Laser

Minor topic: Acid Etch

Type of Article: Scientific Article

Main Purpose: The purpose of this study was to assess microleakage at the sealant/enamel interface on primary molars after treatment of occlusal pits and fissures with 3 different techniques: conventional acid etching; Er:YAG laser ablation + acid etching; Er:YAG laser ablation.

Overview of method of research: Human primary molars extracted within a 6 month period were cleaned and examined under a x20 magnifier to discard those with structural defects. Thirty teeth were selected for the study and stored in 0.9% saline solution with a 0.4% sodium azide at 4^oC. The apices were sealed with a light-cured resin composite and teeth were assigned randomly into 3 groups. Group I was treated with 37% phosphoric acid gel for 30 seconds. Group II was treated with Er:YAG laser device emitted at 2.94um wavelength for 40 seconds and then treated with 37% phosphoric acid gel for 30 seconds. Group III was treated with Er:YAG laser device emitted at 2.94um wavelength for 40 seconds. Afterwards, all groups were treated with a uniform layer of pit-and-fissure sealant (Fluroshield, Dentsply/Caulk, Milford, Del); the sealant was light cured for 20 seconds. The retention of the sealant was verified with an explorer. Microleakage was assessed by staining the teeth with 0.2% rhodamine B solution and viewing them at x25 magnification. Axion Vision 3.1 software was used to obtain quantitative data of dye penetration at the enamel/sealant interface.

Findings: The microleakage percentage recorded for Er:YAG laser ablation (group III) was higher than those that incorporated phosphoric acid etch as one of the steps (groups I and II). No significant difference was found between group I and II.

Key points/Summary: The use of phosphoric acid etching led to less marginal leakage in sealants than Er:YAG laser ablation. Er:YAG laser beam does not have continuous emission and does not provide homogeneous etching of the tooth surface, leaving nonlased areas between pulses.

Assessment of Article: This article reinforces the value of acid etching prior to sealant placement and informs us that Er:YAG laser ablation is not an effective substitute for acid etch. However, one must also recognize that this is an in-vitro study and does not take into consideration other factors including saliva contamination.