**4.1.5 Rinsing**

256 Contemporary Approach to Dental Caries

Difficulties with proper procedure occur during sealing of molars in maxilla (neighboring parotid gland) and in fissures of freshly erupted molars in maxilla and mandible, when a

Masticatory surfaces should be carefully cleaned of bacterial plaque with the use of a hard rotating brush with paste containing a small amount of pumice but no fluorine compounds. Many published reports assess various of cleaning masticatory surfaces before procedure and techniques of applying sealant. One of suggestions is to use a brush dampened with hydrogen peroxide, without pumice. Research demonstrated that after cleaning with pumice, its particles are forced into fissures, which may impair resin's penetration into fissures. Botti et al. assessed cleaning of occlusal surfaces from dental plaque with the use of a synthetic fiber brush and PROPHYflex 3 device (11). The results suggest that the assessed device was the most effective in removing dental plaque compared to cleaning by synthetic fibers. Preparation of masticatory surface by air abrasion was conducted with Air Flow sandblaster at 4.5-7 bars of pressure and at 90° angle from a distance of 1 mm. The abrasive material is aluminum trioxide. The high value of kinetic energy of particles ejected as a stream enables effective preparation of hard tissues. It is recommended to use grains below 50 microns and to abrade intermittently (35,54). Sound systems are based on pneumatic scaler working within the range 6000-6500Hz, vibration amplitude 60-1000 microns. The correct pressure should not exceed 1.5N. Diamond drill bits with 25 and 40 micron coating. Laser etching with Er Cr:YSGG, 2W and 40Hz laser (8) and erbium laser Er:YAG 7W, Er:YAG (5.5W) (49,70,71). Er:YAG laser demonstrates a 15-fold higher water absorption than CO2 laser and 20,000-fold higher than Nd:YAG laser. Activity time is thousandths of a second with a minimal energy dose. The energetic level for enamel ablation is 3.3J/cm3 and for dentine ablation it is 2.8J/cm3. Carisolv system and sodium hypochlorite demonstrated not only effective cleaning of fissures but also antibacterial properties (49,87). Fissure surface preparation with compressed air was assessed by Kramer N *et al.* (43), whereas Mosemi *et al.* studied the impact of masticatory surface preparation with Er Cr YSGG laser and air abrasion, as well as with 37% phosphoric acid on bonding strength on the wall with INSTRON servohydraulic machine. Samples were divided into three groups. In group A, masticatory surface was etched with acid only, in group B air abrasion and acid were applied, and in group C initial etching with laser and phosphoric acid was performed (53). The results indicate that bond strength was highest in the group where air abrasion and acid etching were applied, compared to the group with acid only etching or initial preparation by

After protecting a site from access of saliva, after cleaning and drying, etching procedure can be started. In order to obtain enamel etch, acid solution has to be spread on intercusp fissure surface for 15 seconds. The recommended concentration of phosphoric acid is 37%. The introduction of gel etches allowed to limit the impact of acid used to prepare enamel surface before application of sealant and to decrease the risk of uncontrollable contact of etch with dentine. Gels are applied only once, whereas liquid solutions of acids require multiple application. Etches in the gel form penetrate fissure enamel to the same degree as

fold of mucous membrane covers tooth crown which is not fully erupted.

**4.1.3 Cleaning of masticatory surface** 

means of a laser and phosphoric acid etching (43).

**4.1.4 Etching** 

After etching, the etched surfaces of teeth are rinsed with high pressure water for 10-20 seconds in order to remove acid and residue after the chemical reaction of etching. If etching was performed with an acid in gel form, rinsing time should be doubled.

#### **4.1.6 Drying of etched surface of teeth**

After rinsing the tooth's surface should be dried with compressed air for about 15 seconds and isolated from saliva by dental dam which constitutes a simple and effective method of protecting operative field against infection by microorganisms from saliva. This is necessary because any water remaining after rinsing as well as organic impurities from saliva left on the etched surface, impair sealant's penetration into microfissures, thus decreasing the strength of bonding between sealant and enamel. In case of contact with saliva, etching should be repeated for 15 seconds with subsequent rinsing and drying of the tooth. It should be checked with special attention that the compressed air is not polluted by water or oil.
