Effect of CO2 laser combined with AmF/NaF/SnCl2 solution on the prevention of human and bovine enamel erosion.

This in vitro study evaluated the potential of CO2 laser (10.6 µm) combined with a stannous/fluoride-containing solution for preventing erosion in human/bovine enamel. Forty-eight samples of each substrate were randomly allocated to four groups (n = 12): W - distilled water; E - AmF/NaF/SnCl2 solution; L - CO2 laser; and LE - CO2 laser+AmF/NaF/SnCl2 solution. After surface treatments, samples were submitted to a 5-day erosive challenge, alternating immersions in 0.5% citric acid (2 minutes, 6x/day) and in artificial saliva. Optical profilometry (µm) and scanning electron microscopy (SEM) were used to determine surface loss and surface morphology, respectively. Data were statistically analyzed by two-way ANOVA and Tukey's tests (p < 0.05). For human enamel, tissue loss was lower in group L (12.37 ± 4.46) than in group W (16.45 ± 2.76), and higher than in the groups treated with AmF/NaF/SnCl2 solution (E-5.44 ± 2.37; LE-5.55 ± 2.31). In group L, SEM images reveled a disorganized surface but fewer projections than in group W and LE showed fewer irregularities than W, E, and L. For bovine enamel, tissue loss in group L (13.90 ± 3.50) did not differ from that in group W (14.10 ± 2.98), and was higher than losses in groups E (5.70 ± 2.12) and LE (8.12 ± 2.56), which were statistically similar to each other. Groups W and L had similar aspects of demineralization, whereas groups E and LE showed homogenous surfaces. Surface-treated samples had no changes in their surfaces. CO2 laser was able to slightly prevent surface loss only on human enamel surface, but did not enhance the AmF/NaF/SnCl2 effect on the prevention of enamel erosion.

Effect of CO2 laser combined with AmF/NaF/SnCl2 solution on the prevention of human and bovine enamel erosion

Abstract: This in vitro study evaluated the potential of CO2 laser (10.6 μm) combined with a stannous/fluoride-containing solution for preventing erosion in human/bovine enamel. Forty-eight samples of each substrate were randomly allocated to four groups (n = 12): W - distilled water; E - AmF/NaF/SnCl2 solution; L - CO2 laser; and LE - CO2 laser+AmF/NaF/SnCl2 solution. After surface treatments, samples were submitted to a 5-day erosive challenge, alternating immersions in 0.5% citric acid (2 minutes, 6x/day) and in artificial saliva. Optical profilometry (μm) and scanning electron microscopy (SEM) were used to determine surface loss and surface morphology, respectively. Data were statistically analyzed by two-way ANOVA and Tukey's tests (p < 0.05). For human enamel, tissue loss was lower in group L (12.37 ± 4.46) than in group W (16.45 ± 2.76), and higher than in the groups treated with AmF/NaF/SnCl2 solution (E-5.44 ± 2.37; LE-5.55 ± 2.31). In group L, SEM images reveled a disorganized surface but fewer projections than in group W and LE showed fewer irregularities than W, E, and L. For bovine enamel, tissue loss in group L (13.90 ± 3.50) did not differ from that in group W (14.10 ± 2.98), and was higher than losses in groups E (5.70 ± 2.12) and LE (8.12 ± 2.56), which were statistically similar to each other. Groups W and L had similar aspects of demineralization, whereas groups E and LE showed homogenous surfaces. Surface-treated samples had no changes in their surfaces. CO2 laser was able to slightly prevent surface loss only on human enamel surface, but did not enhance the AmF/NaF/SnCl2 effect on the prevention of enamel erosion.

In situ Effect of CO2 Laser (9.3 µm) Irradiation Combined with AmF/NaF/SnCl2 Solution in Prevention and Control of Erosive Tooth Wear in Human Enamel.

OBJECTIVES: This single-blind, controlled crossover in situ study aimed to evaluate the effect of CO2 laser (9.3 µm) irradiation combined with AmF/NaF/SnCl2 solution on prevention and control of erosive tooth wear (ETW) in human enamel. MATERIALS AND METHODS: Two trial conditions were analyzed, condition 1 as ETW prevention (sound tooth surface) and condition 2 as ETW control (in vitro initial erosive lesion). The experiment was conducted in 2 phases, one with and one without exposure to AmF/NaF/SnCl2 solution. Hundred and ninety-two samples of human enamel (3 × 3 × 1 mm) were randomly divided into 4 experimental groups for each condition: C, without treatment (negative control); F, AmF/NaF/SnCl2 solution (positive control); L, CO2 laser irradiation; and L + F, CO2 laser + AmF/NaF/SnCl2 solution. Twelve volunteers used a removable device, each containing 8 samples per phase. Ex vivo erosive challenges (4 × 5 min/day) and rinsing protocol (1 × 30 s/day) were performed. The surface loss was determined using optical profilometer (n = 12 per group), and the surface morphology was observed with scanning electron microscopy (n = 3). RESULTS: In condition 1, data were analyzed by one-way ANOVA and condition 2 by two-way repeated-measures ANOVA, both with Tukey post hoc tests (α = 5%). In condition 1, groups L (4.59 ± 2.95 µm) and L + F (1.58 ± 1.24 µm) showed significantly less surface loss in preventing ETW than groups C and F. In condition 2, in controlling the progression of ETW, L + F was the only group with no significant surface loss between initial erosive lesion (3.65 ± 0.16 µm) and after erosive challenge (4.99 ± 1.17 µm). CONCLUSIONS: CO2 9.3-µm laser application prevented and controlled ETW progression in human enamel, with greater efficiency when combined with AmF/NaF/SnCl2 solution application.

Efeito in situ do laser de CO2 (9. 3 ? m), associado ou não à solução de AmF/NaF/SnCl2, em prevenir e controlar lesão de erosão em esmalte dental humano / In situ effect of CO2 laser (9. 3 ? m), combined or not with AmF/NaF/SnCl2 solution in prevent and control erosion lesion in human dental enamel

Diversas medidas vêm sendo propostas para a prevenção e controle do desgaste erosivo, como o uso de produtos fluoretados e lasers de alta potência. Este estudo in situ, cego e cruzado, visou avaliar o efeito do laser de CO2 (9.3 ?m), associado ou não a solução de AmF/NaF/SnCl2, na prevenção (Etapa 1: prevenção da lesão, amostras inicialmente hígidas) e controle (Etapa 2: controle da progressão da lesão, amostras previamente erodidas) da erosão dental em esmalte dental humano. As etapas foram divididas em duas fases, uma sem a exposição à solução de AmF/NaF/SnCl2 (Fase I) e outra com (Fase II). Para tanto, 192 fragmentos de esmalte dental humano (3 x 3 x 1 mm) foram divididos, randomicamente, em 4 grupos experimentais em cada etapa (n=12): C - sem tratamento (controle negativo); F - solução de AmF/NaF/SnCl2 (controle positivo); L - irradiação com laser de CO2 (9.3 ? ); L + - laser de CO2 (9.3 ? ) + solução de AmF/NaF/SnCl2. Doze voluntários utilizaram um dispositivo removível inferior bilateral contendo 8 amostras/fase. As amostras foram submetidas ao desafio erosivo ex vivo por meio de sua imersão em ácido cítrico (1,0%; pH 2,3; 5 minutos; 4x/dia em intervalos diferentes para cada fase, durante 5 dias). A perda de superfície foi determinada através da perfilometria óptica (n=12), e a morfologioa de superfície foi observada em Microscopia Eletrônica de Varredura (MEV). Para MEV, foram selecionadas 24 amostras (n=3) submetidas aos 5 dias de ciclagem e, adicionalmente, 24 amostras extras (n=3), submetidas aos tratamentos de superfície. Os dados das amostras da Etapa 1 foram analisados estatisticamente através de ANOVA 1-fator, e as da Etapa 2, através de ANOVA 2-fatores para medidas repetidas (Tempo - lesão inicial e após 5 dias; e Tratamento - C, F, L, L + F); ambos com posterior comparação múltipla através do teste de Tukey. Na análise da Etapa 1, observou-se que os grupos L (4,59 ± 2,95 ? )e L + F (1 58 ± 1 24 ? ) apresentaram melhores resultados na prevenção de lesão de erosão, diferindo estatisticamente dos grupos C e F, os quais não diferiram entre si. E na etapa 2, o grupo L + F (4,99 ± 1,17 ? ) apresentou melhores resultados no controle da progressão da lesão, sendo o único grupo a não apresentar perda de superfície significativa entre lesão inicial e após 5 dias de ciclagem quando comparado com a lesão inicial. Portanto, o laser de CO2 apresentou potencial em prevenir e controlar a progressão de erosão em esmalte dental humano, apresentando maior eficácia quando associado à solução de AmF/NaF/SnCl2.