STUDY ON THE EFFECTS OF ACID ETCHING ON AFFECTED ENAMEL

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1 Odontology STUDY ON THE EFFECTS OF ACID ETCHING ON AFFECTED ENAMEL Abstrct The purpose of the study ws to estblish nd compre the effects of ortophosphoric nd hydrochloric cids on the enmel ffected by incipient crious lesions different evolution. Mterils nd method. 20 teeth cute nd chronic non-cvitry crious lesions were considered for the study. The teeth were sectioned in two hlves through the middle of the non-cvitry lesions. The hlves of 5 white spot-type lesions nd of 5 brown spot-type ones were nlyzed s to their surfce roughness, on n tomic force microscope (AFM). 5 hlves white spot-type lesions nd 5 hlves brown spot-type ones were subjected to cid 37% ortophosphoric cid (Scotchbond etchnt gel, 3M ESPE), nd n equl number of smples ws subjected to the ction of 15% hydrochloric cid (ICON-etch, DMG Dentl Products Ltd) for 2 min, then wshed wter nd nlyzed by AFM. Results. The initil surfce roughness of the enmel ws higher in the white spot type crious lesions, comprtively the brown spot-type ones. For both types of crious non-cvitry lesions, cid phosphoric nd hydrochloric cid significntly incresed the surfce roughness of the enmel, comprtively the sttus of the enmel surfce prior to. The hydrochloric cid led to surfce roughness significntly higher thn in the cse of ortophosphoric cid, in both cute nd chronic non-cvitry crious lesions. The roughness vlues obtined through ortophosphoric nd hydrochloric cid were higher in the white spot-type crious lesions, comprtively the brown spot-type ones. Conclusions. Both the 37% ortophosphoric cid nd the 15% hydrochloric cid determined significntly higher surfce roughness of the enmel ffected by cute nd chronic non-cvitry crious lesions. The surfce condition of the brown spot-type crious lesions ws less significntly modified, comprtively tht of the white spot-type lesions, by the ction of either ortophosphoric or hydrochloric cid. Keywords: white spot-type lesions, brown spot-type lesions, phosphoric cid, hydrochloric cid, AFM The discovery of crious lesion considered s too incipient to be restored imposes, in most cses, solution of expecttive type. Infiltrtion of the crious lesions low-viscosity resins Simon Stoleriu 1, Ginin Iovn 2, Glin Pncu 1, A. Georgescu 1, Antoni Moldovnu 1, S. Andrin 3 1. Assist. Prof., Dept Odontology, Fculty of Medicl Dentistry, Gr.T.Pop U.M.Ph. Isi 2. Assoc. Prof. PhD, Dept. Odontology, Fculty of Medicl Dentistry, Gr.T.Pop U.M.Ph. Isi 3. Prof. PhD, Dept. Odontology, Fculty of Medicl Dentistry, Gr.T.Pop U.M.Ph. Isi Corresponging uthor: Sorin Andrin, sorinndrin@yhoo.com ppers s vible solution for preventing the dvnce of the lesions. The ICON (DMG Dentl products Ltd) system belongs to new ctegory of products, occurring in n intermedite position between those utilized in prevention nd those pplied for restoring the crious lesions. The technology of micro-invsive infiltrtion chrcteristic to ICON my be pplied for the tretment of the crious lesions occurring on smooth surfces nd lso on the proximl ones, up to the externl dentinry third. The ICON system is cpble of stopping the dvnce of the incipient crious lesions of the enmel nd of eliminting the spect of the white spot-type lesions. Nevertheless, penetrtion of the mteril my be difficult, becuse of the surfce lyer of the nturl crious lesions, chrcterized by high minerliztion. The im of the study ws to estblish nd compre the effects determined by the ction of the ortophosphoric nd hydrochlorhic cids upon the enmel ffected by incipient crious lesions different evolution. MATERIALS AND METHOD 20 teeth cute nd chronic non-cvitry crious lesions, divided into 2 groups, ccording to the type of evolution of the crious lesions 10 teeth cute nd other 10 chronic lesions were considered for the study. The teeth were sectioned in two hlves through the middle of the non-cvitry lesions. The hlves of 5 white spot-type lesions nd of 5 brown spot-type ones were nlyzed s to their surfce roughness, on n tomic force microscope (AFM). 5 hlves white spot-type lesions nd 5 hlves brown spot-type ones were subjected to cid 37% ortophosphoric cid Interntionl Journl of Medicl Dentistry 353

2 Simon Stoleriu, Ginin Iovn, Glin Pncu, A. Georgescu, Antoni Moldovnu, S. Andrin (Scotchbond etchnt gel, 3M ESPE), for 30 sec, wshed distilled wter for other 30 sec, vcuum-dried nd then subjected to AFM nlysis. Other 5 hlves of the crious lesions white spot-type lesions nd 5 brown spottype lesions were subjected to the ction of 15% hydrochloric cid (ICON-etch, DMG Dentl Products Ltd) for 2 min, then wshed wter nd nlyzed by AFM t the Petru Poni Institute of Mcromoleculr Chemistry of Isi. RESULTS The 3D nd 2D spects of white spot-type lesion fter ortophosphoric cid re illustrted in figures 1 nd 2. The spect of the 2 ìm section demonstrtes the presence of some roughness vrible sizes. Figure 3. Aspect of the histogrm for white spot-type lesions fter phosphoric cid Aspects 3D nd 2D of white spot-type lesion fter 1% hydrochloric cid re illustrted in figures 4 nd 5. Some heterogeneous irregulrities, more intense thn when using ortophosphoric cid, my be observed on the 10 m section. Figure 1. 3D spect of white spot-type lesion fter cid 37% ortophosphoric cid Figure 4. 3D spect of white spot-type lesion under the ction of 15% hydrochloric cid Figure 2. 2D spect of white spot-type lesion fter cid 37% ortophosphoric cid The vrition intervl of the roughness vlues rnged between 100 nd 250 nm (fig. 3) Figure 5. 2D spect of white spot-type lesion under the ction of 15% hydrochloric cid 354 volume 1 issue 4 October / December 2011 pp

3 STUDY ON THE EFFECTS OF ACID ETCHING ON AFFECTED ENAMEL The vrition intervl of the roughness vlues rnged between 150 nd 270 nm (fig. 6). The vrition intervl of the roughness vlues rnged between 100 nd 220 nm (fig. 9), which re much higher vlues thn in the cse of enmel sections, prior to the ction of the gent. Figure 6. Aspect of the histogrm for the white spottype lesions following hydrochloric cid For the brown spot-type crious lesions, spects 3D nd 2D fter 37% ortophosphoric cid re presented in figures 7 nd 8. The 2 m section evidences the presence of some heterogeneous irregulrities. Figure 9. Aspect of the histogrm for the brown spottype lesions fter phosphoric cid Aspects 3D nd 2D of brown spot-type lesion fter the ction of 1% hydrochloric cid re presented in figures 10 nd 11. Some heterogeneous irregulrities, more intense thn when using ortophosphoric cid, my be observed on the 10 m section. Figure 7. 3D spect of brown spot-type lesion fter the ction of 37% ortophosphoric cid Figure 10. 3D spect of brown spot-type lesion fter the ction of 15%hydrochloric cid Figure 8. 2D spect of brown spot-type lesion under the ction of 37% ortophosphoric cid Interntionl Journl of Medicl Dentistry 355

4 Simon Stoleriu, Ginin Iovn, Glin Pncu, A. Georgescu, Antoni Moldovnu, S. Andrin chloric cid produced higher surfce roughness thn the ortophosphoric cid, both in the cse of cute nd chronic crious non-cvitry lesions (tble 1). Tble 1. Root men squre roughness vlues for white nd brown spot-type lesions prior to nd fter phosphoric nd hydrochloric cids Figure 11. 2D spect of brown spot-type lesion fter the ction of 15% hydrochloric cid The roughness vlues given in the histogrm rnged between 100 nd 250 nm. (fig. 12) Figure 12. Aspect of the histogrm for brown spottype lesions fter hydrocloric cid Smple 1 Smple 2 Smple 3 Smple 4 Smple 5 Root men squre roughness brown spot (nm) Reference After After hydrochloric phosphoric cid cid , Root men squre roughness white spot (nm) Reference After After phosphoric hydrochl cid oric cid The roughness obtined through ortophosphoric cid ws more intense in the white spot-type crious lesions, comprtively the brown spot-type ones. The sme tendency ws observed, too, for hydrochloric cid, the roughness vlue registered for white spot-type lesions being higher thn for the brown spot-type ones (tble 1). As differences were observed between the vlues recorded fter cid both types of cid, comprtively the reference group, for both white spot- nd brown spot-type lesions, the dt were sttisticlly nlyzed the Wilcoxon test for pir smples. Tble 2. Result of the Wilcoxon test compring surfce roughness in the cse of brown spot-type lesions Test Sttistics b The root men roughness vlues for white nd brown spot-type lesions, prior to nd fter cid hydrochloric nd ortophosphoric cids, re listed in tble 1. Mention should be mde of the presence of n initil surfce roughness of the enmel, much higher in the cse of white spot-type crious lesions, comprtively the brown spot-type ones. For both types of crious non-cvitry lesions, cid phosphoric nd hydrochloric cid incresed the surfce roughness of the enmel, comprtively the condition of the enmel surfce prior to. The hydro- Sttisticlly significnt differences were registered between the surfce roughness vlues of the brown spot-type lesions fter phosphoric cid, comprtively the refer- 356 volume 1 issue 4 October / December 2011 pp PABS - RBS Asymp. Sig. (2-tiled) HABS - RBS HABS PABS Bsed on negtive rnks. b. Wilcoxon Signed Rnks Test PABS- phosphoric cid brown spot HABS-hydrocloric cid brown spot RBS- reference brown spot

5 STUDY ON THE EFFECTS OF ACID ETCHING ON AFFECTED ENAMEL ence (z = 2.023, two-tiled = 0), between surfce roughness vlues of the brown spot-type lesions fter hydrochloric cid, comprtively the reference (z = 2.032, twotiled = 0.042), s well s between the surfce roughness vlues fter phosphoric cid, comprtively the hydrochloric one (z = 2.023, two-tiled = 0) (tble 2). Tble 3. Result of the Wilcoxon test compring surfce roughness in the cse of white spot-type lesions Asymp. Sig. (2-tiled) Test Sttistics b AF Mnn-Whitney U.000 Wilcoxon W Asymp. Sig. (2-tiled) Test Sttisticsb PAWS - RWS Tble 4. Results of the Mnn Whitney test compring the surfce roughness of white nd brown spot-type lesions following the ction of phosphoric cid HAWS - RWS HAWS PAWS Exct Sig. [2*(1-tiled Sig.)].008. Not corrected for ties. b. Grouping Vrible: Roughness. Bsed on negtive rnks. b. Wilcoxon Signed Rnks Test PAWS- phosphoric cid white spot HAWS-hydrocloric cid white spot RWS- reference white spot Also, sttisticlly significnt differences were observed between the surfce roughness vlues of the white spot-type lesions fter phosphoric cid, comprtively the reference (z = 2.023, two-tiled = 0), s well s between the surfce roughness vlues fter phosphoric cid, comprtively the hydrochloric one (z = 2.023, two-tiled = 0) (z = 2.023, two-tiled = 0) (tble 3). Tble 5. Results of the Mnn Whitney test compring the surfce roughness of white nd brown spot-type lesions following the ction of hydrochloric cid Test Sttistics b AC Mnn-Whitney U Wilcoxon W Asymp. Sig. (2-tiled) Exct Sig. [2*(1-tiled Sig.)] As differences were observed between the roughness vlues recorded fter cid phosphoric nd, respectively, hydrochloric cid, in the cse of white spot-type lesions, comprtively the brown-type ones, the dt were sttisticlly nlyzed the MnnWhitney test for independent smples. Sttisticlly significnt differences were registered between the roughness vlues of the white spotnd brown spot-type lesions in the cse of both 15% hydrochloric (tble 4), nd 37% ortophosphoric cid (tble 5). Interntionl Journl of Medicl Dentistry Not corrected for ties. b. Grouping Vrible: Rugozitte DISCUSSION Infiltrtion of crious non-cvitry enmel lesions resins ppers s promising lterntive for stopping their dvnce. The reltive impermebility of the surfce lyer of the nturlly crious lesions my prevent resin s penetrtion inside them, so tht this lyer should be removed prior to infiltrtion. The hydrochloric cid ppered s very suitble for the erosion of this superficil lyer (1). 357

6 Simon Stoleriu, Ginin Iovn, Glin Pncu, A. Georgescu, Antoni Moldovnu, S. Andrin Chemicl tretment through increses enmel s topogrphy, modifying it from wekly rective surfce to more susceptible to dhesion one. Etching removes pproximtively 10 ìm of enmel s surfce, creting porous morphologicl lyer ( depth between 5 nd 50ìm) (2). The retention chrcteristics of the conditioned enmel surfce depend on the type of cid, time of cid s ction nd chemicl composition of enmel (3-7). Selection of n gent should lso consider its dissocition constnts (8). The cids low dissocition constnt re preferred in more diluted solutions, comprtively those high dissocition constnt. The dissocition constnts of the cids employed in the present study re of 7 for the hydrochloric cid nd of 2.1, respectively, for the phosphoric cid. The hydrochloric nd phosphoric cids were utilized s bleching gents both seprtely or in ssocition (9-13). Direct ppliction of the 18% hydrochloric cid for 100 sec determined depth loss of enmel of 100±47ìm (Tong LSM, 1993). SEM exmintion put into evidence common pttern of the enmel in the res treted 18% hydrochloric cid. Severl studies evluted the depth of conventionl dhesives penetrtion into the nturl crious lesions fter pre-tretment two different types of cid gels in vitro. Proximl crious lesions of the white spot-type were etched for 120 sec 37% phosphoric gel nd 15% hydrochloric cid gel, then infiltrted n dhesive resin. The verge depth of penetrtion when using hydrochloric cid ws significntly higher thn phosphorous cid (58±37ìm versus 18±11ìm). (14). The conclusion reched by the uthors is therefore tht cid 15% hydrochloric cid is more suitble thn 37% phosphoric cid, s pre-tretment for the crious lesions to be filled resins. A study performed by Meyer-Lueckel H et l. in 2007 compred the efficiency of the vrious types of cid gels, pplied through vrious techniques, for removing the surfce lyer of the crious lesions. The lesions were treted 37% phosphoric nd 15% hydrochloric cid for 30 up to 120 sec, significnt reductions of the surfce lyer being noticed when using 15% hydrochloric cid for 90 nd, respectively, 120 sec, comprtively the ppliction of phosphoric cid for sec (15). Nevertheless, no difference ws observed s to the depth of the erosions in crious lesions, comprtively the surfce of the helthy enmel. The present study lid stress on the efficiency of surfce lyer removl by ppliction of hydrochloric cid for sec. CONCLUSIONS Both the 37% ortophosphoric cid nd the 15% hydrochloric cid determined sttisticllysignificnt increse of surfce roughness of the enmel ffected by cute nd chronic crious lesions. The surfce condition of the brown spottype crious lesions ws less significntly modified thn tht of the white spot-type ones, under the ction of both ortophosphoric nd hydrochloric cids. References 1. Pris S, Meyer-Lueckel H, Stiebritz M, Kielbss AM. Surfce Lyer Erosion of Enmel Cries Lesions in Primry Teeth in Preprtion for Resin Infiltrtion. Cries Res. 2007,41(2): Gwinnett AJ. Histologic chnges in humn enmel following tretment cidic dhesive conditioning gents. Arch Orl Biol. 1971,16: Silverstone LM: Fissure selnts: Lbortory studies. Cries Res 8: 2-26, idm O, Hill G: Phosphoric cid concentrtion: Enmel surfce loss nd bonding strength. J Prosthet Dent 1986, 55: Legler LR, Retief DH, Brdley EL, Denys FR, Sdowsky PL: Effects of phosphoric cid concentrtion nd etch durtion on sher bond strength of n orthodontic bonding resin to enmel: n in vitro study. Am J Orthod Dentofc Orthop 1989, 96: Legler LR, Retief DH, Brdley EL: Effects of phosphoric cid concentrtion nd etch durtion on enmel depth of etch: An in vitro study. Am J Orthod Dentofc Orthop 1990, 98: Crstensen W: The effects of different phosphoric concentrtions on surfce enmel. Angle Orthod 1992, 62: volume 1 issue 4 October / December 2011 pp

7 STUDY ON THE EFFECTS OF ACID ETCHING ON AFFECTED ENAMEL 8. Bertolotti RL: Conditioning of the dentin substrte. Oper Dent 1992, 5(Suppl): McCloskey RJ. Atechnique for removl of fluorosis stins. J Am Dent Assoc 1984, 109: Croll TP, Cvnugh RR. Enmel color modifiction by controlled hydrochloric cid-pumice brsion. I. Technique nd exmples. Quint Int 1986, 17: Croll TP. Enmel microbrsion: the technique. Quint Int 1989, 20: Croll TP. Enmel microbrsion for removl of superficil dysminerliztion nd declcifiction defects. JAm Dent Assoc 1990, 120: Powell KR, Crig GG. A simple technique for the esthetic improvement of fluorotic-like lesions. JDent Child 1982, 49: Pris S, Meyer-Lueckel H, Colfen H, Kielbss AM. Penetrtion coefficients of commercilly vilble nd experimentl composites intended to infiltrte enmel crious lesions. Dent Mter 2007, 23(6): Meyer-Lueckel H, Pris S, Kielbss AM. Surfce lyer erosion of nturl cries lesions phosphoric nd hydrochloric cid gels in preprtion for resin infiltrtion. Cries Res 2007, 41(3): Interntionl Journl of Medicl Dentistry 359