Surface and mineral changes of enamel with different remineralizing agents in conjunction with carbon-dioxide laser

ABSTRACT

Aim: The aim of this study was to evaluate the surface/mineral changes on enamel before and after the application of acidulated phosphate fluoride (APF) gel, fluoride enhanced hydroxyapatite gel and propolis in conjunction with carbon-dioxide (CO₂) laser. Materials and Methods: Crowns of 40 human maxillary central incisors were collected and were divided into four groups of 10 each: Topical fluoride application only, topical fluoride application followed by CO₂ laser irradiation, CO₂ laser irradiation followed by topical fluoride application and CO₂ laser irradiation before and after topical fluoride application. The 10 crowns in each group was again sectioned into four equal parts of mesio-incisal, disto-incisal, mesio-cervical and disto-cervical sections rendering 40 samples in each group. Each group was again subdivided into four subgroups: Subgroup C - untreated enamel surface (control). Subgroup A - APF gel application, subgroup R - fluoride enhanced hydroxyapatite gel application and subgroup P - propolis application. The surface morphology of the test samples were analyzed by scanning electron microscopy and mineral changes by energy dispersion X-ray spectrophotometer. Results: Total mineral content is maximum in Group 4A (CO₂ laser irradiation before and after APF gel application) and calcium/phosphate ratio is highest in Group 4R (CO₂ laser irradiation before and after Remin-Pro application). Group 2A (APF gel application followed by CO₂ laser irradiation) has the maximum fluoride retention. Conclusion: Laser irradiation of enamel through a topically applied APF gel is effective in the prophylaxis and management of dental caries.

Key words:

Acidulated phosphate fluoride gel - carbon-dioxide laser - fluoridated hydroxyapatite gel - propolis - total mineral content

• REFERENCES

• 1 Stern RH, Vahl J, Sognnaes RF. Lased enamel: Ultrastructural observations of pulsed carbon dioxide laser effects. J Dent Res 1972; 51: 455-60
• 2 Stern RH, Sognnaes RF, Goodman F. Laser effect on in vitro enamel permeability and solubility. J Am Dent Assoc 1966; 73: 838-43
• 3 Yamamoto H, Ooya K. Potential of yttrium-aluminum-garnet laser in caries prevention. J Oral Pathol 1974; 3: 7-15
• 4 Yamamoto H, Sato K. Prevention of dental caries by acousto-optically Q-switched Nd: YAG laser irradiation. J Dent Res 1980; 59: 137
• 5 Nelson DG, Shariati M, Glena R, Shields CP, Featherstone JD. Effect of pulsed low energy infrared laser irradiation on artificial caries-like lesion formation. Caries Res 1986; 20: 289-99
• 6 Nelson DG, Wefel JS, Jongebloed WL, Featherstone JD. Morphology, histology and crystallography of human dental enamel treated with pulsed low-energy infrared laser radiation. Caries Res 1987; 21: 411-26
• 7 Tagomori S, Morioka T. Combined effects of laser and fluoride on acid resistance of human dental enamel. Caries Res 1989; 23: 225-31
• 8 Oho T, Morioka T. A possible mechanism of acquired acid resistance of human dental enamel by laser irradiation. Caries Res 1990; 24: 86-92
• 9 Fox JL, Yu D, Otsuka M, Higuchi WI, Wong J, Powell G. Combined effects of laser irradiation and chemical inhibitors on the dissolution of dental enamel. Caries Res 1992; 26: 333-9
• 10 Kato IT, Kohara EK, Sarkis JE, Wetter NU. Effects of 960-nm diode laser irradiation on calcium solubility of dental enamel: An in vitro study. Photomed Laser Surg 2006; 24: 689-93
• 11 Hicks MJ, Flaitz CM, Westerman GH, Berg JH, Blankenau RL, Powell GL. Caries-like lesion initiation and progression in sound enamel following argon laser irradiation: An in vitro study. ASDC J Dent Child 1993; 60: 201-6
• 12 Westerman GH, Hicks MJ, Flaitz CM, Blankenau RJ, Powell GL, Berg JH. Argon laser irradiation in root surface caries: In vitro study examines laser's effects. J Am Dent Assoc 1994; 125: 401-7
• 13 Westerman GH, Hicks MJ, Flaitz CM, Powell GL, Blankenau RJ. Surface morphology of sound enamel after argon laser irradiation: An in vitro scanning electron microscopic study. J Clin Pediatr Dent 1996; 21: 55-9
• 14 Esteves-Oliveira M, Pasaporti C, Heussen N, Eduardo CP, Lampert F, Apel C. Prevention of toothbrushing abrasion of acid-softened enamel by CO (2) laser irradiation. J Dent 2011; 39: 604-11
• 15 Giamalia I, Steinberg D, Grobler S, Gedalia I. The effect of propolis exposure on microhardness of human enamel in vitro . J Oral Rehabil 1999; 26: 941-3
• 16 Anić I, Vidović D, Luić M, Tudja M. Laser induced molar tooth pulp chamber temperature changes. Caries Res 1992; 26: 165-9
• 17 Tepper SA, Zehnder M, Pajarola GF, Schmidlin PR. Increased fluoride uptake and acid resistance by CO2 laser-irradiation through topically applied fluoride on human enamel in vitro . J Dent 2004; 32: 635-41
• 18 Wu CC, Roan RT, Chen JH. Sintering mechanism of the CaF2 on hydroxyapatite by a 10.6-l microm CO₂ laser. Lasers Surg Med 2002; 31: 333-8
• 19 Márquez F, Quintana E, Roca I, Salgado J. Physical-mechanical effects of Nd: YAG laser on the surface of sound dental enamel. Biomaterials 1993; 14: 313-6
• 20 Lee BS, Lin CP, Hung YL, Lan WH. Structural changes of Er: YAG laser-irradiated human dentin. Photomed Laser Surg 2004; 22: 330-4
• 21 Pai N, McIntyre J, Tadic N, Laparidis C. Comparative uptake of fluoride ion into enamel from various topical fluorides in vitro . Aust Dent J 2007; 52: 41-6
• 22 Featherstone JD, Barrett-Vespone NA, Fried D, Kantorowitz Z, Seka W. CO₂ laser inhibitor of artificial caries-like lesion progression in dental enamel. J Dent Res 1998; 77: 1397-403