Combined effect of Er,Cr:YSGG laser and casein phosphopeptide amorphous calcium phosphate on the prevention of enamel demineralization:: An in-vitro study

ObjectivesTo compare the effect of use of laser, casein phosphopeptide–amorphous calcium phosphate (CPP–ACP), and their combination on prevention of enamel demineralization using polarized light microscopy to assess lesion depth.Materials and MethodsEighty premolars were randomly allocated to four equal groups (n = 20): Group I: Control group, no preventive measures. Group II: CPP–ACP. Group III: Er,Cr:YSGG laser. Group IV: Er,Cr:YSGG laser followed by CPP–ACP. Specimens were subjected to thermocycling and brushing protocols equivalent to 1 year intraorally. Then, all teeth were subjected to acid challenge. Teeth were then sectioned longitudinally and examined under a polarized light microscope and lesion depth was measured.ResultsGroup IV resulted in the least lesion depth with a significant difference between it and all other groups. CPP–ACP alone and laser alone also showed a significant difference in white spot lesion (WSL) depth compared to the control group; however, no significant difference was found between them.ConclusionsThe combined use of laser and CPP–ACP showed the best prevention against WSL development. The use of CPP–ACP or laser alone also resulted in a significant reduction in lesion depth but was significantly less than their combined use, with no significant difference between them.     

酪蛋白磷酸肽钙磷复合体对黏性放线菌黏附影响的实验研究

目的：研究酪蛋白磷酸肽钙磷复合体（casein phosphopeptide-amorphic calcium phosphate,CPP-ACP）对黏性放线菌黏附的影响,进一步探讨CPP-ACP的防龋机制。方法：采用唾液包被的羟磷灰石（saliva-coated hydroxyapatite,S-HA）形成实验性膜的体外黏附实验模型,用不同浓度（0.5%～5.0%（W/V））CPP-ACP处理S-HA,定量观察黏性放线菌在S-HA上的黏附情况。结果：黏性放线菌对经各实验浓度的CPP-ACP处理后的S-HA黏附能力明显下降,黏附量（CPM）随CPP-ACP浓度的升高而降低,且黏附抑制率均达100%。结论：CPP-ACP对黏性放线菌在S-HA上的黏附具有抑制作用,随CPP-ACP浓度的升高其抑制作用增强。     

The effect of CPP-ACP on enamel wear under severe erosive conditions

Objective

In addition to its role as a remineralizing agent in preventing dental caries, recent evidence has shown that casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) can protect teeth against erosion. The aim of this study was to determine whether CPP-ACP could reduce enamel wear rates under severe erosive conditions simulating heavy attrition and gastric regurgitation.

Design

Enamel specimens were subjected to 10,000 wear cycles at a load of 100 N and pH 1.2 in a tooth wear machine. The machine was stopped every 2 min (160 cycles), and CPP-ACP in the form of a paste was applied for 5 min in experimental group 1. A paste with the same formulation but without CPP-ACP was applied in experimental group 2. No paste was applied in the control group.

Results

A linear mixed model analysis indicated that the mean wear rates in experimental group 1 (0.44 ± 0.05 mm³ per 1000 cycles) and in experimental group 2 (0.63 ± 0.06 mm³ per 1000 cycles) were significantly lower than that in the control group (0.92 ± 0.11 mm³ per 1000 cycles) (p < 0.05). The mean wear rate in experimental group 1 was also lower than that in experimental group 2 (p < 0.05). Wear facets in experimental groups 1 and 2 were noted to be smoother and more polished than those in the control group.

Conclusions

Both remineralizing and lubricating properties of the paste containing CPP-ACP appear to contribute to wear reduction in enamel. These findings may lead to new strategies for the clinical management of tooth wear.     

光学相干断层成像检测牙釉质表层脱矿与再矿化的实验研究

目的利用光学相干断层成像技术(OCT)观察不同制剂对年轻恒牙釉脱矿和再矿化效果的影响。方法 将正畸拔除的年轻恒前磨牙制成60个釉质块,随机均分为4组。每天进行如下处理:A组蒸馏水湿敷30min;B组含氟牙膏湿敷30min;C组护牙素湿敷30min;D组多乐氟湿敷30min,置于脱矿液1.5h,最后置于人工唾液中22h。每个步骤间用去离子水冲洗实验样品。实验周期重复30天。在处理前和第 7、15、30天,使用扫频光源OCT完成对样本的扫描和成像,同时使用显微硬度计测量各样本表面的显微硬度。结果 釉质脱矿深度:7天后,A组与其他各组相互比较,差异有统计学意义( P <0.05),B、C、D组组间比较差异无统计学意义( P >0.05)。30天后,C组和D组比较,差异无统计学意义( P >0.05),其余各组之间两两比较,差异均有统计学意义( P <0.05)。显微硬度测量:30天后,各处理组较处理前显微硬度值降低,A组显微硬度值最低,C组与D组显微硬度值高于B组,且差异有统计学意义( P <0.05)。C组和D组间釉质块显微硬度值差异无统计学意义( P >0.05)。结论 OCT可以较准确的显示釉质脱矿部位,在早期龋的诊断方面具有临床意义。护牙素和多乐氟均能有效的抑制牙釉质表面脱矿。     

Resin bonding using an all-etch or self-etch adhesive to enamel after carbamide peroxide and/or CPP-ACP treatment

BACKGROUND: Limited evidence exists regarding the effect of carbamide peroxide and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on composite-enamel bonding. Microshear bond strengths, using either a total-etch or self-etching adhesive, to enamel treated with carbamide peroxide and/or CPP-ACP were investigated. MATERIALS AND METHODS: Twenty-six extracted human third molars were sectioned into four parts, each being allocated into one of the four groups (n=26): bleach (Polanight, 16% carbamide peroxide), CPP-ACP (GC Tooth Mousse), bleach and then CPP-ACP, or untreated (control). The surfaces were bonded with a total-etch bonding system (Single Bond) or a self-etching primer system (Clearfil SE Bond) and tested using a microshear test. RESULTS: A significant difference in bond strength was found between bonding systems. SE Bond showed the highest bond strength to untreated enamel (p < 0.05). The microshear bond strength of SE Bond decreased when the enamel was treated with carbamide peroxide, CPP-ACP or both (p < 0.05). Only combined use of carbamide peroxide and CPP-ACP significantly affected microshear bond strength with Single Bond. CONCLUSION: These findings suggest the shear bond strength of resin to enamel using a self-etching priming adhesive may be affected if the enamel is treated with a bleaching agent or CPP-ACP.     

Effects of different pre-treatment methods on the shear bond strength of orthodontic brackets to demineralized enamel

Objective. To compare the effects of different treatment methods used for the enamel damage, on the shear bond strength (SBS) and fracture mode of orthodontic brackets. Materials and methods. Freshly-extracted 140 premolars were randomly allocated to seven groups: Group I was considered as the control of other groups. The remaining groups were exposed to demineralization. In group II, brackets were directly bonded to the demineralized enamel surface. CPP-ACP paste (GC Tooth Mousse), fluoride varnish (Bifluorid 12), microabrasion with a mixture prepared with 18% hydrochloric acid and fine pumice powder, microabrasion with an agent (Opalustre) and resin infiltrant (Icon®) were applied in Groups III, IV, V, VI and VII, respectively. The specimens were tested for SBS and bond failures were scored according to the Adhesive Remnant Index (ARI). Analysis of variance and Tukey tests were used to compare the SBS of the groups. ARI scores were compared with G-test. The statistical significance was set at p < 0.05 level. Results. Statistically significant differences were found among seven groups (F = 191.697; p < 0.001). The SBSs of groups I (mean = 18.8 ± 2.0 MPa) and VII (mean = 19.1 ± 1.4 MPa) were significantly higher than the other groups. No statistically significant difference was found between groups IV (mean = 11.5 ± 1.2 MPa) and V (mean = 12.6 ± 1.5 MPa). The differences in ARI scores of the groups were statistically significant (p < 0.01). Conclusions. All demineralization treatment methods improve bonding to demineralized enamel. Resin infiltrant application after demineralization showed similar bond strength values as intact enamel.     

Comparison of the remineralization potential of CPP-ACP and CPP-ACP with 900 ppm fluoride on eroded human enamel: An in situ study

Objective

The aim of this in situ study was to compare the remineralization potential of pastes containing CPP-ACP and CPP-ACP with 900 ppm fluoride on human enamel softened by a cola drink.

Design

Forty-five enamel specimens obtained from human third molar teeth were eroded in a cola drink for 8 min and then attached to intra-oral devices worn by five volunteers. The specimens were subjected to three different in situ remineralization protocols using: (1) CPP-ACP (Group I), (2) CPP-ACP with 900 ppm fluoride (Group II), and (3) saliva (Group III, control). Vickers microhardness measurements were obtained at baseline followed by demineralization and remineralization stages.

Results

The CPP-ACP, CPP-ACP with 900 ppm fluoride and saliva controls resulted in 46.24%, 64.25% and 2.98% increase in post-erosion microhardness values, respectively. One-way ANOVA revealed statistically significant differences in the mean microhardness values between pastes containing CPP-ACP and CPP-ACP with 900 ppm fluoride.

Conclusions

Both CPP-ACP and CPP-ACP with 900 ppm fluoride substantially remineralized the softened enamel, with the CPP-ACP and fluoride combination showing higher remineralization potential than CPP-ACP. This study confirmed the synergistic effect of fluoride with CPP-ACP on remineralization of eroded enamel.     

Effect of CPP-ACP addition on physical properties of zinc oxide non-eugenol temporary cements

Objectives

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is a milk derivative which holds nanoclusters of calcium and phosphate ions. The presence of CPP-ACP has been found to reduce demineralization and enhance remineralization in subsurface enamel and in dentin. Incorporation of CPP-ACP into luting cements has not been investigated. The aim of this study was to determine the effect on the physical properties of two commercially available zinc oxide non-eugenol temporary luting cements with incorporation of up to 8% (w/w) CPP-ACP.

Methods

Setting time, compressive strength, diametral tensile strength, film thickness and solubility tests were investigated for 0, 0.5, 1.0, 2.0, 3.0, 4.0 and 8.0% (w/w) CPP-ACP incorporated into Freegenol™ and Temp-Bond^® NE. Tests were carried out based on ISO 3107 requirements.

Results

Compressive and diametral tensile strengths progressively decreased with increasing concentrations of up to 8.0% (w/w) CPP-ACP incorporated into both Freegenol™ and Temp-Bond^® NE. Setting time was delayed beyond ISO requirements. Film thickness was not adversely affected. Increased solubility of Temp-Bond^® NE with 8.0% (w/w) CPP-ACP incorporation suggested an effect of the CPP-ACP on this property for this cement.

Significance

The incorporation of up to 8.0% (w/w) CPP-ACP into two zinc oxide non-eugenol luting cements has no adverse effects on the film thickness, compressive strength and diametral tensile strength of the cements investigated. Solubility investigations suggest that CPP-ACP leaches out of the zinc oxide non-eugenol luting cements into an aqueous environment.     

Can demineralized enamel surfaces be bonded safely?

Objective. To evaluate and compare the effects of enamel demineralization, microabrasion therapy and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application on the shear bond strength (SBS) of orthodontic brackets bonded to enamel surfaces and enamel color. Materials and methods. Eighty freshly extracted human maxillary premolar teeth were allocated to one of the four groups. Brackets were bonded directly to non-demineralized enamel surfaces in Group I (control group), directly to the demineralized enamel surfaces in Group II, to demineralized enamel surfaces after CPP-ACP application in Group III and to demineralized enamel surfaces after microabrasion therapy in Group IV. The samples were stored in water for 24 h at 37°C and then underwent thermocycling. The SBS in megapascals (MPa) was determined by a shear test with 0.5 mm/min crosshead speed and failure types were classified with modified adhesive remnant index scores. The data were analyzed with one-way analyses of variance (ANOVA), Tukey and chi-square tests at the α = 0.05 level. Results. Significant differences were found among the four groups (F = 21.57, p < 0.01). No significant difference was found between Group I and III (17.12 ± 2.84 and 15.08 ± 3.42 MPa, respectively) or between Group III and IV (12.82 ± 2.64 MPa). The lowest SBS value was determined in Group II (5.88 ± 2.12 MPa). Enamel demineralization, microabrasion therapy and CPP-ACP application affected enamel color significantly. Conclusion. CPP-ACP application and microabrasion therapy are able to increase the decreased SBS of orthodontic brackets because of enamel demineralization.     

Calcium phosphate‐based remineralization systems: scientific evidence?

Dental caries remains a major public health problem in most communities even though the prevalence of disease has decreased since the introduction of fluorides. The focus in caries research 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. Topical fluoride ions, in the presence of calcium and phosphate ions, promote the formation of fluorapatite in tooth enamel by a process referred to as remineralization. The non-invasive treatment of early caries lesions by remineralization has the potential to be a major advance in the clinical management of the disease. However, for net remineralization to occur adequate levels of calcium and phosphate ions must be available and this process is normally calcium phosphate limited. In recent times three calcium phosphate-based remineralization systems have been developed and are now commercially available: a casein phosphopeptide stabilized amorphous calcium phosphate (Recaldent (CPP-ACP), CASRN691364-49-5), an unstabilized amorphous calcium phosphate (ACP or Enamelon) and a bioactive glass containing calcium sodium phosphosilicate (NovaMin). The purpose of this review was to determine the scientific evidence to support a role for these remineralization systems in the non-invasive treatment of early caries lesions. The review has revealed that there is evidence for an anticariogenic efficacy of the Enamelon technology for root caries and for the Recaldent technology in significantly slowing the progression of coronal caries and promoting the regression of lesions in randomized, controlled clinical trials. Hence the calcium phosphate-based remineralization technologies show promise as adjunctive treatments to fluoride therapy in the non-invasive management of early caries lesions.