Research progress on natural antibacterial ingredients of glass ionomer cement / 口腔疾病防治

@#Glass ionomer cement (GIC) is widely used as a common filling material in dentistry but still exhibits problems with secondary caries and fractures. Thus, the antibacterial and anti-caries performance of GIC needs to be further improved. In recent years, natural antimicrobial components have become more desirable due to their good biological properties and low drug resistance. In this review, the natural antimicrobial ingredients in GIC modification are classified, reviewed and summarized according to the different sources of antimicrobial ingredients. In terms of animal origin, chitosan and casein phosphopeptide-amorphous calcium phosphate exhibit antimicrobial properties without affecting the mechanical properties of materials; propolis and bioactive enzymes have good biocompatibility; in terms of plant origin, polyphenols help improve the antimicrobial and mechanical properties of the material; arginine has a good remineralization effect; and plant essential oils have a certain ion release effect. In terms of microbial origin, antibiotics greatly improve the antibacterial properties of materials; in addition, the combined application of natural antimicrobial ingredients also exhibited excellent performance. Despite these advantages, the optimal addition concentration and biocompatibility in vivo are questions that need to be further explored before clinical applications can be achieved.

Effect of preconditioning the fractured coronal fragments with remineralizing agents on fracture resistance of re-attached teeth

Background: Fragment re-attachment has been considered as one of the treatment modalities for the management of fractured anterior teeth. Hydration of fractured fragments aids in inhibiting the loss of ions and maintains vitality and esthetics. Aim: The study aimed to evaluate the effect of preconditioning the fractured fragments with remineralizing agents on fracture resistance of re-attached teeth. Settings and Design: This was an in vitro study. Materials and Methods: Sixty freshly extracted noncarious human permanent maxillary central and lateral incisors were randomly allocated into three Groups of 20 each: Group 1: 2% sodium fluoride (2%NaF), Group 2: casein phosphopeptide–amorphous calcium phosphate (CPP-ACP), and Group 3: self-assembling peptide P11-4 (SAP). These were further divided into two subgroups of 10 teeth each, based on contact time with remineralizing agents, i.e., 30 min and 2 h. Fractured fragments were treated with remineralizing agents for a specified contact time and then re-attached with flowable composite resin. Force required to fracture the re-attached tooth was recorded in Newtons using universal testing machine. Statistical Analysis: Unpaired t-test, one-way analysis of variance test, and post hoc Tukey test were used for the statistical analysis. Results: A higher fracture resistance was noticed in fragments treated with 2% NaF (30 min- 215.6 N, 2 h- 188.5 N) compared to CPP-ACP (30 min- 141.3 N, 2 h- 111.1 N) and SAP (30 min- 134.8 N, 2 h- 149.5 N). At 30 min interval, it was found to be more in 2% NaF and CPP-ACP groups compared to 2 h. However, it increased with time in the SAP group. A statistically significant difference was found between the groups at both time intervals (P = 0.007 and 0.017). Conclusion: Preconditioning of fractured coronal fragments with 2% NaF showed higher fracture resistance compared to CPP-ACP and self-assembling peptide P11-4. Samples treated with SAP P11-4 exhibited good fracture resistance at 2 h contact time.

Casein phosphopeptide-amorphous calcium phosphate nanocomplex (CPP-ACP) in dentistry: state of the art / Nanocomplejo de fosfopéptido de caseína-fosfato de calcio amorfo (CPP-ACP) en Odontología: estado del arte

ABSTRACT Saliva and external agents containing different concentrations of sodium fluoride (NaF) promote the dental remineralization process. However, these resources may not be sufficient to counteract the multiple factors involved in the process of dental caries, especially in high-risk patients. There are alternatives that have been extensively researched, such as casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) which provides essential ions, like phosphate and calcium, acting as an adjuvant in the remineralization process. Manufacturers of CPP-ACP-based products also suggest that it can produce desensitizing effects. This nanocomplex has been used experimentally with some dental cements and adhesive systems, but it is important to clarify the effects of this procedure, and the remineralizing/desensitizing advantages it offers. The objective of this topic review was to present the state of the art on CPP-ACP nanocomplex. In terms of dental caries prevention, this remineralizing option is not better than NaF. CPP-ACP provides a dental desensitizing action, but it is temporary, similar or less effective than other alternatives such as potassium nitrate or NaF. The experimental incorporation of CPP-ACP into dental cements should be controlled for not to compromise the physico-chemical properties of the material. The use of dental products based on this nanocomplex as dental surface pretreatment may decrease the bond strength of adhesive materials, but this effect is material dependent.

RESUMEN La saliva y agentes externos que contienen diferentes concentraciones de fluoruro de sodio (NaF) favorecen el proceso de remineralización dental. No obstante, estos recursos podrían no ser suficientes para contrarrestar los múltiples factores involucrados en el proceso de caries dental, especialmente en pacientes con alto riesgo. Existen alternativas que han sido ampliamente investigadas, como el fosfopéptido de caseína-fosfato de calcio amorfo (CPP-ACP) que aporta iones esenciales como fosfato y calcio, actuando como coadyuvante en el proceso de remineralización. Los fabricantes de productos basados en CPP-ACP también sugieren que este es capaz de generar efectos desensibilizantes. Este nanocomplejo ha sido utilizado de forma experimental con algunos cementos dentales y sistemas adhesivos, pero es importante esclarecer los efectos de dicha incorporación y las ventajas remineralizantes/desensibilizantes que ofrece esta alternativa. El objetivo del presente artículo de revisión de tema consistió en presentar el estado del arte sobre el nanocomplejo CPP-ACP. En términos de prevención de caries dental, esta opción remineralizante no es superior al NaF. El nanocomplejo ejerce acción desensibilizante dental, pero esta es transitoria, similar o inferior a otras alternativas como nitrato de potasio o NaF. La incorporación experimental de CPP-ACP en cementos dentales debe ser controlada para no comprometer las propiedades fisicoquímicas del material. La utilización de productos dentales a base de este nanocomplejo como pretratamiento de la superficie dental puede disminuir la resistencia de unión de materiales adhesivos, pero este efecto es material-dependiente.

Effect of nonfluoridated remineralizing agents on initial enamel carious lesions: A systematic review

Background: Although fluoride enables remineralization, presence of calcium and phosphate ions is necessary to promote the process. So, various nonfluoridated remineralizing agents have been emerging to treat the noncavitated carious lesions. Aim: The aim of this systematic review was to assess the clinical effectiveness of nonfluoridated remineralizing agents on initial enamel carious lesions. Methods: Seven electronic databases were searched using the key words. In total, 158 human clinical trials were retrieved in the search from January 1950 to October 2016. Seventy-one repeated articles were excluded. Among the 87 articles obtained, 53 articles were eliminated after reading the title and abstracts. After assessing the full text, 28 articles were excluded. Three more studies were included from the cross references of the articles chosen. Results: All the nine trials included assessed the clinical effectiveness of casein phosphopeptide amorphous calcium phosphate (CPP ACP). They showed a positive effect of CPP ACP on the remineralization of white spot lesions. Conclusion: The use of CPP ACP resulted in significant reduction of the white spot lesion size measured using visual examination methods. This systematic review indicated a lack of reliable evidence supporting the clinical effectiveness of other commercially available nonfluoridated remineralizing agents.

Remineralizing potential of CPP-ACP in white spot lesions – A systematic review

The aim of this systematic review was to assess the long term remineralizing potential of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) only in paste form compared with fluoride varnish, and or placebo in both naturally occurring and post-orthodontic white spot lesions in vivo. Data Sources: The literature search covered the electronic databases: PubMed and Google scholar from 2005-2016. Only articles published in English were included. Randomized control trials in which CPP-ACP delivered by paste form were included. All studies which met inclusion criteria underwent two independent reviews. Study Selection: Two ninety five articles were identified from the search after excluding duplications. Abstracts of forty one articles were reviewed independently. Twenty nine articles were excluded after reading abstract. Full text articles were retrieved for fifteen relevant studies. After reviewing articles independently, three articles were excluded after full text reading. Finally twelve studies were selected based on the eligibility criteria. The remineralizing effect of CPP-ACP were compared with placebo and fluoridated toothpaste and fluoride varnish in randomized control trial. Conclusion: A high level evidence of remineralizing potential of CPP-ACP on naturally occurring white spot lesion and WSL post orthodontic treatment was found in comparison with placebo/fluoridated toothpaste and fluoride varnish without any statistically significant difference. Well-designed RCTs are, therefore, required to improve the level of evidence in this area.

Electronic probe analysis of enamel remineralization effect of casein phosphopeptide-amorphous calcium phosphate promoted by different concentrations of fluorine / 中华口腔医学杂志

Objective@#To evaluate the remineralization effect and mechanism of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) with different concentrations of fluorine on demineralized enamel using electronic probe.@*Methods@#Extracted premolar teeth for orthodontic purpose were immersed into lactic acid gel to prepare artificial white spot lesions (10 teeth in each group). Then the specimens were randomly assigned to three groups: Control group, with 5% of the CPP-ACP+deionized water; Group A with 5% CPP-ACP+500 mg/L F- and Group B with 5% CPP-ACP+900 mg/L F-. The teeth in each group were soaked in different solutions for 4 days and then were measured using electron probe tester. The changes of contents among the three groups were compared.@*Results@#No statistically significant difference in the percentage of fluorine was found in the control group before and after treatment (P=0.06), and the difference in the percentage of fluorine quality in the other two groups was statistically significant (P<0.05). Statistically significant difference was found between calcium oxide and phosphorus peroxide in the three groups before and after mineralization (P<0.05). The percentage change of fluorine mass in group B [(0.107±0.035)%] was significantly greater than that in group A [(0.057±0.038)%] (P<0.05), while fluorine mass in group A was significantly greater than that in control group [(0.013±0.019)%] (P<0.05). In group A and group B, the change in quality of calcium oxide and phosphorus peroxide was significantly greater than that in control group (P<0.05), while no significant difference was found between group A and group B (P>0.05).@*Conclusions@#The addition of fluorine in CPP-ACP increased the transport and penetration of calcium, phosphorus and fluorine on enamel surface.

Effect of CPP-ACP paste with and without CO2 laser irradiation on demineralized enamel microhardness and bracket shear bond strength

ABSTRACT Introduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected to a demineralization challenge using Streptococcus mutans. After demineralization, the samples were randomly divided into five equal experimental groups: Group 1 (control), the brackets were bonded without any surface treatment; Group 2, the enamel surfaces were treated with CPP-ACP paste for 4 minutes before bonding; Group 3, the teeth were irradiated with CO2 laser beams at a wavelength of 10.6 µm for 20 seconds. The samples in Groups 4 and 5 were treated with CO2 laser either before or through CPP-ACP application. SEM photomicrographs of a tooth from each group were taken to observe the enamel surface. The brackets were bonded to the buccal enamel using a conventional method. Shear bond strength of brackets and ARI scores were measured. Vickers microhardness was measured on the non-bonded enamel surface. Data were analyzed with ANOVA and Tukey test at the p< 0.05 level. Results: The mean shear bond strength and microhardness of the laser group were higher than those in the control group and this difference was statistically significant (p< 0.05). All groups showed a higher percentage of ARI score 4. Conclusion: CO2 laser at a wavelength of 10.6 µm significantly increased demineralized enamel microhardness and enhanced bonding to demineralized enamel.

RESUMO Introdução: muitos pacientes, ao buscar o tratamento ortodôntico, já apresentam lesões incipientes no esmalte e precisam ser submetidos a tratamentos preventivos. O objetivo do presente estudo in vitro foi avaliar o efeito da pasta CPP-ACP e da irradiação com laser de CO2 na microdureza do esmalte desmineralizado e na resistência ao cisalhamento de braquetes ortodônticos. Métodos: oitenta pré-molares humanos hígidos foram submetidos a desmineralização usando Streptococcus mutans. Após a desmineralização, as amostras foram divididas aleatoriamente em cinco grupos experimentais: Grupo 1 (controle), os braquetes foram colados sem qualquer tratamento de superfície; Grupo 2, a superfície do esmalte foi tratada com pasta CPP-ACP por 4 minutos antes da colagem; Grupo 3, os dentes foram irradiados com laser de CO2 no comprimento de onda de 10,6 µm, por 20 segundos; Grupos 4 e 5, as amostras foram tratadas com laser de CO2 antes ou durante a aplicação de CPP-ACP. Foram feitas fotomicrografias por Microscopia Eletrônica de Varredura (MEV) de um dente de cada grupo, para avaliação da superfície do esmalte. Os braquetes foram colados ao esmalte na face vestibular, usando-se o método convencional. Foram medidos a resistência ao cisalhamento dos braquetes e o escore do Índice de Adesivo Remanescente (ARI). A microdureza Vickers foi medida nas superfícies do esmalte onde não foi realizada colagem. Os dados foram analisados com ANOVA e teste Tukey ao nível de p< 0,05. Resultados: a média da força de resistência ao cisalhamento e da microdureza do grupo laser foi superior à do grupo controle, com diferença estatisticamente significativa (p < 0,05). Todos os grupos apresentaram maior porcentagem do escore ARI=4. Conclusões: o laser de CO2 no comprimento de onda de 10,6 µm aumentou significativamente a microdureza do esmalte desmineralizado e melhorou a adesão dos braquetes nele.

In situ effect of CPP-ACP chewing gum upon erosive enamel loss

Abstract Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPP-ACP on dental erosion. Objective This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase per group) of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI - Sugar free chewing gum with CPP-ACP; GII - Conventional sugar free chewing gum; and GIII - No chewing gum (control). Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day). After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (µm). Data were analyzed by Repeated-Measures ANOVA and Tukey's test (p<0.05). Results The use of chewing gum (CPP and No CPP) resulted in lower erosive enamel loss compared with the control group (p<0.05). CPP-ACP chewing gum (CPP) did not improve the protection against erosive enamel loss compared with conventional chewing gum (No CPP) (p>0.05). Conclusion The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.

Remineralization effect of casein phosphopeptide-amorphous calcium phosphate for enamel demineralization: a system review / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study  aims  to  assess  the  remineralization effect of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) on enamel demineralization by  performing  system review of  randomized  controlled  trials (RCT)  involving  the  treatment of enamel demineralization with  CPP-ACP.</p><p><b>METHODS</b>The  study  was  developed  based  on  the 
Cochrane handbook  for  systematic  reviews of  interventions (Version 5.1.0) and included  the  following: search  strategy, selection  criteria, data  extraction, and  risk  of  bias  assessment. We  searched electronic  databases  such  as  PubMed, Embase, Cochrane Library, CNKI, Wanfang and VIP up  to  September  2016. RCT of  treating  enamel demineralization with  CPP-ACP were  included. Data  extraction  and  domain-based  risk  of  bias  assessment  were independently  performed  by  two  reviewers.</p><p><b>RESULTS</b>Twelve  RCTs  were  included.  Because of the difference of experimental design and evaluation standards, the quantitative analysis can not be carried out.</p><p><b>CONCLUSIONS</b>There is no strong evidence that CPP-ACP is superior to conventional fluoride formulations in enamel remineralization. However, due  to the limitations of sample size, follow-up time and study design,  more high quality and large-sample RCT are needed to  further  verify  the evidence.</p>

Efeito in situ da utilização de uma goma de mascar com caseína fosfopeptídea fosfato de cálcio amorfo (CPP-ACP) previamente ao desafio erosivo inicial / Effect of CPP-ACP chewing gum previously to erosive demineralization

O efeito protetor da caseína fosfopeptídea fosfato de cálcio amorfo (CPP-ACP) contra a erosão dentária é controverso. Este estudo in situ teve como objetivo investigar a capacidade de uma goma de mascar com CPP-ACP em prevenir uma única desmineralização erosiva. Blocos de esmalte bovino (120) selecionados pela dureza superficial inicial foram divididos aleatoriamente entre os grupos: GI - goma de mascar com CPP-ACP, GII - goma de mascar sem CPP-ACP e GIII - controle negativo para avaliação do efeito protetor sem estimulação salivar (sem goma de mascar). Dezenove voluntários participaram do estudo durante três fases cruzadas de 2 h cada. Nas fases de GI e GII os voluntários usaram dispositivos intrabucais palatinos contendo 2 blocos de esmalte, durante 120 minutos e mascaram uma unidade da goma de mascar correspondente ao grupo nos últimos 30 minutos. No grupo controle os voluntários usaram o dispositivo intrabucal por 2h, sem uso de goma de mascar. Em cada fase, imediatamente após a utilização, os dispositivos intrabucais foram imersos em refrigerante tipo cola durante 5 minutos para promover a desmineralização erosiva. A dureza superficial final foi mensurada e os valores foram utilizados para o cálculo do percentual de perda de dureza. Os dados foram analisados por ANOVA de medidas repetidas e teste Tukey (α = 5%). Menor perda de dureza do esmalte foi encontrada após a utilização de goma de mascar com (GI - 32,7%) e sem (GII - 33,5%) CPP-ACP relação ao efeito salivar sem estimulação (GIII - 39,8%) (p <0,05). Não houve diferença entre GI e GII (p> 0,05). Os resultados sugerem que a utilização de goma de mascar imediatamente antes de uma desmineralização erosiva é capaz de diminuir a perda de dureza do esmalte. No entanto, a presença de CPP-ACP na goma de mascar não foi capaz de melhorar este efeito.

The erosion-protective effect of CPP-ACP is controversial. This in situ study aimed to investigate the ability of CPP-ACP chewing gum to prevent a single event of erosive demineralization. Bovine enamel blocks (120), after selection (initial surface hardness) were randomly assigned to groups: GI-chewing gum with CPP-ACP, GIIchewing gum without CPP-ACP and Control group-salivary effect without stimulation (no gum). Nineteen volunteers participated on this study during 3 crossover phases of 2 h. On GI and GII, the volunteers wore intraoral palatal devices for 120 min and chewed a unit of the corresponding chewing gum on the last 30 min. On Control group the volunteer wore the appliance for 2 h, without chewing gum. On each phase immediately after the intraoral use, devices were extra orally immersed in cola drink for 5 minutes to promote erosive demineralization. The percentage of surface hardness loss was calculated. The data were analyzed by Repeated Measures ANOVA and Turkeys test. Less enamel hardness loss was found after the use of chewing gum with (GI-32.7 %) and without (GII-33.5%) CPP-ACP when compared to salivary effect without stimulation (control- 39.8%) (p<0.05). There was no difference between GI and GII (p>0.05). The results suggest that the use of chewing gum immediately before an erosive demineralization is able to diminish the enamel hardness loss. However, the presence of CPP-ACP in the chewing gum cannot enhance this protective effect.

Efeito in situ da utilização de uma goma de mascar com caseína fosfopeptídea fosfato de cálcio amorfo (CPP-ACP) previamente ao desafio erosivo inicial / Effect of CPP-ACP chewing gum previously to erosive demineralization

O efeito protetor da caseína fosfopeptídea fosfato de cálcio amorfo (CPP-ACP) contra a erosão dentária é controverso. Este estudo in situ teve como objetivo investigar a capacidade de uma goma de mascar com CPP-ACP em prevenir uma única desmineralização erosiva. Blocos de esmalte bovino (120) selecionados pela dureza superficial inicial foram divididos aleatoriamente entre os grupos: GI - goma de mascar com CPP-ACP, GII - goma de mascar sem CPP-ACP e GIII - controle negativo para avaliação do efeito protetor sem estimulação salivar (sem goma de mascar). Dezenove voluntários participaram do estudo durante três fases cruzadas de 2 h cada. Nas fases de GI e GII os voluntários usaram dispositivos intrabucais palatinos contendo 2 blocos de esmalte, durante 120 minutos e mascaram uma unidade da goma de mascar correspondente ao grupo nos últimos 30 minutos. No grupo controle os voluntários usaram o dispositivo intrabucal por 2h, sem uso de goma de mascar. Em cada fase, imediatamente após a utilização, os dispositivos intrabucais foram imersos em refrigerante tipo cola durante 5 minutos para promover a desmineralização erosiva. A dureza superficial final foi mensurada e os valores foram utilizados para o cálculo do percentual de perda de dureza. Os dados foram analisados por ANOVA de medidas repetidas e teste Tukey (α = 5%). Menor perda de dureza do esmalte foi encontrada após a utilização de goma de mascar com (GI - 32,7%) e sem (GII - 33,5%) CPP-ACP relação ao efeito salivar sem estimulação (GIII - 39,8%) (p <0,05). Não houve diferença entre GI e GII (p> 0,05). Os resultados sugerem que a utilização de goma de mascar imediatamente antes de uma desmineralização erosiva é capaz de diminuir a perda de dureza do esmalte. No entanto, a presença de CPP-ACP na goma de mascar não foi capaz de melhorar este efeito...

The erosion-protective effect of CPP-ACP is controversial. This in situ study aimed to investigate the ability of CPP-ACP chewing gum to prevent a single event of erosive demineralization. Bovine enamel blocks (120), after selection (initial surface hardness) were randomly assigned to groups: GI-chewing gum with CPP-ACP, GIIchewing gum without CPP-ACP and Control group-salivary effect without stimulation (no gum). Nineteen volunteers participated on this study during 3 crossover phases of 2 h. On GI and GII, the volunteers wore intraoral palatal devices for 120 min and chewed a unit of the corresponding chewing gum on the last 30 min. On Control group the volunteer wore the appliance for 2 h, without chewing gum. On each phase immediately after the intraoral use, devices were extra orally immersed in cola drink for 5 minutes to promote erosive demineralization. The percentage of surface hardness loss was calculated. The data were analyzed by Repeated Measures ANOVA and Turkeys test. Less enamel hardness loss was found after the use of chewing gum with (GI-32.7 %) and without (GII-33.5%) CPP-ACP when compared to salivary effect without stimulation (control- 39.8%) (p<0.05). There was no difference between GI and GII (p>0.05). The results suggest that the use of chewing gum immediately before an erosive demineralization is able to diminish the enamel hardness loss. However, the presence of CPP-ACP in the chewing gum cannot enhance this protective effect...

Comparative evaluation of remineralization potential of casein phosphopeptide-amorphous calcium phosphate and casein phosphopeptide-amorphous calcium phosphate fluoride on artificial enamel white spot lesion: An in vitro light fluorescence study.

Background: World-wide, the contribution of dental caries to the burden of oral diseases is about 10 times higher than that of periodontal disease, the other common oral condition. Owing to its globally high prevalence, dental caries is a "pandemic" disease characterized by a high percentage of untreated carious cavities causing pain, discomfort and functional limitations. Untreated carious cavities; furthermore, have a significant impact on the general health of children and on the social and economic well-being of communities. A surgical approach to the elimination of carious lesion was developed a century ago; this approach was necessary at that time, because there was no valid alternative. The focus in caries has recently shifted to the development of methodologies for the detection of the early stages of caries lesions and the non-invasive treatment of these lesions. The non-invasive treatment of early lesions by remineralization has the potential to be a major advance in the clinical management of the disease. Remineralization of white-spot lesions may be possible with a variety of currently available agents containing fluoride, bioavailable calcium and phosphate and phosphate. This concept bridges the traditional gap between prevention and surgical procedures, which is just what dentistry needs today. Aims and Objectives: The aim of this in vitro study was to evaluate and to compare the remineralization potential of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP) on artificial white spot enamel lesions using the quantitative light fluorescence (QLF). Materials and Methods: A total of 45 caries-free extracted maxillary first premolars were embedded in acrylic resin. The samples were randomly divided into three groups namely control group, CPP-ACP group and CPP-ACFP group with 15 samples in each group. The samples of each group were subjected to demineralization process for a period of 96 h. The samples were then mounted in the artificial mouth model and subjected to remineralization and pH cycling for a period of 21 days. QLF readings were recorded at the end of demineralization (1 st , 7 th , 14 th and 21 st day) and were statistically analyzed. Results: As compared with artificial saliva both CPP-ACP and CPP-ACFP produced significant amount of remineralization of the artificial enamel white spot lesion (P < 0.001), however when the remineralizing effect of CPP-ACP was compared with the remineralizing effect of CPP-ACFP there was no significant difference. Significant amount of remineralization was produced by CPP-ACP and CPP-ACFP only after the 7 th day. After the 14 th day, the remineralization produced by both CPP-ACP and CPP-ACFP as compared to artificial saliva was non-significant.

Impact of Experimental Nano-HAP Pastes on Bovine Enamel and Dentin Submitted to a pH Cycling Model

This in vitro study evaluated the preventive potential of experimental pastes containing 10% and 20% hydroxyapatite nanoparticles (Nano-HAP), with or without fluoride, on dental demineralization. Bovine enamel (n=15) and root dentin (n=15) specimens were divided into 9 groups according to their surface hardness: control (without treatment), 20 Nanop paste (20% HAP), 20 Nanop paste plus (20% HAP + 0.2% NaF), 10 Nanop paste (10% HAP), 10 Nanop paste plus (10% HAP + 0.2% NaF), placebo paste (without fluoride and HAP), fluoride paste (0.2% NaF), MI paste (CPP-ACP, casein phosphopeptide-amorphous calcium phosphate), and MI paste plus (CPP-ACP + 0.2% NaF). Both MI pastes were included as commercial control products containing calcium phosphate. The specimens were treated with the pastes twice a day (1 min), before and after demineralization. The specimens were subjected to a pH-cycling model (demineralization–6-8 h/ remineralization-16-18 h a day) for 7 days. The dental subsurface demineralization was analyzed using cross-sectional hardness (kgf/mm 2 , depth 10-220 µm). Data were tested using repeated-measures two-way ANOVA and Bonferroni's test (p<0.05). The only treatment able to reduce the loss of enamel and dentin subsurface hardness was fluoride paste (0.2% NaF), which differed significantly from the control at 30- and 50-µm depth (p<0.0001). The other treatments were not different from each other or compared with the control. The experimental Nanop pastes, regardless of the addition of fluoride, were unable to reduce dental demineralization in vitro.

Este estudo in vitro avaliou o potencial de pastas experimentais contendo nanopartículas de hidroxiapatita a 10% e 20% (Nano-HAP), com ou sem fluoreto, na prevenção da desmineralização dentária. Espécimes de esmalte (n=15) e de dentina radicular (n=15) bovinos foram divididos em nove grupos de acordo com o valor de dureza superficial: controle (sem tratamento), pasta Nanop 20 (HAP 20%), pasta Nanop 20 plus (HAP 20% + NaF 0,2%), pasta Nanop 10 (HAP 10%), pasta Nanop 10 plus (HAP 10% + NaF 0,2%), pasta placebo (sem F e HAP), pasta fluoretada (NaF 0,2%), pasta MI (CPP-ACP, fosfopeptídio da caseína-fosfato de cálcio amorfo), e pasta MI plus (CPP-ACP + NaF 0,2%). As duas pastas MI foram inclusas como grupos controles comerciais contendo fosfato de cálcio. Os espécimes foram tratados com as pastas duas vezes ao dia (1 min), antes e após a desmineralização. Os espécimes foram submetidos a um modelo de ciclagem de pH (desmineralização 6-8 h/ remineralização 16-18 h por dia) durante sete dias. A desmineralização dentária de subsuperfície foi avaliada através da dureza longitudinal (kgf/mm 2 , profundidade de 10-220 µm). Os dados foram analisados utilizando ANOVA a dois critérios e teste de Bonferroni (p<0,05). O único tratamento capaz de reduzir a perda da dureza de subsuperfície do esmalte e da dentina foi a pasta fluoretada (NaF 0,2%), a qual diferiu significativamente do controle nas profundidades de 30 e 50 µm da superfície (p<0,0001). Os outros tratamentos não foram diferentes entre si ou quando comparados ao controle. As pastas experimentais Nanop, independentemente da presença de fluoreto, não foram capazes de reduzir a desmineralização dentária in vitro.

Quantitative microradiographic analysis of remineralization of enamel lesions promoted by casein phosphopeptide amorphous calcium phosphate and fluoride / 吉林大学学报(医学版)

Objective To evaluate the remineralization effect of casein phosphopeptide amorphous calcium phosphate(CPP-ACP) and fluoride complex on artificial enamel subsurface white spot lesions in vitro in order to provide a new method to treat the postorthodontic enamel demineralization.Methods Extracted premolar teeth for orthodontic reason were immersed into lactic acid gel to prepare artificial white spot lesions.Then the specimens were randomly assigned to seven groups:5.0%CPP-ACFP group,1.0% CPP-ACP group,0.1% CPP-ACPgroup,calcium phosphate saturated solution group,calcium phosphate saturated solution plus fluorid group,deionized water group.Lesion depths and mineral loss were quantitatively determined by microradiography in various groups.Results The lesion depths and mineral loss after remineralization in each group were significantly reduced(P0.05),but the lesion depths and mineral loss in these three groups were significantly lower than those in deionized water group(P