ABSTRACT
Objective: This study evaluated the influence of calcium lactate and sodium fluoride mouthwashes on enamel microhardness and dentin permeability during in-office bleaching. Material and Methods: For the microhardness evaluation, enamel blocks were randomly submitted to different treatments associated with in-office bleaching agent using 40% hydrogen peroxide (Opalescence Boost PF 40%/ Ultradent; 3 sessions x 40-minute each) (n = 10): 1) Control: application of bleaching agent; 2) Calcium lactate: 1-minute immersion before bleaching treatment; 3) Sodium fluoride: immersion for 1 minute before bleaching treatment; 4) Calcium lactate + sodium fluoride: 1 minute immersion in calcium lactate solution, followed by 1 minute immersion in sodium fluoride before bleaching treatment. Dentin discs received the same treatment protocols (n = 10) to evaluate permeability. Knoop microhardness and dentin permeability assessments were performed twice (at baseline and 48 hours after the end of bleaching treatment). Results: The generalized linear model considering the design of repeated measures over time showed that there was no significant difference between treatments (p = 0.9577) and between assessments (p = 0.3267) regarding Knoop microhardness. Kruskal Wallis and Dunn tests showed that calcium lactate immersion before bleaching treatment provided higher dentin permeability than other groups (p = 0.0009). Conclusion: The use of sodium fluoride solution and calcium lactate in association with in-office bleaching treatment did not influence the microhardness of tooth enamel, although calcium lactate may increase dentin permeability. (AU)
Objetivo: Este estudo avaliou a influência dos enxaguatórios bucais com lactato de cálcio e fluoreto de sódio na microdureza do esmalte e na permeabilidade da dentina durante o clareamento em consultório. Material e Métodos: Para avaliação da microdureza, blocos de esmalte foram submetidos aleatoriamente a diferentes tratamentos associados a agente clareador em consultório com peróxido de hidrogênio 40% (Opalescence Boost PF 40% / Ultradent; 3 sessões x 40 minutos cada) (n = 10): 1) Controle: aplicação de agente clareador; 2) Lactato de cálcio: imersão de 1 minuto antes do tratamento clareador; 3) Fluoreto de sódio: imersão por 1 minuto antes do tratamento clareador; 4) Lactato de cálcio + fluoreto de sódio: 1 minuto de imersão em solução de lactato de cálcio, seguido de 1 minuto de imersão em fluoreto de sódio antes do tratamento clareador. Os discos de dentina receberam os mesmos protocolos de tratamento (n = 10) para avaliar a permeabilidade. As avaliações da microdureza Knoop e da permeabilidade dentinária foram realizadas duas vezes (no início do estudo e 48 horas após o término do tratamento clareador). Resultados: O modelo linear generalizado considerando o delineamento de medidas repetidas ao longo do tempo mostrou que não houve diferença significativa entre os tratamentos (p = 0,9577) e entre as avaliações (p = 0,3267) em relação à microdureza Knoop. Os testes de Kruskal Wallis e Dunn mostraram que a imersão de lactato de cálcio antes do tratamento clareador proporcionou maior permeabilidade dentinária do que os outros grupos (p = 0,0009). Conclusão: O uso de fluoreto de sódio e lactato de cálcio associado ao clareamento em consultório não influenciou a microdureza do esmalte dentário, embora o lactato de cálcio possa aumentar a permeabilidade dentinária (AU)
Subject(s)
Sodium Fluoride , Tooth Bleaching , Calcarea Lactica , Dentin , Hardness TestsABSTRACT
【Objective】 To investigate the effects of oral calcium gluconate and calcium lactate granules on the changes of serum calcium(Ca2+ ) and parathyroid hormone (PTH) in first-time and regular apheresis platelet donors. 【Methods】 From July to November 2020, 84 first-time platelet donors and 35 regular blood donors were recruited for the study. The first-time donors, who were divided equally into two groups, each with 42 cases (28 males and 14 females), participated in two calcium experiments(each ≥14 days) with the regular donors. In the first experimental cycle, calcium gluconate oral solution (2 sticks of calcium gluconate for 180 mg of calcium supplement) was taken 20 min before donation; in the second experimental cycle, calcium lactate granules (2.5 g/bag for180 mg of calcium supplement) was taken 20 min before donation. Serum calcium and parathyroid hormone levels were measured before (20 min), starting (0 min), during (20, 40 min) blood collection. 【Results】 Total calcium levels in both first-time and regular donors began to decrease significantly at 20 min of collection and leveled off at 40 min of collection, while the overall PTH levels showed a rapid increase and then a slow decrease. Significant differences(P<0.01) were noticed for the comparison of changes in serum calcium before calcium supplementation in fixed and first-time donors; P<0.01 for the comparison of changes in Ca2+ and PTH at 20 min of collection versus before calcium supplementation; P<0.01 for the comparison of changes in Ca2+ and PTH at 40 min of collection versus the beginning of collection; and P<0.05 for the comparison of changes in Ca2+ in calcium in the two groups at 40 min of collection in first-time donors. For two calcium supplementation groups, significant differences(P<0.01) were noticed for comparison of changes in PTH at 20 min and 40 min of collection. The occurrence of toxic reactions to sodium citrate was similar in two calcium supplementation groups either donated regularly or for the first time. 【Conclusion】 For first-time apheresis donors, taking oral calcium gluconate solution 20 min before donation is more appropriate; for regular donors, taking calcium lactate flush is better, which could effectively stabilize the fluctuation of serum calcium and PTH during blood collection. and reduce the occurrence of hypocalcemia symptoms. This has a positive preventive effect on the reduction of toxic reactions to sodium citrate and minimize its incidence in blood donors.
ABSTRACT
OBJECTIVE:To establish HPLC method for the simultaneous determination of calcium lactate and calcium gluconate in compound calcium gluconate oral solution.METHODS:The test was performed on C 18 column with column tem?perature at25℃;the mobile phase was composed of0.025mol/L NaH 2 PO 4 (pH=2.50)with a flow rate of1.0ml/min and sam ple size of20?l;the detection wavelength was210nm.RESULTS:The calibration curves were linear over the range of0.719～46.040mmol/L(r=0.9999)for lactic acid and0.315～20.160mmol/L(r=0.9999)for gluconic acid.The average recovery rates of which were99.0%(RSD=1.65%)and100.5%(RSD=1.36%),respectively.CONCLUSION:This method is fast,simple,accurate,and it can be employed directly without isolation to determine the content of calcium lactate and calcium glu?conate simultaneously and to control the quality of compound calcium gluconate oral solution as well.