State of the Art Enamel Remineralization Systems: The Next Frontier in Caries Management

Acceleration of Enamel Subsurface Lesion Remineralisation by Intralesion pH Modulation

Remineralisation of demineralised enamel subsurface lesions can be enhanced by pretreatment of the lesions with base (NaOH). The aim of this study was to test the effect of intralesion pH modulation on remineralisation of demineralised enamel subsurface lesions by casein phosphopeptide-stabilised amorphous calcium fluoride phosphate (CPP-ACFP) in vitro. Two remineralisation models were utilised, the first involving 60-min cyclic pH modulation for 105 h and the second involved short-term cyclic pH modulation (12-min cycle, 240 min total duration) compared with the equivalent time of continuous treatment (200 min total duration). The intralesion pH modulation was achieved by cyclic exposure to a pH 12.9 NaOH solution and a CPP-ACFP remineralisation solution at pH 5.5. Percent remineralisation was assessed using transverse microradiography with data statistically analysed using a 2-sample Student t test. For the first model, the intralesion pH modulation group had significantly (p < 0.001) higher remineralisation (43.8 ± 6.9%) than the control group (28.2 ± 5.8%) cycled with water. For the second model, the intralesion pH modulation group had significantly (p < 0.001) higher remineralisation (23.1 ± 3.4%) than the group with continuous equivalent CPP-ACFP treatment time (1.9 ± 1.3%). In both models, intralesion pH modulation significantly accelerated remineralisation, and this was attributed to the effect pH modulation had on the diffusion gradients of ions/ion pairs and the degree of saturation with respect to apatite phases within the lesion fluid.

Bioavailable fluoride in calcium-containing dentifrices

Calcium added to dentifrices can complex with fluoride ions to reduce intra-oral bioavailability and therefore efficacy in preventing dental caries. Six commercially available dentifrices containing different types of calcium and fluoride were analyzed for total and bioavailable fluoride levels by adding 10 g of dentifrice to 30 mL of distilled deionized water and mixing vigorously for 1 min to simulate toothbrushing. One milliliter of the dentifrice/water slurry was immediately centrifuged and the supernatant removed for bioavailable fluoride analysis and the mixed slurry prior to centrifugation used for total fluoride analysis using a modified microdiffusion method. The concentration of fluoride was determined using a fluoride ion-selective electrode calibrated with internal fluoride standards. All the dentifrices had similar total fluoride concentrations to those indicated on their labels (94% to 105%). However, only one dentifrice that contained calcium in the form of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) had almost 100% (97%) of fluoride in bioavailable form. The other dentifrices contained calcium carbonate and they exhibited significantly (p < 0.001) lower bioavailable fluoride levels (27% to 61%), through the generation of poorly soluble fluoride phases. The saliva biomimetic CPP, as CPP-ACP, in a dentifrice stabilised calcium and fluoride ions to maintain fluoride's bioavailability.

A bibliometric analysis of the top 50 most cited articles published in the Journal of Conservative Dentistry

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Dentin Bond Integrity of Hydroxyapatite Containing Resin Adhesive Enhanced with Graphene Oxide Nano-Particles-An SEM, EDX, Micro-Raman, and Microtensile Bond Strength Study

The aim was to synthesize and characterize an adhesive incorporating HA and GO nanoparticles. Techniques including scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), micro-tensile bond strength (μTBS), and micro-Raman spectroscopy were employed to investigate bond durability, presence of nanoparticles inside adhesive, and dentin interaction. Control experimental adhesive (CEA) was synthesized with 5 wt% HA. GO particles were fabricated and added to CEA at 0.5 wt% (HA-GO-0.5%) and 2 wt% GO (HA-GO-2%). Teeth were prepared to produce bonded specimens using the three adhesive bonding agents for assessment of μTBS, with and without thermocycling (TC). The adhesives were applied twice on the dentin with a micro-brush followed by air thinning and photo-polymerization. The HA and GO nanoparticles demonstrated uniform dispersion inside adhesive. Resin tags with varying depths were observed on SEM micrographs. The EDX mapping revealed the presence of carbon (C), calcium (Ca), and phosphorus (P) in the two GO adhesives. For both TC and NTC samples, HA-GO-2% had higher μTBS and durability, followed by HA-GO-0.5%. The representative micro-Raman spectra demonstrated D and G bands for nano-GO particles containing adhesives. HA-GO-2% group demonstrated uniform diffusion in adhesive, higher μTBS, adequate durability, and comparable resin tag development to controls.

Development of a new approach to diagnosis of the early fluorosis forms by means of FTIR and Raman microspectroscopy

This study is aimed at investigating the features of mineralization of the enamel apatite at initial stages of fluorosis development. Samples of teeth with intact and fluorotic enamel in an early stage of the disease development (Thylstrup-Fejerskov Index = 1-3) were studied by Raman scattering and FTIR using Infrared Microspectroscopy beamline at Australian Synchrotron equipment. Based on the data obtained by optical microspectroscopy and calculation of the coefficient R [A-type/B-type], which represents the ratio of carbonation fraction of CO32-, replacing phosphate or hydroxyl radicals in the enamel apatite lattice, the features of mineralization of enamel apatite in the initial stages of development of the pathology caused by an increased content of fluorine in the oral cavity were established. Statistical analysis of the data showed significant differences in the mean values of R [A-type/B-type] ratio between the control and experimental groups for surface layers (p < 0.01). The data obtained are potentially significant as benchmarks in the development of a new approach to preventive diagnostics of the development of initial and clinically unregistered stages of human teeth fluorosis, as well as personalized control of the use of fluoride-containing caries-preventive agents.

Efficacy of P11-4 for the treatment of initial buccal caries: a randomized clinical trial

To investigate the safety and efficacy of Self-Assembling Peptide P₁₁-4 (SAP P₁₁-4) compared to placebo or fluoride varnish (FV), a randomized, controlled, blinded, split-mouth study with sequential design was conducted. Subjects presenting two teeth with White-Spot-Lesions (WSLs) were included and teeth were randomly assigned to test or control. Control received placebo at baseline (D0) and test SAP P₁₁-4, all received FV at Day 90 (D90). Standardized photographs were taken at each visit, and WSL size changes were morphometrically assessed. Hierarchical Linear Modelling, considering paired and sequential design, was used to test four hypotheses. SAP P₁₁-4 lesions (test, D90–D0) showed significant WSL size reduction compared to placebo (control, D90–D0; p = 0.008) or FV (control, D180–D90; p = 0.001). Combination of SAP P₁₁-4 and delayed FV after 90 days (test, D180–D0), showed a significant difference compared to FV alone (control D270–D90; p = 0.003). No significant difference on FV efficacy was found when SAP P₁₁-4 was applied 3 months before FV (test D270–D90; control D270–D90, p = 0.70). SAP P₁₁-4 treatment resulted in superior caries regression compared to either placebo or FV, and FV efficacy seems not to be affected by SAP P₁₁-4. SAP P₁₁-4 was found to be a safe and effective WSL treatment.

The solubility of calcium oxalates explains some aspects of their underrepresentation in the oral cavity

OBJECTIVE

Clarifying the discrepancy between frequently high oxalate concentrations present in saliva, but negligible amounts of calcium oxalate deposits found on oral surfaces.

METHODS

Studying the calcium oxalate concentration range that can lead to heterogeneous crystallization in the oral cavity. a) Minimum: calcium oxalate monohydrate (COM) seed crystals were pre-grown ([Ca²⁺] = [C₂O₄^2-] = 1 mM, 30 min, 37 °C), and then re-immersed for ≥6 h to find the solubility equilibrium concentration (no growth, no dissolution). The concentrations tested were [Ca²⁺]/[C₂O₄^2-] : 0.055/0.050, 0.060/0.055, 0.070/0.065 and 0.080/0.075 mM. Supersaturations were calculated via the Debye-Hückel-theory and COM morphologies examined by scanning electron microscopy (SEM). b) Maximum (at the heterogeneous/homogeneous crystallization equilibrium): hydroxyapatite (HA) seed crystals were used to heterogeneously crystallize COM (37 °C, 24 h), using oxalate concentrations between 0.2 and 0.5 mM and calcium concentrations of 0.5 mM. COM-forming oxalate consumption was spectroscopically examined; COM precipitates were investigated by SEM; and HA identity was confirmed by X-ray analysis.

RESULTS

Within the concentration range of [Ca²⁺]/[C₂O₄^2-]:0.060/0.055 mM (minimum) and [Ca²⁺]/[C₂O₄^2-]:0.50/0.25 mM (maximum) COM precipitates heterogeneously. In terms of mass, this corresponds to a range of 8.04-36.53 mg/l (daily) or an average of 14.32 mg COM (mimicking e.g. plaque mineralization). Higher concentrations react homogeneously (mimicking precipitation within saliva).

CONCLUSION

In vivo, only ∼0.05 % oxalate present in saliva reacts with oral surfaces daily, corresponding to ∼0.0665 μmol/l or ∼9.72 μg COM per day. Calcium-consuming calcium phosphate formation and phosphoproteins such as statherin obviously hinder intraoral COM formation.

Advances of Anti-Caries Nanomaterials

Caries is the most common and extensive oral chronic disease. Due to the lack of anti-caries properties, traditional caries filling materials can easily cause secondary caries and lead to treatment failure. Nanomaterials can interfere with the bacteria metabolism, inhibit the formation of biofilm, reduce demineralization, and promote remineralization, which is expected to be an effective strategy for caries management. The nanotechnology in anti-caries materials, especially nano-adhesive and nano-composite resin, has developed fast in recent years. In this review, the antibacterial nanomaterials, remineralization nanomaterials, and nano-drug delivery systems are reviewed. We are aimed to provide a theoretical basis for the future development of anti-caries nanomaterials.

Does delayed toothbrushing after the consumption of erosive foodstuffs or beverages decrease erosive tooth wear? A systematic review and meta-analysis

OBJECTIVE

Controversy exists regarding the effectiveness of delayed toothbrushing in decreasing erosive tooth wear (ETW). The purpose of this systematic review and meta-analysis was to assess the effects of delayed toothbrushing on ETW.

MATERIALS AND METHODS

This systematic review and meta-analysis was conducted according to the PRISMA statement and registered in PROSPERO (CRD42020200463). PubMed, Embase, and Web of Science databases were systematically searched with no publication year limits. Screening and data extraction were performed independently by two reviewers. In situ and in vitro studies comparing ETW after delayed and immediate toothbrushing following an erosive attack were included. Review Manager software 5.3 (The Cochrane Collaboration, Oxford, UK) was used for statistical analyses. Heterogeneity was assessed with the Cochran Q test and I² statistics.

RESULTS

Of the 565 potentially relevant studies, 26 full-text articles were assessed for eligibility. Twelve articles were included in the systematic review, and 11 were included in the qualitative analyses. No significant difference in the ETW of human enamel was observed between delayed and immediate toothbrushing (P = 0.13), whereas significantly less ETW of bovine enamel was observed after delayed toothbrushing (P < 0.001). No significant difference in the ETW of bovine dentin was observed between delayed and immediate toothbrushing (P = 0.34). Studies on human dentin were not available. Subgroup analyses revealed a significant contribution of the use of fluoridated toothpaste to decreasing the ETW of human enamel after erosion and toothbrush abrasion (P = 0.02).

CONCLUSIONS

Bovine and human teeth behaved differently in response to erosion and toothbrush abrasion. Delayed toothbrushing after an erosive attack was not effective at decreasing the ETW of human enamel compared to immediate toothbrushing, whereas it was effective at decreasing the ETW of bovine enamel.

CLINICAL RELEVANCE

Delayed toothbrushing alone after the consumption of erosive foodstuffs or beverages is not capable of preventing erosive enamel wear.

Comparison of the Remineralizing Effect of Brushing with Aloe vera versus Fluoride Toothpaste

Objectives  The aim of the present in vitro study is to compare the remineralization brushing effect of three toothpastes and Aloe vera (AV) gel.

Materials and Methods  Forty sound extracted teeth were placed in a demineralizing solution for 4 days and randomly assigned to four groups: group A: 1,450-ppm fluoride toothpaste; group B: AV nonfluoridated toothpaste; group C: AV 1,000-ppm fluoridated toothpaste; and group D: AV gel. A 3-minute pH cycling was performed twice a day for each group for 12 days. Specimens were analyzed before and after by scanning electron microscope—energy dispersive X-ray.

Statistical Analysis  The outcomes were analyzed by Kolmogorov–Smirnov’s tests, repeated-measures analyses of variance followed by univariate analyses, and Bonferroni’s multiple comparisons tests to compare the calcium-to-phosphorus (Ca:P) ratio within time among toothpaste groups.

Results  Following remineralization, the Ca:P ratio increased in all groups. The difference of the Ca:P ratio was not significant between groups C, D, and A. The mean ratio was significantly lower in group B ( p -value = 0.026).

Conclusions  The AV gel demonstrated a remineralization capacity equal to that of the 1,450-ppm fluoride toothpaste. In contrast, fluoride-free AV toothpaste showed a lower remineralization efficiency. Further studies are required to understand its mechanism.

Effect of Galla Chinensis on Remineralization of Early Dentin Lesion

Objective  This study aimed to investigate the efficacy of the Galla chinensis extract (GCE) on early dentin lesion remineralization.

Materials and Methods  Seventy-two dentin specimens were divided into three groups according to the treatment solution. In group S1, specimens were treated with GCE; in group S2, the specimens were treated with sodium fluoride (NaF); meanwhile, specimens of group S3 were treated with distilled water (DW). Each group was further subdivided into two subgroups according to the treatment time (1 minute and 5 minutes). An in vitro pH-cycling model for 12 days was done. Subsequently, surface microhardness (SMH) of the specimens, elemental analysis, and their micromorphological appearance were evaluated.

Statistical Analysis  Data were statistically analyzed. One-way analysis of variance was used to compare numerical (parametric) data between more than two separate groups followed by post hoc Tukey.

Results  There was no significant difference between the mean SMH of dentin between NaF and GCE groups. Regarding the time, the 5-minute treatment with NaF and DW groups recorded higher mean SMH value of dentin than the 1-minute treatment group. Meanwhile, for GCE groups, the 1-minute immersion recorded higher mean SMH value than the 5-minute immersion without any significant difference between them. The microhardness results were confirmed by environmental scanning electron microscope and energy dispersive X-ray analysis results.

Conclusion  GCE could be used as an effective alternative for dentin remineralization.

Impact of self-assembling peptides in remineralisation of artificial early enamel lesions adjacent to orthodontic brackets

Enamel demineralisation can occur as a side effect during orthodontic treatment with fixed appliances. This study aimed to evaluate the efficacy of the self-assembling peptide P11-4 for remineralisation combined with fluorides, compared to application of fluoride varnish alone. De- and remineralisation was assessed by Quantitative light-induced fluorescence (QLF). Orthodontic brackets were bonded on 108 human enamel samples and white spot lesions were created. The samples were allocated randomly into three groups: Group I received no treatment, group II had a single application of fluoride varnish (22,600 ppm), and group III was treated with P11-4 following a single application of fluoride varnish. Quantitative light-induced fluorescence (QLF) measurements were performed at baseline, after demineralisation and after storage in remineralisation solution for 7 and 30 days. Non-parametric tests (Kruskal-Wallis test and Friedman test) were used for further analysis. After demineralisation, all samples showed a median ΔF -9.38% ± 2.79. After 30 days median ΔF values were as followed: group I = -9.04% ± 2.51, group II = -7.89 ± 2.07, group III = -6.08% ± 2.79). The median ΔF values differed significantly between all groups at all investigation times (p < 0.00001). Application of P11-4 with fluoride varnish was superior to the use of fluorides alone for remineralisation of enamel adjacent to brackets.

Subsurface enamel remineralization by Lyophilized Moringa leaf extract loaded varnish

OBJECTIVE

The objective of this study was to investigate enamel remineralization using lyophilized extract from Moringa Oleifera Leaves (MOL).

MATERIALS AND METHODS

A total of seventy-five teeth were selected and randomly divided into 5 equal groups (n = 15). All teeth were air dried for 30 s, two windows (right and left) were drawn on the labial surface of each tooth. The right window was set as the control and no etching or treatment was performed. The left window was etched for 30 s for all five groups. After etching, group I received no treatment, group II received plain varnish, group III received fluoride varnish, and finally groups IV and V received plain varnish loaded with 50 mg/ml and 200 mg/ml of lyophilized MOL extract respectively. All samples were then immersed in artificial saliva for 14 days. The specimens were examined under scanning electron microscope (SEM) and energy dispersive x-ray (EDX).

RESULTS

SEM micrographs revealed that MOL extract loaded-varnish groups IV & V showed the most re-establishment of normal enamel architecture. Elemental analysis of the treated surfaces of Groups IV and V showed the surfaces treated by MOL loaded-varnish groups had significantly higher Ca, P, and O deposition than the fluoride varnish group.

CONCLUSION

MOL might be considered as a biomimetic material capable of guiding enamel tissue remineralization.

Greater caries-free survival of first permanent molars: Findings from a 7-year follow-up evaluation of a community-based oral health preventive program

BACKGROUND

The occlusal surface of the first permanent molar is the most frequently affected site by dental caries.

AIM

To assess the caries-free survival of first permanent molars in children participating in a community-based oral health preventive program.

DESIGN

This was a retrospective study conducted on 426 children under 12 years of age, beneficiaries of a preventive program from 2009 to 2015, in El Cedro, Colombia. The program offered oral health care education, supervised brushing and mouth washing, and application of topical fluoride. By using parametric survival models for interval-censored data, primary and secondary caries-free survival of any first permanent molar was estimated and analyzed.

RESULTS

Before program implementation, dental caries lesions presented at an average age, adjusted by age of eruption, of 8.3 years for primary caries lesion and 9.3 years for secondary caries lesion. After 7 years of the program, the estimated average age for presenting primary dental caries lesion was delayed by 4.6 years and by 5.3 years for secondary caries.

CONCLUSION

The implementation of the oral health program led to improved caries-free survival of first permanent molars.

Effect of CPP-ACP on remineralization of artificial caries-like lesion: an in situ study

The purpose of this double-blind, randomized, crossover in situ study is to compare remineralization of preformed enamel lesions by casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) and fluoride dentifrice products. During each of four 10-day experimental legs, 10 participants wore intraoral removable palatal acrylic appliances with four human enamel slabs with preformed lesions. A 0.03-mL treatment paste was dripped extraorally onto the enamel blocks once a day for 3 min. The four randomly allocated treatments were as follows: CO- Control: silica dentifrice without fluoride; MP: MI Paste; MPP: MI Paste Plus and FD: Fluoride dentifrice - 1100 ppm F as NaF). Knoop surface hardness (SH) test was performed in three stages (T0 - sound enamel, T1 - after preformed lesion, and T2 - after treatment) and the cross-sectional hardness (CSH) test was performed after treatment using a 50-gram Knoop load for 15 s. Knoop hardness number (KHN) was similar between treatments. %SHr was significantly higher in the MP, FD, and MPP when compared to CO group (Kruskal-Wallis and Mann-Whitney tests, p < 0.05). Harder enamel was found in MP (75 μm) and FD groups at 75 to 175 μm. Treatment with DF, MP, and MPP promoted an increase of 20.27%, 19.24%, and 14.71%, respectively, in Integral Hardness Change (ΔIHC) when compared to CO (p<0.05). Remineralizing agents (MP, MPP, and DF) were able to inhibit demineralization of human enamel subjected to high cariogenic challenge in situ. DF had the greatest preventive potential against the progression of carious lesions.

Tuftelin-derived peptide facilitates remineralization of initial enamel caries in vitro

With the gradual discovery of functional domains in natural proteins, several biologically inspired peptides have been designed for use as biomaterials for hard tissue regeneration and repair. In this study, we designed a tuftelin-derived peptide (TDP) and tested its effects on hydroxyapatite crystallization and remineralization of initial enamel carious lesions in vitro. Using circular dichroism spectroscopy, we found that TDP contained 36.1% β-sheets and β-turns, which could be influenced by calcium ions. We verified the ability of TDP to crystallize hydroxyapatite using transmission electron microscopy and its ability to bind to the enamel surface and hydroxyapatite using confocal laser scanning microscopy and Langmuir adsorption isotherms (K = 881.56, N = 1.41 × 10^-5 ). Artificial enamel lesions were generated on human enamel blocks and subjected to a 12-day pH cycling model and were treated with 25 μM TDP, 1 g/L sodium fluoride (NaF), or deionized water. We analyzed the results of remineralization by surface microhardness testing, polarized light microscopy, and transverse microradiography. The TDP group showed significantly higher surface microhardness recovery (49.21 ± 1.66%), shallower lesions (34.89 ± 4.05 μm), and less mineral loss (871.33 ± 81.49 vol%·μm) after pH cycling than the deionized water group (p < .05). There were no significant differences between the TDP and NaF groups. Our experiment indicated that TDP could regulate hydroxyapatite crystallization and promote remineralization of enamel caries in vitro.

Differential induction of surface chemical compositional change on tooth structure by glass ionomer restorative materials

Glass ionomer cement (GIC) is a restorative dental material capable of promoting mineral deposition on surrounding tooth substrates. However, it is unclear as to whether demineralization and remineralization due to an oral pH change of the tooth affect the dissolution pattern of tooth crown and root differently. It also remains to be elucidated how GIC alters superficial chemical compositions of tooth crown structurally known as enamel, in relation to the root. In this study, we investigated an effect of pH challenge on chemical compositional change of tooth crown and root, as well as the contribution of GIC restorations on a shift of elemental abundance on tooth crown and root. Our findings demonstrated that an exposure to a pH cycling resulted in a drastic change of elemental profile of the root, but not the crown. Modification of superficial elemental ingredients of GIC-restored cavities located on different anatomical part of the tooth was found after an acid attack. Notably, a differential induction of chemical compositional shift was dependent on the type of GIC used and the location of restored GIC. Our study highlights a susceptibility of root portion to acid-induced elemental dissolution, and that GIC use might be implicated in the delayed dissolution rate of the tooth structure.

Effect of self-assembling peptide P11-4 on orthodontic treatment-induced carious lesions

This study aimed to evaluate the effect of self-assembling peptide P11-4 (SAP) in the therapy of initial smooth surface caries (white spot lesions, WSL) following orthodontic multibracket treatment. Twenty-three patients (13f/10m; average age 15.4 years) with at least two teeth with WSL were recruited for the randomised controlled clinical trial with split-mouth design. In opposite to the control teeth, the test teeth were treated with SAP on Day 0. The primary endpoint was the impedance measurement of WSL using customised tray to ensure reproducibility of the measurement location. The secondary endpoint was the morphometric measurement of WSL using a semi-automated approach to determine the WSL size in mm2. Treatment effects were adjusted for site-specific baseline values using mixed models adapted from the cross-over design. Test WSL showed a mean baseline impedance value of 46.7, which decreased to 21.1, 18.4, and 19.7 after 45, 90, and 180 days, respectively. Control WSL showed a mean baseline value of 42.0, which decreased to 35.0, 29.5, and 33.7, respectively. The overall treatment contrast was -13.7 (95% CI: -19.6 - -7.7; p < 0.001). For the secondary endpoint, the test WSL size decreased from 8.8 at baseline to 6.5 after 180 days. The control WSL decreased from 6.8 to 5.7, respectively. The related treatment contrast was -1.0 in favour of test WSL (95% CI: -1.6 - -0.5; p = 0.004). The treatment of initial carious lesions with self-assembling peptide P11-4 leads to superior remineralisation of the subsurface lesions compared with the control teeth.

Ca2+ release and buffering effects of synthetic hydroxyapatite following bacterial acid challenge

BACKGROUND

Synthetic particulate hydroxyapatite (HAP; Ca₅(PO₄)₃(OH)) is used as ingredient in oral care products but its effects on cariogenic biofilms are not clear yet. The primary mode of action of HAP may be acting as a calcium phosphate reservoir when deposited in oral biofilms and release Ca²⁺ and (hydrogen) phosphate ions upon bacterial acid challenge. The aim of this in vitro study was to test this hypothesis by investigating release of Ca²⁺ ions and potential buffering effects from HAP upon bacterial acid challenge in planktonic cultures and biofilms of Streptococcus mutans.

METHODS

Planktonic cultures of S. mutans were grown in BHI broth with 1% sucrose or with additional 5% HAP or 5% silica for up to 48 h. Separately, biofilms of S. mutans were grown in BHI for 72 h in total. After 24 h of this biofilm culture, either BHI alone or BHI with additional 0.5% HAP or 0.5% silica was added. After 48 h, BHI with 1% sucrose was added to allow bacterial acid formation. Ca²⁺ release was determined colorimetrically and pH measurements were performed using a pH electrode. For statistical analysis, non-parametrical procedures were applied (n ≥ 10; Mann-Whitney U test; α = 0.05).

RESULTS

Relevant release of Ca²⁺ was only evident in planktonic cultures or biofilms with HAP but not in both other groups (p ≤ 0.001). In suspended biofilms with HAP, median pH was 4.77 after 72 h and about 0.5 pH units higher as compared to both other groups (4.28 or 4.32, respectively; p ≤ 0.001).

CONCLUSIONS

Under the tested conditions, synthetic HAP releases Ca²⁺ ions upon bacterial acid challenge and may also show some buffering capacity but further studies are needed to investigate whether the concentrations tested here can also be reached clinically in dental biofilms.

The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review

Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity's low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel's remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel's mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.

The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review

Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity’s low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel’s remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel’s mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.

The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review

Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity's low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel's remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel's mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.

Randomized Clinical Trial investigating Self-Assembling Peptide P11-4 for Treatment of Early Occlusal Caries

Non-invasive caries treatment is a major focus in modern dentistry. The present study was designed to evaluate the effectiveness of monomeric self-assembling peptide P₁₁-4 (SAP P₁₁-4) in combination with fluoride varnish or polymeric self-assembling peptide matrix (SAPM) in treatment of non-cavitated occlusal caries. Ninety children and adolescents were included in this randomized, gold-standard-controlled clinical trial. Test Group 1 received SAP P₁₁-4 and twice fluoride varnish at baseline and Day 180, Test Group 2 received SAP P₁₁-4 on baseline and twice weekly SAPM (home-application), and Control Group received fluoride varnish on baseline and Day 180. Caries progression was measured by laser fluorescence, Nyvad Caries Activity, ICDAS-II-codes, and investigator assessments. Laser fluorescence changes demonstrated superior results for Test Group 1 and 2, as values decreased compared to an increase for the Control Group (p < 0.0005). ICDAS-II codes at Day 360 showed partial regression for Test Group 1 (6.7%) and Test Group 2 (20.0%) and partial progression for Control Group (23.3%) (p < 0.01). Nyvad Caries Activity yielded superior caries inactivation for Test Groups, compared to Control Group (p = 0.002). This trial showed that SAP P₁₁-4, applied either in combination with fluoride varnish or twice weekly SAPM, was a superior treatment for early caries compared to fluoride varnish alone.

In Vitro Re-Hardening of Bleached Enamel Using Mineralizing Pastes: Toward Preventing Bacterial Colonization

The search for materials able to remineralize human hard tissues is a modern medical challenge. In this study, the protective effect on the enamel microhardness by a paste based on hydroxyapatite and sodium fluoride (Remin Pro) was evaluated after two different enamel bleaching procedures. Forty sound human incisors were randomly assigned to different treatments: bleaching with an in-office agent (Perfect Bleach Office+); bleaching with an at-home agent (Perfect Bleach); bleaching with the in-office agent followed by the prophylaxis paste; bleaching with the at-home agent followed by the prophylaxis paste; no treatment (control). Bleaching was performed at 0, 8, 24 and 32 h, followed by a 3-min re-mineralizing treatment in the subgroups designed to receive it. Specimens underwent a micro-hardness tester and a mean Vickers Hardness number was considered for each specimen. ANOVA exhibited significant differences among groups. Post-hoc Tukey testing showed significant micro-hardness decrease after the application of both the two bleaching agents. The treatment with prophylaxis paste significantly increased the micro-hardness values of bleached enamel.

Is there evidence for Novamin application in remineralization?: A Systematic review

Background

Calcium sodium phosphor-silicate material, a type of bio-glass was originally developed as an implant material to regenerate bone and recently adapted for use in oral care products (NovaMin Technology Inc.). Novamin is used for many dental problems like hypersensitivity, gingivitis, bleeding, non-carious lesions, carious lesions, whitening and is currently emerging as one of the treatment modality for the remineralization of the tooth. Since the prescription of these novel materials to the patients are based on cost effectiveness, efficacy and effectiveness, a clinician should make decision based on best available evidence. Hence, the objective of this review is to find out the current evidence available on the use of Novamin as an agent for remineralization.

Materials and methods

Relevant articles were searched and screened from several databases including PubMed, Cochrane review, Science Direct and trip which were published till 1988 to July 2017; The articles relevant to the objective of this review were included (RCT's) and articles out of interest of this review were excluded. The primary outcome for the chosen studies is the remineralization capacity of Novamin. Data extraction is done independently and jointly by 3 authors using data collection forms. Studies obtained were evaluated using the Cochrane Collaboration tools for accessing risk bias. The assessment of the quality of the evidence and the bias risk was obtained using the Grading of Recommendations Assessment Development and evaluation System.

Results

The articles from the database obtained for further review was N = 1. According to the study reviewed, the baseline comparisons using decalcification index obtained between Novamin study group (ReNew) and the control group (Crest) yield a P-value of 0.97 whereas after a 3 months interval follow up the value is 0.0403 suggesting there was a trend towards improvement in white spot lesions in the control group and at 6 months' time point the p-value is 0.81 concluding that there are no significant difference of remineralization process obtained by using traditional toothpaste and Novamin.

Conclusion

Review shows that Novamin has significantly less clinical evidence to prove its effectiveness as a remineralization agent in treating both carious and non-carious lesion. Hence, better designed clinical trials should be carried out in the future before definitive recommendations can be made.

Comparative efficacy of a hydroxyapatite and a fluoride toothpaste for prevention and remineralization of dental caries in children

Objective

This in situ study compared the effectiveness of two toothpastes containing hydroxyapatite or 500 ppm fluoride in promoting remineralization and inhibiting caries development.

Materials and methods

Two enamel blocks (human primary teeth), one sound and one with artificially-produced caries lesion, were exposed to toothpaste containing either 10% hydroxyapatite or 500 ppm F⁻ (amine fluoride) via intra-oral appliance worn by 30 adults in two-arm double blind randomized crossover study lasting 14 days per arm (ClinicalTrials.gov: NCT03681340). Baseline and post-test mineral loss and lesion depth (LD) were quantified using microradiography. One-sided t-test of one group mean was used for intragroup comparison (baseline vs. post-test), while two-sided t-test of two independent means was used to compare the two toothpaste groups.

Results

Pairwise comparison (baseline vs. test) indicated significant (p < 0.0001) remineralization and LD reduction by either toothpaste; however, when compared against each other, there was no statistically significant difference in remineralization or LD reduction between the two toothpastes. No demineralization could be observed in sound enamel blocks exposed to either toothpaste. While F⁻ induced lesion surface lamination, HAP produced a more homogenous lesion remineralization.

Conclusions

10% hydroxyapatite achieved comparable efficacy with 500 ppm F⁻ in remineralizing initial caries and preventing demineralization. Thus the HAP toothpaste is confirmed to be equal to the fluoride toothpaste in this study.

Bioactive Glass Applications in Dentistry

At present, researchers in the field of biomaterials are focusing on the oral hard and soft tissue engineering with bioactive ingredients by activating body immune cells or different proteins of the body. By doing this natural ground substance, tissue component and long-lasting tissues grow. One of the current biomaterials is known as bioactive glass (BAG). The bioactive properties make BAG applicable to several clinical applications involving the regeneration of hard tissues in medicine and dentistry. In dentistry, its uses include dental restorative materials, mineralizing agents, as a coating material for dental implants, pulp capping, root canal treatment, and air-abrasion, and in medicine it has its applications from orthopedics to soft-tissue restoration. This review aims to provide an overview of promising and current uses of bioactive glasses in dentistry.

Remineralization, Regeneration, and Repair of Natural Tooth Structure: Influences on the Future of Restorative Dentistry Practice

Currently, the principal strategy for the treatment of carious defects involves cavity preparations followed by the restoration of natural tooth structure with a synthetic material of inferior biomechanical and esthetic qualities and with questionable long-term clinical reliability of the interfacial bonds. Consequently, prevention and minimally invasive dentistry are considered basic approaches for the preservation of sound tooth structure. Moreover, conventional periodontal therapies do not always ensure predictable outcomes or completely restore the integrity of the periodontal ligament complex that has been lost due to periodontitis. Much effort and comprehensive research have been undertaken to mimic the natural development and biomineralization of teeth to regenerate and repair natural hard dental tissues and restore the integrity of the periodontium. Regeneration of the dentin-pulp tissue has faced several challenges, starting with the basic concerns of clinical applicability. Recent technologies and multidisciplinary approaches in tissue engineering and nanotechnology, as well as the use of modern strategies for stem cell recruitment, synthesis of effective biodegradable scaffolds, molecular signaling, gene therapy, and 3D bioprinting, have resulted in impressive outcomes that may revolutionize the practice of restorative dentistry. This Review covers the current approaches and technologies for remineralization, regeneration, and repair of natural tooth structure.