13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 30

TITLE: Clinical sealant retention following Er: YAG laser etching compared to acid etching in permanent teeth.

AUTHORS: Lombardi F, Marzo G, Migliau G, Besharat LK, Gallottini L.

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S178.

* doi:10.4317/medoral.17643678

http://dx.doi.org/10.4317/medoral.17643678

Abstract

Introduction: Molars and premolars are the most vulnerable teeth to caries attack. The high susceptibility of these teeth to caries is directly related to morphology of their occlusal surface that prevents both chemical cleaning by saliva and mechanical cleaning by toothbrush. Pit and fissures are therefore the most prone areas to caries and need special protection to prevent carious lesions. Dental sealants are among some of dentistry's most effective tools for preventing tooth decay when applied to pediatric patients' teeth. Retention of the sealant is very essential for its efficiency. Laser pretreatment of dental hard tissues prior to preventive or restorative procedures has been a subject of research. Unground primary enamel bears a prismless superficial layer which is known to be acid resistant.

Aim of the study: To study, evaluate and assess the retention rate of sealants applied to the permanent molars using different enamel surface pre-treatment techniques before placing sealants. This clinical study compared chair-side time required and 4 years retention for three different methods of occlusal surface pretreatment:

I) Traditional acid-etching and rinse technique

II)Er:YAG (KEY Laser, KaVo Dental GmbH, D) laser irradiation without acid-etching

III) Er:YAG (KEY Laser, KaVo Dental GmbH, D) laser irradiation with acid-etching (37% orthophosphoric acid Axia Etch Dentalica, IT) and rinse technique. Material and methods: The sample comprised 75 children whose age ranged from 6 to 8 years and where selected from two dental private clinics in Rome to participate in this controlled study. 4 test teeth per subject were included in the study. Following parental consent 300 noncarious fully erupted first permanent molars were sealed by the same clinician using the three surface pretreatment protocols. After every enamel pretreatment the sealant was applied into occlusal pits and fissures and light cured for 40 sec. All teeth had been cleaned using a brush attached to a rotary instrument without paste (dry brushing) as a preparatory step in the sealant procedure. Salivary contamination is one of the factors that can disturb the sealing process and interfere in the longevity of pit and fissure sealants so at every molar after placing a topical anesthetic we isolated the tooth by placing the rubber dam. Axia Seal (Dentalica, Spa, IT) is a newly developed light-cured resin filled fissure and pit s ealant with fluoride release, fluoride is the only chemical element used for caries prevention. In fact, it favors the remineralisation of initial lesions, prevents the production of polysaccharides essential for the development and sustainment of bacterial plaque, and the absorption of salivary glycoprotein. Fluoride also reinforces enamel, making it less susceptible to caries. Sealant retention was classified as A (fully retained), B (partially lost) or C (completely missing). Chair time required for sealant placement was recorded, and retention rates were determined for each technique. Patients were recalled after 12, 24, 36, 48 and 60 months at which time the pit and fissure sealant retention and the performance of the restorative materials were noted. Clinical evaluation was performed by a single blind examiner. Results were analysed using the software Statistical Package for Social Sciences (SPSS Inc, ver. 13.0, Chicago, IL, USA), chi-squared test was used for statist ical evaluateon of proportions. The mean and standard deviations were subjected to an analysis of variance. Results: The mean age of patients treated was 6.9 years and successful recall was achieved with 100% of patients. Rates of complete retention for occlusal surfaces were not significantly different for the three techniques, although the rate for acid etching combined with laser irradiation was higher than the other two pretreatment techniques. Mean chair time for placement of sealants in the first group was significantly less than in the other two.

Conclusion: Based on the results of this study and taking into consideration the cost and time that a laser preatreatment needs, it was concluded that the use of laser irradiation does not appear to offer a significant advantage over traditional enamel etching methods. Conventional acid etching remains the most effective and simplest technique.