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ePaper created 2015-12-29, 14:54:09 | version 1.38.0
38 3_2015 laser 38 laser_opis przypadku I research 10 I laser2_2015 estinthealreadywidelyacceptedpitsandfissuresseal- ing procedures. A simultaneous cleaning, conditioning anddecontaminationinhardlyaccessibledepthsoffis- sures would open a new perspective to this preventive treatment. Er:YAG pre-treatment and subsequent acid etching with highly concentrated phosphoric acid was equivalenttoetchingonly.1 Thelong-termsuccessrate of a fissure sealant depends on its resistance to mi- croleakage, its retention and micromechanical adhe- siontotheenamelsurface,thatisremainingcompletely intact.16, 17 No significant difference in microleakage was re- portedbetweenextendedfissuresealingwithaburand phosphoric acid-etching or Er:YAG and phosphoric acid-etching. Laser irradiation did not eliminate the need for etching enamel.18 Sealing the sound fissures reducestheriskofcariesandtheuseofEr:YAGlaserfor conditioning and enamel sterilisation preserves the tooth surface for a long time. There were some impor- tant differences between the results of various studies inevaluationofthebondstrengthofrestorativemate- rialbondedtoteethsurfacesetchedorconditionedwith Erbiumlaserfamilyandwithacidetchtechnique.These differencescouldbetheresultsoflaserparameters(en- ergyandfrequency)andthetypeofrestorativematerial used. The obtained SEM images showed an increase in retentionofrestorativematerialforthesurfacesirradi- ated by laser and a decrease in bacteria in the pits and fissures,thesterilisationpropertyoflaseronirradiated surfaces is seen. In general, the best results have been obtainedinsimultaneoususeoflaserandacid.1, 19, 20 Etchingpatternofdefectiveenamelisvagueandhas no resemblance to that of normal enamel.21 This could beduetodifferenceinstructureandcompositionofde- fective enamel. Seow W.K. and Amaratunge suggested that variation of etching patterns could be due to dif- ferences in orientation of crystallites relative to the di- rection of attack together with differences in chemical composition between central and peripheral parts of enamel prisms.22 This explanation may highlight the variationinenamelstructurethatcanoccurnotonlybe- tweennormalanddefectiveenamelbutalsofromtooth totooth,orsitetosite,onasingletoothsurface.23 Also, variationofetchingpatternsfordefectiveenamelcould be a result of different aetiology of the enamel defects in different teeth which is unknown.22 These variations may result in problems in bond strength.21 Hypoplastic enamel surfaces prepared with Er:YAG laser LiteTouch are characterised by a rough and regular topography without presence of smear layer in contrast with the surfacestreatedwithacid(Figs.1a&b).Theacidetching of a less organised hypoplastic enamel structure may resultinapatternthatisnottheclassicetchedpattern, which may have a detrimental effect on bonding be- tweentheadhesivematerialsandtheaffectedenamel. Laser ablation procedures change enamel and the sur- faces appeared strong retentive and suitable for adhe- sive restorations.24, 25 Preparation of hypoplastic or hy- pomineralised enamel with Er:YAG laser is a way to re- construct the surface for achievement of better adhe- sion.Ifthesurfaceisnotretentiveenough,theadhesion will be poor and this can compromise the restorations. Laser treatment with Er:YAG laser proposes effective bondstrength.25 _Restorative dentistry Er:YAGlaserwavelengthof2,940nmisstronglyab- sorbedbywater.Itisthuseffectiveandefficientinden- talhardtissueablation.Er:YAGlaserhasbeenstudiedin periodontics29 , restorative30 and surgical treatments31 . A great advantage of Er:YAG is that it has little chance ofpulpaldamageifusedundersufficientwatercooling. Minimal pain has been reported with its use, and it is thus used without local anaesthesia. During cavity preparation, the procedure begins with the use of very low-energy settings of the laser in order to achieve an analgesiceffectonthetoothinvolved.Thenthehigher- powersettingofthelaserisusedinordertoremovethe enamel and expose the infected dentin. Subsequently, thelow-powersettingisusedonceagaintoremovede- cayed dentin.26 Different ablation rates for carious and sound tissue lead to selective removal of carious le- sions.14 Nosmearlayerisformedwiththeapplicationof laser,whichresultsinanincreaseinbondstrengths.14 Er:YAG lasers are selective for carious tissue and comfortable in use. The introduction of a new genera- tion of Er:YAG lasers in 2007 finally made it possible to enjoyadevicethatautomaticallybalanceshighenergy outputwithawiderangeoffrequencyrangesthatfree from conducting settings calculations while treating theirpatients—savingthemtimeandworries.Thereisa laser in the market from the Er:YAG family including pre-set options, with perfectly balanced high energy outputwithawidefrequencyrangealongwiththepre- cision control of pulse duration that fits the selected procedure.Thus,thedentistisconcentratedinhiswork withnoneedforcomplicatedcalculations.Thearrayof indications covers almost every possible treatment of dental hard tissue from simple fissure sealing to cavity preparation.Itisimportanttopointoutthepositiveand preventiveclinicaldentalcarethatisoneofthepromis- ing new modalities used for caries management. The combined fluoride-laser-treatment makes enamel more resistant to acid than do either laser or fluoride treatments alone.27, 28 Er:YAG laser can also transform enamelhydroxyapatiteintofluoridatedhydroxyapatite to reduce enamel solubility as a preventive treatment forenamelcaries.27 Compared to the smooth appearance of the cavity wallsafterburpreparation,cavitymarginsandwallsare irregular but without any smear layer after ablative