Potential agents to control enamel caries-like lesions

Effect of air-abrasion pretreatment with three desensitizing agents on efficacy of in-office tooth bleaching

OBJECTIVE

To evaluate the influence of air-abrasion of enamel with three different desensitizing powders on the whitening effect of a bleaching gel containing 40% H2O2, which was used for in-office tooth bleaching.

MATERIALS AND METHODS

Forty human incisors, extracted and prepared, were acquired for this study and subsequently randomized into four groups (n = 10). The control group specimens underwent no pretreatment prior to the bleaching procedure, whereas the remaining three groups underwent air abrasion using distinct desensitizing powders; (a) Sylc, which contains bioglass 45S5; (b) BioMinF, which contains calcium phospho-fluoro-silicate glass; and (c) MI Pearls, which contains nano-hydroxyapatite, 1 h preceding the Opalescence Boost PF 40% bleaching procedure. Color measurements were conducted using a double-beam UV-Vis spectrophotometer at four distinct time points (prior to bleaching, 24 h, 15 days, and 30 days post-bleaching).

RESULTS

Tooth color change outcomes revealed that there were no statistically significant results with respect to the interaction of the two criteria (treatments and time) (p = 0.990). Additionally, there were no statistically significant results with respect to the main effects of treatments (p = 0.385), while there were statistically significant effects with respect to the time criterion (p = 0.013).

CONCLUSIONS

The use of the tested desensitizing powders prior the bleaching procedure did not affect the tooth color change induced by the tested bleaching agent.

CLINICAL SIGNIFICANCE

Tooth color change and whiteness are not affected by air-abrasion desensitizing treatments when applied prior to in-office bleaching procedures.

Dentine surface modification and remineralization induced by bioactive toothpastes

OBJECTIVE

In this study, dentine surface was analysed through Environmental-scanning-electron-microscopy (ESEM) with energy-dispersive-X-ray-spectrometry (EDX) and Fourier-transform-infrared-spectroscopy (FTIR) with attenuated total-reflectance (ATR) to assess the morpho-chemical changes and variations in mineralization degree after demineralizing treatment, after five toothpastes application (HA & Citrate toothpaste, Zinc-HA toothpaste, Calcium Sodium Phosphosilicate toothpaste, Arginine & Calcium carbonate toothpaste, Colgate-Triple-Action, and Control toothpaste), after soaking in artificial saliva and after citric acid attack.

METHODS

Ca/P, Ca/N and P/N ratios were calculated from EDX atomic data to evaluate the mineralization degree of dentine surface. The IR calcium phosphate (CaP)/collagen and carbonate/collagen ratios has been evaluated to assess the remineralization changes in dentine; the carbonate/collagen IR ratio was calculated to identify the nucleation of B-type-carbonated apatite and calcium carbonate.

RESULTS

ESEM-EDX and ATR-FTIR showed residuals of toothpastes after the treatments in all cases, with a general increase in the mineralization degree after soaking in artificial saliva and a decrease after acid attack. Treatment with Arginine & Calcium carbonate toothpaste showed the highest Ca/P value after treatment (Ca/P 1.62) and acid attack (Ca/P 1.5) in confirmation, IR showed the highest amount of carbonate after treatment and soaking in artificial saliva. Arginine and calcium carbonate toothpaste and HA and citrate toothpaste remained to a higher extent on the dentine surface and revealed a higher remineralization activity. These formulations showed higher resistance to demineralization attack, as demonstrated by a higher ICaP/IAmide II intensity ratio than those obtained after EDTA treatment.

CONCLUSIONS

Toothpastes that remained to a higher extent on dentine surface (arginine and calcium carbonate toothpaste in particular) were more able to promote remineralization. The formed calcium phosphate (CaPs) phase was intimately bound to dentine rather than a simple deposit.

Effect of N-Acetylcysteine on initial Carious Enamel Lesions in primary teeth: an In-vitro study

BACKGROUND

Dental caries initiates with non-cavitated enamel lesions as the first stage. The cariogenic potential of N-Acetylcysteine (NAC) may be due to its usage frequency and form. This study aimed to evaluate the impact of exposure time of NAC on initial enamel caries-like lesions in primary teeth by assessing the morphological alteration using a scanning electron microscope (SEM) and mineral content using energy dispersive x-ray spectroscopy (EDX).

METHODS

Forty primary incisor teeth were randomly divided into 4 groups S, S1, S2, and S3 (10 specimens/group). Teeth crowns were cut from their roots and inserted into an acrylic mold with its buccal surface directed upward. Centrally isolated enamel window (2 × 2 mm) on the tooth was done. Ten specimens were selected to evaluate normal enamel while the remaining thirty specimens were immersed in demineralizing solution for 96 h to produce enamel caries-like lesions. PH cycling was performed by immersing each tooth sample in 20 mL of demineralizing solution for 3 h then, preserved for the remaining day hours in 10 ml of artificial saliva interspersed with treatments applications with 10 ml NAC for 10 min twice a day for one- or three-months different treatment modalities. Thermocycling was done for all specimens then they were subjected to SEM and EDX analysis. ANOVA and Bonferroni post hoc tests were utilized in data analysis.

RESULTS

In teeth treated by NAC for 3 months (group-S3), SEM images showed severe loss of enamel architecture with large NAC deposits detected. A meaningful difference was observed among different groups concerning calcium, phosphorus, fluoride, ca/P ratio, carbon, nitrogen, and oxygen contents (P < 0.05).

CONCLUSION

NAC had a detrimental impact on enamel caries-like lesions in human primary teeth.

Resin-modified glass ionomer enriched with BIOGLASS: Ion-release, bioactivity and antibacterial effect

Developing dental materials for the prevention of remineralization or demineralization is important for high-risk caries patients. This study aimed to evaluate the physicochemical and microbiological effects of adding 45S5 bioglass to resin-modified glass ionomer cement (RMGIC). Samples belonged to the following groups: GIC: conventional glass ionomer cement (Vitro Fil), RMGIC: resin-modified GIC (Vitro Fil LC), and RMGIC/45S5: RMGIC with 10% (wt %) of 45S5. Changes in pH and release of fluoride, calcium, and phosphorus ions under acidic (pH 4) and neutral (pH 7) pH conditions were evaluated. Antibacterial activity was verified based on colony-forming units. Material sorption and solubility were analyzed after bacterial exposure. After 28 days, the bioactivity of the materials was evaluated using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Analysis of variance, post hoc Scheffe, and Tukey (α = 0.05) tests were employed for statistical analysis. RMGIC/45S5 showed higher alkalization activity, calcium release at pH 4 and 7, and sorption than GIC and RMGIC (p < .05). Release of phosphorus and fluoride at pH 4 and 7 was higher for GIC than that for RMGIC and RMGIC/45S5 (p < .05). RMGIC/45S5 showed higher values than RMGIC (p < .05). However, antibacterial activity did not differ among the groups. Precipitates of calcium and phosphorus were visualized in RMGIC/45S5 samples via SEM/EDS. These results indicate that the RMGIC/45S5 promotes alkalization and increases the release of calcium, phosphorus, and fluoride ions, resulting in precipitate deposition rich in calcium and phosphorus, thereby being a promising option to improve the bioactivity of RMGIC.

Effect of self-assembling peptide and other remineralizing agents on preventing initial enamel lesions around orthodontic brackets: An in vitro comparative study

OBJECTIVE

To investigate and compare the effect of self-assembling peptide SAP (P_11-4), casein phosphopeptide-amorphous calcium phosphate fluoride paste (CPP-ACPF), and fluoride varnish (FV) on preventing enamel demineralization around orthodontic brackets.

MATERIAL AND METHODS

Orthodontic brackets were bonded to the buccal surfaces of 80 freshly extracted human maxillary premolars. Teeth were randomly assigned to four groups (n=20) according to the remineralizing agent used as follows: SAP (P_11-4) group (Curodont™ Protect/Credentis), CPP-ACPF group (MI Paste Plus®/Recaldent™), fluoride varnish group (Profluoride varnish®/VOCO), and control group. All products were applied according to the manufacturer's instructions. Specimens were cycled in daily refreshed demineralizing and remineralizing solutions for 8h and 16h, respectively, for 28 days. The calcium/phosphorus ratio (Ca/P) and surface microhardness (SMH) were evaluated at baseline and at two and four weeks. Two-way ANOVA (analysis of variance), one-way ANOVA and repeated measures ANOVA were used for statistical analysis.

RESULTS

Two-way ANOVA demonstrated significant differences between remineralizing agents and time points. After 4 weeks, the SAP (P_11-4) group had had significantly higher Ca/P ratio and SMH (1.68±0.11 and 346.47±55.38) compared to other groups, followed by CPP-ACPF (1.52±0.19 and 283.53±64.75), FV (1.37±0.14 and 262.80±82.98), and the control group (1.31±0.10 and 213.00±41.95). Significantly higher Ca/P ratio and SMH were observed at 2 weeks in the control group (1.44±0.10 and 269.63±57.37) and FV group (1.52±0.09 and 321.17±55.24) compared to 4 weeks. No significant differences were found regarding Ca/P ratio and SMH at 2 weeks in the CPP-ACPF (1.55±0.15 and 295.14±53.88) and SAP P_11-4 groups (1.64±0.10 and 320.18±58.04) compared to 4 weeks.

CONCLUSION

SAP (P_11-4) had the greatest remineralizing efficacy compared to FV and CPP-ACPF. Moreover, extended period of time improved the preventive efficacy of SAP (P_11-4) compared to the other regimens.

Evaluation of Remineralization Potential of Natural Substances on Artificially Induced Carious Lesions in Primary Teeth: An In Vitro Study

Aim

To evaluate the remineralizing potential of natural substances on artificially induced caries lesions in primary teeth.

Materials and methods

A total of 50 primary molar teeth were selected and subjected to a demineralization process. Then samples were randomly divided into five groups for the remineralization process. Group I-colophony, group II-5% sodium fluoride (NaF) + colophony, group III-grape seed extract (GSE) + colophony, group IV-5% NaF + colophony + 10% peptide, and group V- GSE + colophony + 10% peptide. All the groups were subjected to remineralization using a brushing stimulator for 3,000 cycles. Assessment was done using Vickers hardness testing machine for evaluating the enamel surface microhardness (SMH) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) for evaluating the surface morphology and mineral content, before and after demineralization and after remineralization, the obtained data was analyzed statistically using IBM Statistical Package for the Social Sciences (SPSS) software version 25.

Results

The enamel microhardness results of this study revealed that remineralization of enamel was highest in group V (212.83 ± 64.416) and least in group II (137.83 ± 26.324) p-value of 0.038. SEM-EDX analysis revealed high calcium (Ca) and fluoride (F) content in groups II and IV, which was significant (p-value of 0.001) from other groups. Surface morphology evaluated with SEM revealed spherical globular agglomerates and scaffolding deposits on the enamel surface in groups III and V resembling the remineralization process.

Conclusion

Grape seed extract (GSE) with colophony and peptide is a superior natural alternative to NaF. Colophony also exhibited remineralizing potential in primary enamel.

Clinical significance

Natural remineralizing agents like GSE, colophony, and its combination serves as a potential alternative to overcome the toxic effect on long-term usage of F. These natural substances can be applicable in clinical conditions by incorporating toothpaste and varnish, which can be used as an alternative or adjuvant to the topical application of F.

How to cite this article

Pooja V Ravi, Rajakumar S, Kavitha Ramar. Evaluation of Remineralization Potential of Natural Substances on Artificially Induced Carious Lesions in Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(2):244-250.

The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion

This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

Evaluation of the changes in physical properties and mineral content of enamel exposed to radiation after treating with remineralization agent

OBJECTIVE

The aim of this study was to investigate the effect of different remineralization agents on the physical properties and elemental content of enamel exposed to radiation.

MATERIAL AND METHOD

The enamel surfaces of impacted third molar teeth were prepared, and six study groups were created (n = 6). Next, 60 Gy radiation was applied to each group. Between applications, each group except for the control group was treated with a different remineralization agent (sodium fluoride, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), casein phosphopeptide amorphous calcium phosphate with fluorite (CPP-ACFP), bioactive glass, or chitosan). The results were evaluated in terms of pre- and post-radiation values and the difference between the two. The paired-samples t test and analysis of variance test were used in the analysis of normally distributed hardness and roughness values, while Wilcoxon's signed ranks test, and the Kruskal Wallis and Mann-Whitney U tests were used in the analysis of elemental content without normal distribution.

RESULTS

A statistically significant decrease was observed in microhardness measurements in all groups. Intragroup evaluation revealed a statistically significant difference between the NaF and bioactive glass groups (p < 0.05). No significant difference was observed between the groups' roughness measurements (p < 0.05). Intergroup evaluation of surface roughness revealed a significant difference in the CPP-ACFP and chitosan groups (p < 0.05). Pre- and post-radiation oxygen, magnesium, and potassium levels and Ca/P ratios also differed significantly (p < 0.05).

CONCLUSION

Radiation caused a statistically significant difference in the microhardness and elemental content of enamel. However, no significant difference was observed in enamel roughness. The applied remineralizing agents have a partial ameliorating effect on the adverse impacts of radiation.

CLINICAL RELEVANCE

Radiation causes changes in the mechanical properties and elemental content of tooth enamel. Remineralizing agent application is a promising option in reducing the adverse effects of irradiation.

Enamel Remineralization Competence of a Novel Fluoride-Incorporated Bioactive Glass Toothpaste-A Surface Micro-Hardness, Profilometric, and Micro-Computed Tomographic Analysis

This study aimed to analyze the enamel remineralization efficacy of a novel fluoridated bioactive glass (F-BG) toothpaste compared to a standard fluoride toothpaste. Seventy-two enamel blocks (N = 72) were divided into groups of twenty-four blocks according to the toothpaste exposure—group 1: brushed with distilled water, group 2: brushed with fluoride toothpaste (Colgate^TM), and group 3: brushed with F-BG toothpaste (BioMinF^TM). Pre-brushing, enamel blocks were demineralized using 6 wt.% citric acid (pH = 2.4). Tooth brushing was performed using a mixture of respective toothpaste and artificial saliva (AS), and each enamel block received 5000 linear strokes. The samples were assessed for surface micro-hardness (to estimate Vickers hardness number, VHN), surface roughness (Ra), and volume loss/gain using micro-computed tomography (micro-CT). The highest increase in the VHN was noticed for group 3 (117.81) followed by group 2 (61.13), and all the intragroup comparisons were statistically significant (p < 0.05). Demineralization increased the Ra values, and a decrease was observed post-remineralization for all the groups. The maximum Ra decrease was observed for group 3 (−223.2 nm) followed by group 2 (−55.6 nm), and all the intragroup comparisons were again statistically significant (p < 0.05). Micro-CT investigation revealed that the enamel volume decreased after demineralization and increased after remineralization among all groups. The F-BG toothpaste showed greater enamel surface micro-hardness (increased VHN), smoother surface (low roughness), and better volume restoration (remineralization) in comparison to the fluoride toothpaste.

Effectiveness of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) Compared to Fluoride Products in an In-Vitro Demineralization Model

The goal of this study was to evaluate the effectiveness of the toothpaste Tooth Mousse compared to conventional fluoride-based versions in the prevention of enamel and dentin demineralization. Human enamel and dentin samples (n = 120 each) were exposed to artificial demineralization at pH 4.92. During the demineralization process, the samples in the test groups were periodically treated with Tooth Mousse (TM) containing casein-phosphopeptide -amorphous-calcium-phosphate (CPP-ACP) and Tooth Mousse Plus (TMP) containing amorphous-calcium-fluoride-phosphate (CPP-ACPF) to evaluate their protective properties. Fluoride toothpastes containing 1400 ppm amine fluoride (AmF) and 1450 ppm sodium fluoride (NaF) were applied in the positive control groups. Treatment with distilled water (group C-W) or demineralization without treatment (group C-D) served as negative controls. After the demineralization and treatment process, all samples were cut longitudinally and lesion depths were determined at six locations using polarized light microscopy. In TM/TMP groups (enamel: 80/86 µm, dentin: 153/156 µm) lesion depths were significantly smaller compared to the negative control groups C-W/C-D (enamel: 99/111 µm, dentin: 163/166 µm). However, TM and TMP compared to the positive controls AmF/NaF (enamel: 58/63 µm, dentin: 87/109 µm) showed higher lesion depths. The application of TM/TMP (89%/78%) during demineralization led to a reduced number of severe lesions compared to the negative controls C-W/C-D (100%/95%). In this study we demonstrate that Tooth Mousse is less effective regarding prevention of enamel and dentin demineralization compared to fluoride containing toothpastes.

Evaluation of the Efficacy of Different Remineralizing Agents on Artificial Early Enamel Lesions of Primary Teeth: An In Vitro Study

Aim:

To analyze the remineralization efficacy of casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) and 8% arginine on artificial early enamel lesions on primary teeth enamel samples.

Materials and Methods:

In this in vitro study, artificial enamel lesions were created in 120 primary teeth. Teeth were randomly divided into 5 groups: group C: CPP–ACP paste; group CF: CPP–ACPF paste with 900 ppm flour; group A: paste with 8% arginine; group K+: 500 ppm NaF as a positive control; and group K–: deionized water as a negative control. After 4 weeks of the remineralization process, the effect of remineralization on samples of agents used the microhardness, atomic force microscope, and scanning electron microscope analyses. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS version 20.0, SPSS Inc., Chicago, IL, USA). ANOVA and Tukey Post-Hoc multiple comparison test were applied ( p < .05).

Results:

Increasing percentage values of the microhardness at groups C, CF, and A were significantly better than group K– ( p < .05), whereas there is no statistically significant difference with group K+ ( p > .05). The average surface roughness values of groups C and CF were similar with group K+ in AFM analysis, whereas average surface roughness values of group A were significantly higher than K+ group.

Conclusion:

The CPP–ACP, CPP–ACPF, and arginine are effective agents for remineralization of early childhood caries lesions.

Complementary remineralizing effect of self-assembling peptide (P11-4) with CPP-ACPF or fluoride: An in vitro study

Background

Self-assembling peptide has been recently introduced to promote hard tissue regeneration for treating early non-cavitated carious lesions. This study investigates the efficacy of biomimetic self-assembling peptide (P11-4) on enamel remineralization combined with CPP-ACPF or fluoride.

Material and Methods

Artificial enamel lesions were created on buccal surface of 60 specimens and were randomly assigned to six groups according to the remineralizing agent: G1-(Control, artificial saliva), G2-(Fluoride varnish), G3-(CPP-ACPF varnish), G4-(Self-assembling peptide), G5-(Self-assembling peptide+fluoride varnish), G6-(Self-assembling peptide+CPP-ACPF varnish). All products were applied according to manufacturer’s instructions and specimens were stored in a daily renewed artificial saliva. Surface microhardness (SMH) and scanning electron microscope (SEM) were assessed at baseline, after demineralization, 1 week and 4 weeks storage. SMH values were analyzed using ANOVA and Tukey’s post-hoc test.

Results

The highest statistically significant SMH values were found in G6 followed by G5, G4, G2 and G3 while the lowest values were found in G1. No statistically significant difference was found between G5 and G6. Also, no statistically significant difference was found between G2 and G3. SEM showed that G4, G5, G6 resulted in more pronounced remineralization, reversing the demineralized enamel fish scale pattern compared to G2 and G3 after 1 week and 4 week remineralization.

Conclusions

Complementary effect was obtained after combining self-assembling peptide with CPP-ACPF or fluoride showing the highest remineralizing potential early after 1 week and even after 4 weeks compared to when each agent used alone. Added benefits can be obtained through combining self-assembling peptide with other remineralzing agents allowing faster and enhanced regeneration of non-cavitated caries lesions.

Key words:Enamel regeneration, biomimetic remineralization, self-assembling peptide, CPP-ACPF, fluoride.

Enhancing the detection of proximal cavities on near infrared transillumination images with Indocyanine Green (ICG) as a contrast medium: In vitro proof of concept studies

OBJECTIVES

The use of near infrared transillumination for caries detection is gaining recognition in daily practice. Differentiation between cavitated and non cavitated proximal lesions is recognized as a threshold for restorative treatment. This investigation focused on the use of a near infrared absorbent dye which may enhance the detection of cavitation on near infrared transillumination images.

MATERIALS AND METHODS

1: Natural teeth with artificial proximal cavitation were images with 3 different dyes to establish that near infrared absorbent dye can act like a contrast medium. 2: Natural teeth with natural cavitated lesions were used to investigate the contrast enhancing effect of indocyanine green (ICG) on near infrared transillumination images. 3: Artificial teeth with artificial cavitations were used to determine the best consistency of ICG as a contrast medium. 4: natural teeth with proximal lesions were used to confirm that ICG can differentiate between cavitated and non cavitated proximal lesions.

RESULTS

1: ICG enhanced the contrast of cavitations compared to other dyes (ANOVA; p < 0.05). 2: ICG enhanced the contrast of the cavitated area on natural lesions but not significantly (t-test; p > 0.05). 3: ICG in a gel form enhanced the detection of cavitated lesions when compared to liquid ICG (t-test; p < 0.05). 4: ICG gel was able to differentiate between cavitated and non cavitated proximal lesions (ANOVA; p < 0.05).

CONCLUSION

ICG can potentially be used as a contrast medium to enhance the detection of cavitated proximal lesions in vitro on near infrared transillumination images. A clinical study is required to validate these results in vivo.

Effects of treatment with three types of varnish remineralizing agents on the microhardness of demineralized enamel surface

Background

Remineralization of incipient caries is one of the goals in dental health care ,especially in pediatric dentistry. The present study aimed at comparing the effects of MI varnish (3M (United states)) , Nano paste( FGM(Brezil) ), 5% sodium fluoride varnish) DuraphatColgate (united states) ) on remineralization of enamel lesions.

Material and Methods

In this in-vitrostudy, 60 intact human pre-molars, were randomly allocated to four groups of 15. Baseline surface microhardness in three points in the center of the polished area was measured. After two days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went treatment with MI varnish, nano paste, 5% sodium fluoride varnish and then again microhardness was measured. The results were analyzed by one-way analysis of variance (ANOVA), repeated measures ANOVA, and Bonfreni table was used.

Results

Duraphat varnish in comparison with control group, significantly increased surface microhardness and in comparison with Nano and MI paste varnish groups significant differences was shown between groups. (P< 0.05). MI paste varnish and Nano paste similary showed more increases in surface microhardness in comparison with Duraphat varnish and control groups (P≈1).

Conclusions

According to the results of this study, all three varnishes, Duraphat , MI paste and Nano paste increase the enamel surface microhardness and remineralization of incipient caries. MI paste and Nano paste compared to Duraphat Varnish, significantly showed more increases in enamel surface microhardness but Nano paste and MI paste were almost the same. Key words:CPP-ACP, Nano varnish, fluoride varnish, microhardness, demineralization, remineralization.

Effect of addition of bioactive glass to resin modified glass ionomer cement on enamel demineralization under orthodontic brackets

Background

Enamel demineralization and white spot lesions around orthodontic brackets is a common problem associated with fixed orthodontic treatment. Glass ionomer cements (GICs) are commonly used for bracket bonding and recently, bioactive glass (BAG) was added to GICs to enhance deposition of calcium phosphate in adjacent dental structure. This study sought to assess the effect of addition of BAG particles to resin modified GIC (RMGIC) on enamel demineralization under orthodontic brackets.

Material and Methods

In this in vitro, experimental study, 60 sound human premolars were immersed in distilled water at 6°C. The teeth were randomly divided into three groups. Using a sticker, a window measuring 7x7 mm was created on the buccal surface. The remaining surfaces were coated with nail varnish twice with a 3-hour interval. After 24 hours, the stickers were removed. Brackets were bonded to tooth surfaces using Transbond XT (control), Fuji II LC RMGIC and Fuji II LC containing 30% BAG particles. To induce acid attacks, the teeth were immersed in demineralizing solution for 6 hours. For pH cycling, the teeth were then immersed in remineralizing solution for 18 hours. This process was repeated for 21 days. Next, the teeth were longitudinally sectioned into two halves and the depth of demineralization was measured from the deepest point to the surface under a polarized light microscope. Data were analyzed using one-way ANOVA, and pairwise comparisons were carried out using Tukey’s test.

Results

The mean depth of demineralization was 73.8±22.29, 118.08±29.42 and 182.98±20.69 µm in the BAG, RMGIC and Transbond XT groups, respectively. One-way ANOVA showed significant differences in terms of depth of demineralization among the three groups (P=0.0001). Tukey’s test revealed significant differences in depth of demineralization.

Conclusions

Addition of BAG to RMGIC can significantly decrease the depth of enamel demineralization under orthodontic brackets in vitro.

Key words:Remineralization, demineralization, orthodontic brackets, bioactive glass, resin modified glass ionomer cement.

Influence of Er, Cr: YSGG (2780 nm) and Nanosecond Nd: YAG Laser (1064 nm) Irradiation on Enamel Acid Resistance: Morphological and Elemental Analysis

BACKGROUND

Enamel demineralisation is an initial step of the serious dental problem including dental caries, white spot lesions and dental erosion.

AIM

Compare the effect of Er, Cr: YSGG (λ = 2780 nm) and nanosecond Nd: YAG (λ = 1064 nm) laser on enamel acid resistance.

MATERIAL AND METHODS

Thirty non-carious human premolars, extracted for orthodontic reasons, were used. The experimental groups (n = 10 each group) were: Group I, untreated (control); Group II, Er, Cr: YSGG laser irradiation (0.75 W, 20 Hz, 140 μs, 10 s); Group III, nanosecond pulsed Nd: YAG laser irradiation (0.8 W, 10 Hz, 7 ns, 10 s). Scanning electron microscope and Energy Dispersive X-ray Spectroscopy (EDX) were used to assess acquired enamel resistance to PH cycling.

RESULTS

After subjecting the three experimental groups to PH cycling, scanning electron microscopic examination revealed irregular porous dissoluted enamel surface in group I. However, groups II and III demonstrated partially dissoluted enamel surface. EDX analysis demonstrated the lowest mean percentage decrease in calcium and phosphorus content in group II followed by group III, then the highest mean percentage decrease was observed in untreated group I. One-way ANOVA revealed significant differences (p < 0.0001) between the tested groups.

CONCLUSIONS

Both Er, Cr: YSSG and nanosecond Nd: YAG laser irradiation were able to improve the acid resistance of enamel. However, enamel surface treated with Er, Cr: YSSG laser showed the lowest mean percentage decrease of calcium and phosphorus (highest acid resistance).

Efficacy of different remineralization agents on treating incipient enamel lesions of primary and permanent teeth

Aims and Objectives:

The aim of this study was to compare the in vitro efficacy of different remineralization (RM) agents on RM of artificial caries by evaluating the density, light reflection, and the crystal size of the newly formed mineral in primary and permanent teeth.

Materials and Methods:

Caries-free primary and permanent molars were divided into seven groups (n = 20) and treated with: G1 – Deionized water, G2 – Colgate Cavity Protection, G3 – Sensodyne Rapid Relief, G4 – GC MI Paste Plus, G5 – Clinpro Tooth Creme, G6 – Clinpro 5000, and G7 – Sensodyne Repair and Protect. Lesion depths were evaluated using laser fluorescence (DIAGNOdent), and polarized light microscopy (PLM), and the minerals were evaluated using X-ray diffractometry (XRD).

Results:

The highest decrease in laser fluorescence readings was observed in G6 for both primary and permanent teeth. No significant difference was observed between G2, G4, G5, and G6 in permanent teeth and G4 and G6 in primary teeth (P > 0.05). In PLM analyses, lesions depths were found to be lower in G6 compared to the other groups. No significant difference was observed between G2, G4, and G6 (P < 0.05). XRD evaluation showed that the newly formed mineral in G6 was denser and highly crystallized compared to the other groups.

Conclusion:

This in vitro study demonstrated that Clinpro 5000 is more efficient in remineralizing incipient enamel lesions compared to the other agents tested.

The Effect of MIpaste Plus and Reminpro on Incipient Caries Using DIAGNOdent and SEM: An Invitro Study

BACKGROUND

The remineralization of early caries lesion has an effective role on decreasing caries. For initial remineralization of caries lesion, using Compounds of Casein phosphopeptides (CPP) in different studies has been proposed. REMINPRO including Fluoride, Xylitol and Calcium phosphate has just been offered in the market. This study aims to investigate the efficacy of Reminpro and MI paste plus in terms of remineralization of early enamel lesions.

MATERIALS AND METHODS

In 15 samples of healthy enamels of the maxillary first premolar teeth and 15 samples of Primary Mandibular First Molar under the effect of demineralized gel, artificial caries has been created. The samples have been divided in 3 groups of 20. After performing the cycles of demineralization and remineralization during 5 weeks, the samples were investigated by DIAGNOdent and two samples from each group were compared with SEM. To investigate the remineralization of enamel, two-way ANOVA and to compare the groups in pair, the post hoc tests were used.

RESULTS

The mean of mineralization of teeth in the group using reminpro was 25.2 ± 6.16 and in the group using MI paste plus was 23 ± 5.60, which was significantly high.

CONCLUSIONS

MI paste plus in mineralization of initial enamel caries were more efficient that reminpro pate.

In Vitro Evaluation of Enamel Microhardness after Application of Two Types of Fluoride Varnish

INTRODUCTION

Use of fluoride compounds is one of the most effective ways of preventing decay and among these varnishes have high acceptance among different fluoride products.

AIM

Hence, the aim of this research was to evaluate the micro-hardness of tooth enamel after the usage of two different commercial products of fluoride varnish.

MATERIALS AND METHODS

This in vitro experimental study was performed on 51 extracted premolar teeth. The teeth were divided randomly into three 17-membered groups. The first group received Duraflor varnish, the second group received Ariadent Iranian varnish while the third group received no treatment. Micro hardness of tooth enamel was measured utilizing Vickers method before and after the use of fluoride varnish. ANOVA, Tukey, and Wilcoxon statistical tests were utilized for statistical analysis of data.

RESULTS

The comparison of mean change in micro hardness before and after the use of fluoride showed that increase in micro hardness in Duraflor varnish and Ariadent varnish group was significant when compared to control group (p<0.05) but no significant statistical difference was observed in terms of mean of micro hardness after intervention between two groups of Duraflor varnish and Ariadent varnish (p>0.05).

CONCLUSION

According to the findings, the use of fluoride significantly increased the enamel micro hardness which did not show a significant difference between two groups of Duraflor varnish and Ariadent varnish.

Randomized clinical trial of the effect of NovaMin and CPP-ACPF in combination with dental bleaching

OBJECTIVE

This randomized, controlled, double-blind clinical study evaluated the effect of calcium sodium phosphosilicate (NovaMin) and casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF) on the prevention of post-operative sensitivity and on the effects of clinical bleaching treatment.

MATERIAL AND METHODS

Sixty volunteers were selected according to inclusion and exclusion criteria and were randomly assigned into three groups (n=20): CG (control group) patients, who were treated with 35% hydrogen peroxide; NOVAG (NovaMin group) patients, who were treated with 35% hydrogen peroxide followed by the application of NovaMin; and CPPG (CPP group) patients, who were treated with 35% hydrogen peroxide followed by the application of CPP-ACPF. Both bioactive agents were applied for five minutes. An evaporative stimulus associated with a modified visual scale was used to analyze sensitivity 24 hours after each bleaching session. The color evaluation was performed on the maxillary central incisors using a spectrophotometer. Associations between the intervention group, bleaching session, and reported sensitivity were tested using Chi-square partitioning.

RESULTS

Color change values (ΔE) were analyzed using analysis of variance (ANOVA). The significance level used for both tests was 5%. In the intragroup assessment, the Friedman test showed that only the CPP-ACPF group showed no statistically significant difference (p<0.05) between baseline and first bleaching session. In the intergroup assessment, the Kruskal-Wallis test showed that the CPPG had less postoperative sensitivity after the first session, when compared to the other groups (p<0.05). Color change analysis (ΔE) showed a significant difference between the means obtained in the different bleaching sessions in all groups (p<0.05).

CONCLUSIONS

This study showed that the combination of CPP-ACPF with 35% hydrogen peroxide significantly reduced post-operative sensitivity in the first session, compared with the other evaluated treatments. The association of CPP-ACPF and NovaMin did not affect the color change induced by tooth bleaching.

Assessment of Enamel Remineralisation After Treatment with Four Different Remineralising Agents: A Scanning Electron Microscopy (SEM) Study

INTRODUCTION

Decades of research has helped to increase our knowledge of dental caries and reduce its prevalence. However, according to World Oral Health report, dental caries still remains a major dental disease. Fluoride therapy has been utilised in a big way to halt caries progression, but has been met with limitations. This has paved the way for the development of newer preventive agents that can function as an adjunct to fluoride or independent of it.

AIM

The purpose of the present study was to evaluate the ability of Casein Phosphopeptide-Amorphous Calcium Phosphate Fluoride (CPP ACPF), Bioactive Glass (BAG), fluoride enhanced Hydroxyapatite (HA) gel and self-assembling peptide P₁₁-4 to remineralise artificial carious lesions in enamel in vitro using a 30 day pH cycling model through surface microhardness analysis and SEM.

MATERIALS AND METHODS

Sixty enamel samples were divided into five groups of 12 samples each. The control Group A consisted of intact enamel samples, Group B: CPP-ACPF (Tooth Mousse Plus), Group C: BAG (SHY- NM), Group D: fluoride enhanced HA gel (ReminPro) and Group E: Self-assembling peptide P₁₁-4 (Curodont Protect). All groups excluding the control group were subjected to demineralisation following which four of these groups were remineralised using the four remineralising agents. The treated groups were subjected to pH cycling over a period of 30 days. This was followed by assessment of surface microhardness and SEM for qualitative evaluation of surface changes. The results were analysed by One-Way Analysis Of Variance (ANOVA). Multiple comparisons between groups were performed by paired t-test and post-hoc Tukey test.

RESULTS

The results of the study revealed that remineralisation of enamel was the highest in samples of Group E (Self assembling peptide P₁₁-4) followed by Group B (CPP-ACPF), Group C (BAG) and Group D (fluoride enhanced HA gel). There was a significant difference (p<0.05) in the remineralising ability between the self assembling peptide P₁₁-4 group and BAG and fluoride enhanced HA gel group. Although no significant difference was observed between the self assembling peptide P₁₁-4 and CPP-ACPF group, the self assembling peptide P₁₁-4 remineralised the enamel lesions more effectively. SEM photomicrographs of the test groups demonstrated either amorphous crystals or particles scattered on the surface or lines of remineralisation along the prismatic borders.

CONCLUSION

Self assembling peptide P₁₁-4 demonstrated promising results by effectively and significantly remineralising the enamel lesions as compared to other test agents.

Comparison of CPP-ACP, Tri-Calcium Phosphate and Hydroxyapatite on Remineralization of Artificial Caries Like Lesions on Primary Enamel -An in vitro Study

OBJECTIVES

To compare CPP-ACP, Tri-calcium phosphate and Hydroxyapatite on remineralization of artificial caries like lesions on primary enamel.

STUDY DESIGN

Ten extracted Primary molars coated with nail varnish, leaving a window of 2×4 mm on buccal and lingual surface were immersed in demineralizing solution for 96 hours and sectioned longitudinally to obtain 40 sections (4 sections per tooth) and were randomly divided into 4 groups (A to D) n=10; Group A: negative control, Group B: CPP-ACP, Group C: Tri-calcium phosphate, Group D: Hydroxyapatite. Sections were subjected to pH cycling for 10 days and were evaluated by polarized light microscope before and after treatment.

RESULTS

Intra group comparison of demineralization and remineralization was done by paired t-test. One way ANOVA was used for multiple group comparisons followed by post HOC TUKEY'S Test for group wise comparisons. Remineralization was found more with Group D followed by Group B, C and A.

CONCLUSION

Hydroxyapatite showed better remineralization when compared to CPP-ACP and Tri-calcium phosphate.

Effect of three nanobiomaterials on microhardness of bleached enamel

OBJECTIVES

The aim of this in vitro study was to evaluate the effect of incorporating three different nanobiomaterials into bleaching material on microhardness of bleached enamel.

MATERIALS AND METHODS

The crowns of 24 extracted sound human molars were sectioned. Sixty enamel specimens (2 × 3 × 4 mm) were selected and divided into five groups (n = 12): Group 1 received no bleaching procedure (control); Group 2 underwent bleaching with a 40% hydrogen peroxide (HP) gel; Groups 3, 4, and 5 were bleached with a 40% HP gel modified by incorporation of bioactive glass (BAG), amorphous calcium phosphate (ACP) and hydroxyapatite (HA), respectively. The enamel microhardness was evaluated. The differences in Knoop microhardness data of each group were analyzed by one-way ANOVA, followed by post hoc Tukey tests.

RESULTS

Significant differences were observed between the study groups. The enamel microhardness changes in Groups 1, 3, 4, and 5 were significantly lower than that of Group 2 (p < 0.001).

CONCLUSIONS

Within the limitations of this study, it can be concluded that incorporation of each one of the three tested biomaterials as remineralizing agents might be effective in decreasing enamel microhardness changes subsequent to in-office bleaching.

Remineralizing Effect of Topical NovaMin and Nano-hydroxyapatite on caries-like Lesions in Primary teeth

INTRODUCTION

NovaMin is a synthetic mineral compound composed of calcium, sodium, phosphorus, and silica. It releases crystalline hydroxyl-carbonate apatite (HCA), which structurally resembles the minerals naturally found in the teeth. Nano-hydroxyapatite (NHA) is a biocompatible compound with high affinity for tooth enamel. NHA particles morphologically resemble dental enamel apatite crystals. Considering the efficacy of remineralizing agents and the importance of conservative preventive measures, this study aimed to compare the remin-eralizing effects of NovaMin and NHA on caries-like lesions in primary teeth.

MATERIALS AND METHODS

This in vitro experimental study was conducted on 30 sound human primary anterior teeth with no cracks or fractures. The surface microhardness (SMH) of each tooth was measured at baseline using a Vickers microhard-ness tester. The teeth were then subjected to remineralization/ demineralization cycles, and artificial caries lesions were created in them. The SMH of each tooth was measured again and the teeth were then randomly treated with toothpastes containing NovaMin or 10% NHA powder for 2 minutes daily for a period of 5 days. The SMH of each was again measured afterward. Data were statistically analyzed using independent t-tests and Mann-Whitney U tests.

RESULTS

The mean SMH was found to be higher in the teeth treated with NovaMin toothpaste (422.67 kgf/mm(2)) than in the teeth treated with NHA (384.2 kgf/mm(2)); However, this difference was not statistically significant.

CONCLUSION

Both NHA and NovaMin were effective for reminer-alization of caries-like lesions of primary teeth and no significant difference was detected in their efficacy.

Remineralizing potential of CPP-ACP creams with and without fluoride in artificial enamel lesions

BACKGROUND

This study evaluated the effect of pastes containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) with and without fluoride on enamel demineralization.

METHODS

Human enamel blocks were used and after incipient caries-like lesions were formed, they were assigned to four groups: G1 - saliva; G2 - MI Paste (Recaldent^TM ); G3 - MI Paste Plus (Recaldent^TM 900 ppm as NaF); and G4 - Crest^™ (1.100 ppm as NaF). The specimens were soaked in demineralizing solution for 6 hours and remineralized in artificial saliva for 18 hours alternatively for 10 days. The dentifrice was prepared with deionized water in a 1:3 proportion (w/w) or applied undiluted in the case of the CPP-ACP formula. Demineralized enamel changes were analysed by surface microhardness (SMH), 3D-profilometry and SEM. Data were analysed by non-parametric Kruskal-Wallis and Mann-Whitney test comparisons and one-way ANOVA and Tukey's HSD post hoc test (α = 0.05).

RESULTS

The SMH values observed in the G2 (47.8 ± 28.5) and G3 (53.6 ± 27.6) groups were different from that of G4 (90.2 ± 17.1), which were significantly higher than that found in G1 (39.4 ± 14.2). The %SMH was significantly lower in G4 when compared to G1 (p < 0.001) and G3 (p < 0.05).

CONCLUSIONS

MI Paste Plus demonstrated a greater protective effect against demineralization than MI Paste and showed smoother surfaces.

Influence of Pastes Containing Casein Phosphopeptide-amorphous Calcium Phosphate on Surface of Demineralized Enamel

Purpose

The purpose of the study was to evaluate the surface characteristics of demineralized enamel after treatment with pastes containing casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) or casein phosphopeptide–amorphous calcium fluoride phosphate (CPP-ACFP) and to compare their efficacy with that of 0.05% NaF.

Methods

Following formation of the artificial carious lesion, enamel slabs were divided into 4 groups (CPP-ACP, CPP-ACFP, 0.05% NaF and control) and submitted to a chemical caries model. Remineralization potential was examined using scanning electron microscope, energy-dispersive spectroscopy (EDS) and microhardness test. Scanning electron microphotographs were analyzed for area, minimal, maximal and mean diameter, perimeter, roundness and number of enamel defects and percentage of tooth surface affected by defects.

Results

Treatment with 0.05% NaF partly reduced the appearance of enamel defects when compared with irregular demineralized enamel. Treatment with CPP-ACP or CPP-ACFP resulted in occlusion of defects which produced more flattened enamel surface. Image analysis revealed reduction of the dimensions of the defects in the 3 experimental groups. Treatment with CPP-ACFP decreased the number of enamel defects when compared with demineralized enamel. The EDS analysis did not show differences in Ca/O, P/O and Ca/P ratios between the groups (P>0.05). Microhardness test revealed significant effects of CPP-ACP and CPP-ACFP (P<0.05).

Conclusions

Pastes containing CPP-ACP or CPP-ACFP showed potential to remineralize enamel surface lesions.

Remineralizing potential of various agents on dental erosion

AIM

The purpose of this study is to compare the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, Tooth Mousse) containing and casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF, Tooth Mousse Plus) containing pastes on dental erosion.

MATERIALS AND METHODS

Thirty permanent non-carious premolars indicated for orthodontic extraction were included in this study and were sectioned in mesiodistal direction vertically. After immersion in the carbonated drink for 14 min, samples were treated with various remineralizing pastes which were CPP-ACP containing paste (Tooth Mousse) and CPP-ACPF containing paste (Tooth Mousse Plus) according to the manufacturer's instructions. Vickers Microhardness was recorded at baseline, after exposure to erosive drink and after treatment with remineralizing pastes. Data obtained was statistically analysed using Student t-test with a level of significance set at p < 0.05.

RESULTS

CPP-ACP (Tooth Mousse) and CPP-ACP with fluoride (Tooth Mousse Plus) resulted in 30.52% and 38.98% increase in post-erosion microhardness values respectively. The remineralizing potential of CPP-ACP with fluoride containing paste (Tooth Mousse Plus) was significantly better than that of CPP-ACP containing paste (Tooth Mousse) (p < 0.05).

CONCLUSION

Casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF, Tooth Mousse Plus) can be recommended to be used in preventing erosive tooth wear from acidic beverages.

Effect of incorporation of remineralizing agents into bleaching gels on the microhardness of bovine enamel in situ

AIM

This study evaluated the effect of adding calcium or fluoride to 35% hydrogen peroxide (HP) bleaching gel and the effect of human saliva on the microhardness of sound and demineralized enamel, using an in situ model.

MATERIALS AND METHODS

Cylindrical bovine enamel specimens (3 × 2 mm) were divided into two groups (n = 30): sound enamel (SE) and demineralized enamel (DE). Each group was divided into three subgroups, according to the bleaching gel: 35% HP; 35% HP + calcium; 35% HP + fluoride. After bleaching therapy, the specimens were fixed to intraoral devices worn by 10 volunteers for 7 days. Surface enamel microhardness (SMH) was measured before and after bleaching procedures, and after 1 and 7 days of saliva exposure. Data were analyzed by Repeated Measures ANOVA (5%).

RESULTS

The variable time resulted in significant differences for SE and DE groups (p = 0.001). For SE, significantly lower SMH was detected for control at post-bleaching period in comparison to the baseline and after 7 days. For DE, the lowest mean values were obtained before bleaching, and the addition of calcium to the peroxide significantly increased enamel SMH. The exposure to human saliva resulted in increased SMH.

CONCLUSION

The addition of potential remineralizing agents into bleaching gels might play an important role in maintaining the microhardness of sound enamel and in inducing remineralization of artificially demineralized enamel right after bleaching, and the remineralizing action of human saliva might minimize the deleterious effects of bleaching gels on enamel. Clinical significance: The incorporation of calcium into HP bleaching gel might be beneficial for the initial phases of the bleaching procedure.

A pilot study of a modified radiographic technique for detecting early proximal cavities

Diagnosing the necessity of cavity preparation in demineralized proximal areas has been considered as a challenge in restorative treatment planning. The purpose of this study was to investigate the clinical performance of a modified radiographic technique for the detection of proximal cavities. The sample consisted of 44 proximal surfaces in 38 dental students. The patients had radiolucent proximal lesions restricted to the inner half of enamel or the outer third of dentine in bitewing radiographs, and there was doubt regarding the presence or absence of cavities in the approximal areas. The suspected surfaces were then examined by secondary bitewing radiographs which were taken after pressing radiopaque material into the proximal areas. Finally, orthodontic elastic separators were placed in the contact areas to provide enough space for direct visual and tactile examination, thus detecting any proximal cavity (reference standard). The sensitivity, specificity and accuracy of the modified bitewing radiography were calculated against the reference standard. Overall, 7 surfaces presented caries cavities according to the reference standard. All proximal radiolucencies observed in the inner half of enamel and 46% of those extended to the outer third of dentine were not cavitated when evaluated by direct visual and tactile examination. The sensitivity, specificity and accuracy of bitewing radiography with opaque material for detecting proximal cavities (n = 7) were 86, 100 and 98%, respectively. The tested radiographic technique displayed good validity in this pilot study for detecting proximal cavities in posterior teeth and should be further investigated.

Evaluation to determine the caries remineralization potential of three dentifrices: An in vitro study

Aim:

The aim of this study was to evaluate the remineralizing potential of three different remineralizing agents (GC tooth Mousse, Clinpro tooth crθme and SHY-NM) on demineralized tooth surfaces using micro CT and microhardness.

Materials and Methods:

Forty five freshly extracted mandibular premolars were collected and enamel specimens were prepared. The samples were assigned to three groups with fifteen specimens in each group. The specimens were then demineralized using McInne's demineralizing solution in two cycles. After that, remineralization was carried out in two cycles for 30 days using Casein phosphopeptide - Amorphous calcium phosphate (CPP - ACP), 0.21% sodium fluoride - Tricalcium phosphate (f-TCP) and Calcium Sodium Phosphosilicate (CSP) containing tooth pastes for groups I, II, III respectively. The specimens were evaluated for Linear attenuation co-efficient using micro CT (Scanco™) and Vicker's Micro Hardness (Schimadzu™) testing at different time periods. The results were tabulated and statistically analysed.

Results:

It was observed that all the three remineralizing agents used in the study significantly increased the Linear Attenuation Co-efficient and Vicker's hardness number values of the enamel specimens following 15 days and 30 days application.

Conclusion:

CPP – ACP showed the better remineralizing potential than the other two agents and there was no statistical significant difference between f-TCP and CSP groups.

In vitro evaluation of the efficacy of laser fluorescence (DIAGNOdent) to detect demineralization and remineralization of smooth enamel lesions

Objective:

Early detection of smooth surface lesions is important for appropriate management and monitoring of dental caries. The purpose of this in vitro study was to evaluate the efficacy of laser fluorescence to detect demineralization and remineralization of smooth enamel surfaces.

Materials and Methods:

In this in vitro study, 132 enamel blocks of semi-impacted human third molars were obtained; artificial caries lesions were induced and they were submitted to the pH-cycling process to create remineralization. Superficial microhardness (SMH) and laser fluorescence (LF) analysis were performed at baseline, after demineralization, and remineralization processes. The data were analyzed by Statistical Package for Social Sciences (SPSS)-16 using analysis of variance (ANOVA), Paired samples t-test, and Pearson's correlation test.

Results:

There was a significant difference between SMH values at baseline, after demineralization and after remineralization. Also, a statistically significant difference was observed between LF values in these three stages. The LF values increased after demineralization and then decreased after remineralization, and the SMH values decreased after demineralization and increased after remineralization. There was an inverse relationship between SMH and LF only at baseline and after demineralization, but not after remineralization.

Conclusion:

The results showed that LF is an appropriate method for detection of demineralization in an in vitro condition in smooth enamel lesions, but it was not so efficient in the detection of remineralization.

Effects of 45S5 bioglass on surface properties of dental enamel subjected to 35% hydrogen peroxide

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.

Comparative evaluation of remineralizing potential of three agents on artificially demineralized human enamel: An in vitro study

INTRODUCTION

Remineralization as a treatment procedure has received much attention from clinicians. The objective of this in vitro study was to find out the efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF), and tricalcium phosphate fluoride (TCP-F) in remineralizing enamel surface on which artificial caries lesion had been created. The changes were analyzed using DIAGNOdent(®) (KaVo) and scanning electron microscope (SEM).

MATERIALS AND METHODS

A total of 52 premolars and 24 molars were selected and classified into four groups of 13 premolars and 6 molars in each: I (CPP-ACP), II (CPP-ACPF), III (TCP-F), and IV (artificial saliva). All the samples were assessed using DIAGNOdent at the baseline and after demineralization and remineralization. Ten samples were randomly selected from each group baseline after demineralization and after remineralization for surface evaluation using SEM.

RESULTS

Statistical analysis showed that all the experimental groups had a significantly higher amount of remineralization except for group IV.

CONCLUSION

All the three experimental groups showed a statistically significant amount of remineralization. However, because of the added benefit of fluoride (NaF 0.2%), CPP-ACPF (Tooth Mousse-Plus(®)) and TCP-F showed marginally more amount of remineralization than did CPP-ACP (Tooth Mousse(®)). Remineralization efficacy was TCP-F > CPP-ACPF > CPP-ACP.

Biofunctional properties of caseinophosphopeptides in the oral cavity

Caseinophosphopeptides (CPPs), bioactive peptides released from caseins, have the ability to enhance bivalent mineral solubility. This is relevant to numerous biological functions in the oral cavity (promotion of tooth enamel remineralisation, prevention of demineralisation and buffering of plaque pH). Therefore, CPPs may play a positive role as prophylactic agents for caries, enamel erosion and regression of white spot lesions. Most in vitro and in situ studies demonstrate strong evidence for the bioactivity of CPPs in the oral cavity. Nevertheless, relatively little is known concerning their use as adjuvants for oral health and more particularly regarding their long-term effects on oral health.

Effects of a fluoride-containing casein phosphopeptide-amorphous calcium phosphate complex on the shear bond strength of orthodontic brackets

The purpose of this study was to investigate the effects of enamel pre-treatment with a new fluoride-containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) complex on the shear bond strength (SBS) of brackets bonded with etch-and-rinse or self-etching adhesive systems. The material comprised 66 extracted human premolars randomly divided into six equal groups with respect to the enamel pre-treatment and adhesive system employed: 1. No pre-treatment and brackets bonded with the etch-and-rinse adhesive system (Transbond XT). 2. Pre-treatment with fluoride-containing CPP-ACP paste (MI Paste Plus) and Transbond XT. 3. Pre-treatment with non-fluoride CPP-ACP paste (MI Paste) and Transbond XT.4. No pre-treatment and brackets bonded with the self-etching adhesive system (Transbond Plus). 5 and 6. Enamel pre-treated as for groups 2 and 3, respectively, and the Transbond Plus. Bonded specimens were subjected to thermal cycling (×1000) before SBS testing. The residual adhesive on the enamel surface was evaluated after debonding with the adhesive remnant index (ARI). Data evaluation was made using one-way analysis of variance and Tukey test for SBS results, and Kruskal-Wallis test for ARI results. The results showed that enamel pre-treatment with either fluoride or non-fluoride CPP-ACP paste had no significant effect on the SBS of the self-etching adhesive system (P > 0.05). Enamel pre-treatment with non-fluoride CPP-ACP in group 3 significantly reduced the SBS of the etch-and-rinse adhesive (P < 0.001), while pre-treatment with fluoride-containing CPP-ACP paste (groups 2 and 5) did not affect debonding values (P > 0.05). The fluoride-containing CPP-ACP did not compromise the SBS of brackets bonded with the tested etch-and-rinse and self-etching systems, but its non-fluoride version significantly decreased the SBS of the etch-and-rinse adhesive system.