Treatment of Carious Lesions Using Self-Assembling Peptides

Surface porosity of enamel white spot lesions and penetration of fluorapatite nanocrystals into their subsurface: proof-of-concept study

OBJECTIVES

In this study, we used atomic force microscopy (AFM) to quantify the size of surface pore apertures of enamel white spot lesions and then demonstrated the penetration of fluorapatite nanocrystals (nFA) into the subsurface of these lesions.

METHODS

For the porosity study, enamel lesions were created on three sound human teeth using a demineralizing gel for 8 days. The interface between sound enamel and the artificial lesion was analyzed by AFM. To visualize the penetration of nFA tagged with a calcium-binding fluorophore (Fluo-4) into the subsurface of white spot lesions, we used two-photon microscopy. Sixteen extracted human teeth with either active, natural, or in vitro-created carious lesions in enamel were randomly divided into three groups. The teeth were treated for 2 min with either a suspension of tagged nFA crystals, Fluo-4 alone, or deionized water, and left for 30 min before being washed with distilled water and examined microscopically.

RESULTS

A greater concentration of surface pores with larger areas was observed on the in vitro demineralized enamel (29 % of pores greater than 1.0 µm2) when compared with the adjacent sound enamel (8 % of pores greater than 1.0 µm2) (p=0.012, Fisher exact test). In vitro and natural lesions treated with tagged nFA showed fluorescence at depths ranging from 50 to 170 µm, demonstrating penetration of the nFA into the lesion subsurface. The lesions treated with Fluo-4 alone with no crystals showed mostly surface fluorescence (restricted to the outer 25 µm), while those treated with deionized water showed minimal (restricted to the outer 20 µm) to no fluorescence.

CONCLUSION

We have demonstrated the use of AFM to quantify the surface pore apertures and two-photon microscopy to visualize nFA crystals in the subsurface of non-cavitated enamel lesions.

CLINICAL SIGNIFICANCE

The restoration of the subsurface of non-cavitated caries lesions is a clinical challenge. This study demonstrated that a 2 min application of nFA could penetrate through the surface apertures of non-cavitated enamel lesions into their subsurface.

Oral Microbiome: A Review of Its Impact on Oral and Systemic Health

PURPOSE OF REVIEW

This review investigates the oral microbiome's composition, functions, influencing factors, connections to oral and systemic diseases, and personalized oral care strategies.

RECENT FINDINGS

The oral microbiome is a complex ecosystem consisting of bacteria, fungi, archaea, and viruses that contribute to oral health. Various factors, such as diet, smoking, alcohol consumption, lifestyle choices, and medical conditions, can affect the balance of the oral microbiome and lead to dysbiosis, which can result in oral health issues like dental caries, gingivitis, periodontitis, oral candidiasis, and halitosis. Importantly, our review explores novel associations between the oral microbiome and systemic diseases including gastrointestinal, cardiovascular, endocrinal, and neurological conditions, autoimmune diseases, and cancer. We comprehensively review the efficacy of interventions like dental probiotics, xylitol, oral rinses, fluoride, essential oils, oil pulling, and peptides in promoting oral health by modulating the oral microbiome.

SUMMARY

This review emphasizes the critical functions of the oral microbiota in dental and overall health, providing insights into the effects of microbial imbalances on various diseases. It underlines the significant connection between the oral microbiota and general health. Furthermore, it explores the advantages of probiotics and other dental care ingredients in promoting oral health and addressing common oral issues, offering a comprehensive strategy for personalized oral care.

Evaluation of the remineralization potential of self-assembling peptide P11-4 with fluoride compared to fluoride varnish in the management of incipient carious lesions: a randomized controlled clinical trial

OBJECTIVES

The present trial's aim was to compare the remineralization potential of self-assembling peptide P11-4 combined with fluoride to that of fluoride varnish.

MATERIALS AND METHODS

Twenty-eight participants with 58 incipient carious lesions were enrolled in the present trial. Participants were randomly divided into two groups with 14 participants and 29 incipient lesions in each group. Patients were assigned either to self-assembling peptide combined with fluoride (Curodont Repair Fluoride Plus™) or sodium fluoride varnish (NaF, Bifluorid 10) groups. Both agents were applied according to the manufacturer's instructions on non-cavitated incipient carious lesions. Lesions were assessed by two calibrated and blinded assessors at baseline, and after one-, three- and six-months using a laser fluorescence device (DIAGNOdent).

RESULTS

Although laser fluorescence scores significantly improved in both groups over time (p < 0.05), no notable differences were evident between both groups at one-month (p > 0.05). Yet, at three- and six-months statistically lower laser fluorescence readings were evident in the self-assembling peptide combined with fluoride group in comparison to the fluoride alone group (p < 0.05). There was 60% less risk for caries progression for Curodont Repair Fluoride Plus™ when compared to NaF varnish after six months. Self-assembling peptide combined with fluoride was able to change 65.5% of non-cavitated carious lesions from DIAGNOdent score 3 (11-20) to score 1 (0-4). Fluoride varnish was able to change 13.8% of the lesions from score 3 to score 1 after six months.

CONCLUSIONS

The self-assembling peptide combined with fluoride varnish showed higher remineralization potential than fluoride varnish alone for incipient carious lesions over a six-months follow up.

CLINICAL RELEVANCE

The combination of self-assembling peptide P11-4 and fluoride could offer a new tool in managing incipient carious lesions.

White Spot Lesions in Fixed Orthodontics: A Literature Review on Etiology, Prevention, and Treatment

White spot lesions (WSLs) are a common complication after treatment using fixed orthodontic appliances. Decalcification of enamel surrounding fixed orthodontic appliances, known as WSLs, poses a significant aesthetic difficulty during and after treatment, as the purpose of fixed orthodontic therapy is to improve facial and dental appearance. Modern dentistry utilizes remineralization therapies to non-invasively treat WSLs to prevent the progression of disease and enhance the strength, appearance, and functionality of the affected tooth. This review aims to identify and assess the etiology, formation, and risk factors, as well as current treatment approaches used in achieving WSLs remineralization, induced by fixed orthodontic appliances. An electronic search on the PubMed and ScienceDirect databases was performed using a selected keyword. A total of 172 studies (from 2013 to 2023) were retrieved. Their references were also checked to find other relevant studies. Duplicate copies were excluded. After the abstract and full-text screening, only 39 studies were included. Even though numerous studies address the different treatment modalities for managing post-orthodontic WSLs, such as antiseptics; fluorides such as dentifrices, mouthwash, and varnish, and remineralizing agents such as casein phosphopeptides amorphous calcium phosphate, biomimetic self-assembling peptides, lasers, bleaching, microabrasion, and resin infiltration. There is a lack of evidence-based studies that examine the long-term effects of WSL treatment. Further well-performed controlled clinical trials with long-term follow-up are needed to establish best clinical practice.

Biomimetic Remineralization of Artificial Caries Lesions with a Calcium Coacervate, Its Components and Self-Assembling Peptide P11-4 In Vitro

The application of calcium coacervates (CCs) may hold promise for dental hard tissue remineralization. The aim of this study was to evaluate the effect of the infiltration of artificial enamel lesions with a CC and its single components including polyacrylic acid (PAA) compared to that of the self-assembling peptide P11-4 in a pH-cycling (pHC) model. Enamel specimens were prepared from bovine incisors, partly varnished, and stored in demineralizing solution (DS; pH 4.95; 17 d) to create two enamel lesions per sample. The specimens were randomly allocated to six groups (n = 15). While one lesion per specimen served as the no-treatment control (NTC), another lesion (treatment, T) was etched (H3PO4, 5 s), air-dried and subsequently infiltrated for 10 min with either a CC (10 mg/mL PAA, 50 mM CaCl2 (Ca) and 1 M K2HPO4 (PO4)) (groups CC and CC + DS) or its components PAA, Ca or PO4. As a commercial control, the self-assembling peptide P11-4 (CurodontTM Repair, Credentis, Switzerland) was tested. The specimens were cut perpendicularly to the lesions, with half serving as the baseline (BL) while the other half was exposed to either a demineralization solution for 20 d (pH 4.95; group CC + DS) or pHC for 28 d (pH 4.95, 3 h; pH 7, 21 h; all five of the other groups). The difference in integrated mineral loss between the lesions at BL and after the DS or pHC, respectively, was analyzed using transversal microradiography (ΔΔZ = ΔZpHC - ΔZbaseline). Compared to the NTC, the mineral gain in the T group was significantly higher in the CC + DS, CC and PAA (p < 0.05, Wilcoxon). In all of the other groups, no significant differences between treated and untreated lesions were detected (p > 0.05). Infiltration with the CC and PAA resulted in a consistent mineral gain throughout the lesion body. The CC as well as its component PAA alone promoted the remineralization of artificial caries lesions in the tested pHC model. Infiltration with PAA further resulted in mineral gain in deeper areas of the lesion body.

Efficacy of Self-assembling Peptide P11-4 in Remineralizing In Vitro Caries-like Lesions in Primary Enamel Samples in Combination with Calcium Phosphate-based Remineralization Agents

Aims and background

The efficacy of self-assembling peptide P11-4 in combination with calcium-phosphate-based remineralization agents in remineralizing caries-like lesions in primary enamel was evaluated using a 21-day pH cycling experiment by Vickers microhardness [Vickers hardness number (VHN)] and scanning electron microscopy (SEM).

Materials and methods

A total of 120 primary enamel samples were made to undergo a demineralization cycle to produce caries-like lesions. They were divided into six groups, namely negative control (NC), positive control (P11-4), and four interventional groups in which each of the following calcium-phosphate-based agents were used in combination with P11-4-calcium sucrose phosphate (CSP), bioactive glass (BG), casein phosphopeptides, and casein phosphopeptides with fluoride. A 21-day pH cycling experiment was carried out with alternating demineralization and remineralization phases. The enamel samples were analyzed at baseline, post production of caries-like lesions, and post 21-day pH cycling using Vickers microhardness and SEM. Results were statistically analyzed using repeated measures of analysis of variance (ANOVA), keeping the level of significance at 0.05.

Results

Supplementing P11-4 with calcium-phosphate-based agents improved the surface hardness of the demineralized primary enamel samples, among which the fluoridated milk protein-based remineralization agent yielded a statistically significant improvement.

Conclusion

P11-4 promoted the regeneration of incipient caries-like lesions. However, there is added benefit when this peptide is used in combination with a fluoridated calcium-phosphate-based agent.

Clinical significance

This study would help the clinician compose an effective regimen for the patient to follow at home posttreatment with P11-4, in-office treatment.

How to cite this article

Krishnamoorthi A, Shanbhog RS, Godhi BS, et al. Efficacy of Self-assembling Peptide P11-4 in Remineralizing In Vitro Caries-like Lesions in Primary Enamel Samples in Combination with Calcium Phosphate-based Remineralization Agents. Int J Clin Pediatr Dent 2024;17(5):552-557.

Effect of calcium-coacervate infiltration of artificial enamel caries lesions in de- and remineralizing conditions

OBJECTIVES

Calcium-coacervate emulsions (CC) might be considered as mineral precursors to foster remineralization of carious dental hard tissues. This study analyzed the instant effect of repeated infiltration of artificial caries lesions with a CC emulsion as well as the effects of subsequent exposure of CC-infiltrated lesions to demineralizing and remineralizing environments.

METHODS

Bovine enamel specimens were partly covered with varnish to leave three exposed windows. Artificial enamel caries lesions were created (pH 4.95, 17d). Baseline controls (BL) were obtained by preparing a thin section of each specimen. Specimens were allocated to five groups. In three groups lesions were etched with 37 % phosphoric acid gel, infiltrated with dipotassium hydrogen phosphate and subsequently with a calcium coacervate emulsion, prepared by mixing CaCl2 ⋅ 2H2O with polyacrylic acid sodium salt (PAA-Na). Subsequently, the infiltration effect was either analyzed immediately (Inf.) or after exposition to either de- (Inf.+DS) or remineralizing solution (Inf.+RS) for 10 or 20 days, respectively. In two control groups specimens were exposed to either DS or RS, respectively without prior CC infiltration. Integrated mineral loss [ΔZ(vol%×µm)] was analyzed using transverse microradiography (TMR).

RESULTS

Infiltration of enamel caries lesions with coacervate solution resulted in only subtle immediate mineral gain even if repeated. When exposed to demineralizing conditions, infiltrated lesions showed significantly less mineral loss compared to untreated controls (p < 0.05; Kruskal Wallis) and exhibited characteristic mineral depositions within the lesion body.

CONCLUSIONS

While immediate mineral gain by infiltration was only modest, the CC-emulsion might be able to prevent demineralization in acidic conditions.

CLINICAL SIGNIFICANCE

Calcium coacervates might act protective against further demineralization when infiltrated into enamel caries lesions.

Combined Effect of a Bioinspired Self-Assembling Peptide and Fluoride Varnish on Remineralisation of Artificial Early Enamel Caries Lesion: An in vitro Study

INTRODUCTION

This study aimed to investigate the remineralisation effect of combined use of a bioinspired self-assembling peptide (P26) and fluoride varnish on artificial early enamel caries lesions.

METHODS

Bovine enamel blocks with artificial early enamel caries lesions were prepared. The blocks were randomly allocated to four experimental groups to receive the following treatments: A = P26 + fluoride varnish, B = P26, C = fluoride varnish, and D. distilled water (negative control). The treated blocks were subjected to pH cycling. Enamel blocks were collected at time points of 7 days (d7) and 21 days (d21). The mineral gain, elemental analysis and crystal characteristics of the caries lesion were assessed by micro-computed tomography, scanning electron microscopy with energy dispersive X-ray and X-ray diffraction (XRD), respectively.

RESULTS

The mean ± standard deviation of mineral gain of group A to D were 17.4 ± 4.2%, 10.7 ± 2.2%, 10.1 ± 1.2%, and 6.8 ± 0.5% at d7, respectively, and 15.2 ± 2.6%, 8.7 ± 3.1%, 9.7 ± 1.2%, and 7.8 ± 2.3% at d21, respectively. A significant higher mineral gain was observed in group A when compared to other groups at both d7 and d21 (p < 0.05). The calcium-to-phosphate ratio remained consistent across all groups, ranging between 1.2 and 1.4. XRD analysis indicated that crystal composition on the surfaces was apatite for all groups.

CONCLUSION

In conclusion, the present study provided a first indication of better remineralisation effects of the combined use of the bioinspired self-assembling peptide P26 and fluoride varnish compared to the effects of the respective individual uses of P26 or fluoride varnish.

Remineralization effects of enamel binding peptide, WGNYAYK, on enamel subsurface demineralization in vitro. Enamel binding peptide, WGNYAYK effect remineralization of enamel

Objectives: We investigated remineralization effects of enamel binding peptide (EBP), WGNYAYK, on enamel subsurface demineralization in vitro.Methods: Bovine lower incisor crowns were used as subsurface enamel demineralization samples, and changes of EBP binding, remineraliztion rate, hardness and microstructure were investigated. Binding of EBP, remineralization rate, hardness and structural changes were investigated. Fluorescein isothiocyatate (FITC)-labeled EBPs (0.4 mM, 4.0 mM, and 7.0 mM) were applied to the samples for 30 min at 37 °C, with sample surfaces and cross-sections observed by confocal laser scanning microscope (CLSM). Mineralization analysis samples were divided into 4 experimental groups; distilled water (DW), EBP 0.4 mM, EBP 4.0 mM, and EBP 7.0 mM. Mineral density changes were measured by micro-CT with hardness measured by nano-indentation. Samples were also observed by scanning electron microscope (SEM) for surface and longitudinal microstructure.

Results

CLSM images indicated that increased fluorescence was observed in the surface layer and up to about 20 μm below the surface layer. The remineralization rate was significantly higher for EBP 7.0 mM compared to DW (p = 0.008). Enamel surface hardness was significantly higher in all EBP groups compared to DW (p < 0.05) and was highest in the 7.0 mM group. SEM images showed obscuring of the superficial columnar structure in the 7.0 mM EBP group, indicating subsurface crystalline structure recovery.

Conclusion

The results of this study suggest that EBP binds to demineralized enamel and promotes remineralization.

Framework for fiscal impact analysis of managing initial caries lesions with noninvasive therapies

BACKGROUND

Evidence-based noninvasive caries therapies for initial caries lesions are available in the United States. Fundamental differences between noninvasive therapies and the traditional surgical dental approach warrant a study of the financial scalability.

METHODS

The financial costs and benefits of fee-for-service clinics and payors were compared across 11 scenarios simulating the treatment of 1,000 initial caries lesions during a 3-year period. The scenarios included varying combinations of noninvasive therapies (that is, silver diamine fluoride, self-assembling peptide P11-4, and glass ionomer therapeutic sealants), no treatment, and various rates of 1- through 3-surface restorations to an estimated 2022 practice model. We used a decision tree microsimulation model for deterministic and probabilistic sensitivity analyses. We derived assumptions from an initial lesion and noninvasive therapy-focused cohort study with operations data from 16 sites accepting Medicaid in Alabama as a case study and clinical data from all 92 sites.

RESULTS

In comparison with the 2022 practice model assumed for this study, scenarios that produce mutually beneficial results for payors' savings and clinics' net profits and profit margins include self-assembling peptide P11-4, silver diamine fluoride on nonesthetic surfaces, and a mix of 3 noninvasive therapies. When considering the limited resources of chair and clinician time, the same scenarios, as well as silver diamine fluoride with restorations, emerged with substantially higher clinic net profit.

CONCLUSIONS

Hypothetical scenarios that include noninvasive therapies and minimize restorations achieve improved outcomes for all parties.

PRACTICAL IMPLICATIONS

Payors and clinicians should explore and implement noninvasive caries therapies to improve oral health for all. This study was registered at ClinicalTrials.gov. The registration number is NCT04933331.

Biomimetic Enamel Regeneration Using Self-Assembling Peptide P11-4

The recent understanding of the etiology and pathology of dental caries has shifted its treatment from invasive drill and fill conventional strategies to noninvasive and/or minimally invasive approaches. Guided tissue regeneration (GTR) is a well-established therapeutic approach in medicine and periodontal and oral surgery. Recently, the concept of biomimetic regeneration has been further expanded to treat the loss of hard dental tissues. Self-assembling peptides have emerged as a promising biomaterial for biomimetic regeneration due to their ability to construct a protein scaffold in the body of early carious lesions and provide a matrix that promotes remineralization. This review article accompanies the development of self-assembling peptide P11-4 for the treatment of initial carious lesions. In vitro and in vivo studies on the safety, clinical applicability, and efficacy of P11-4 are discussed. Furthermore, different treatment options and potential areas of application are presented.

Comparative Evaluation of Antimicrobial Efficacy of Fluoride-Based and Self-Assembling Peptide P11-4-based Tooth Remineralization Agents on Streptococcus mutans: A Microbiological Study

Background

Dental caries is a biofilm-related oral disease that continues to afflict the majority of the world's population. The disease results from an interaction between specific bacteria and dietary constituents within a biofilm known as dental plaque. Among the cariogenic microorganisms, Streptococcus mutans (S. mutans) plays pivotal role in caries-inducing processes.

Objectives

Evaluate and compare the antimicrobial efficacy of self-assembling peptide P11-4-based tooth remineralization agents on S. mutans.

Materials and Methods

An in vitro microbiological study. The antibacterial efficacy of self-assembling peptide P11-4 gel (Group 1), fluoride enhanced hydroxyapatite gel (Group 2), acidulated phosphate fluoride gel (Group 3), chlorhexidine gluconate gel 1.0% w/w (Group 4; positive control), and normal saline (Group 5; negative control) was performed using time-kill assay over a period of 24 h and the number of S. mutans colony-forming units (CFUs) were calculated.

Statistical Analysis

Statistical analysis was done using Kruskal-Wallis test and Mann-Whitney post hoc Test. The level of significance was set at P < 0.05.

Results

Group 1 showed mean CFUs (× 103) of 841.33 ± 3.51, Group 2 showed 10035.33 ± 60.68, Group 3 showed 1058.00 ± 56.96, Group 4 showed 0.00 ± 0.00, and Group 5 showed mean CFUs with 15226.67 ± 96.67. The difference in the mean CFUs (× 103) between different groups was statistically significant at P < 0.001.

Conclusion

The self-assembling peptide P11-4-based tooth remineralization agent exhibited an inhibitory influence on S. mutans and hence formation of cariogenic bacteria dominant biofilm can thus be affected by its application.

Bioactive Materials for Caries Management: A Literature Review

Researchers have developed novel bioactive materials for caries management. Many clinicians also favour these materials, which fit their contemporary practice philosophy of using the medical model of caries management and minimally invasive dentistry. Although there is no consensus on the definition of bioactive materials, bioactive materials in cariology are generally considered to be those that can form hydroxyapatite crystals on the tooth surface. Common bioactive materials include fluoride-based materials, calcium- and phosphate-based materials, graphene-based materials, metal and metal-oxide nanomaterials and peptide-based materials. Silver diamine fluoride (SDF) is a fluoride-based material containing silver; silver is antibacterial and fluoride promotes remineralisation. Casein phosphopeptide-amorphous calcium phosphate is a calcium- and phosphate-based material that can be added to toothpaste and chewing gum for caries prevention. Researchers use graphene-based materials and metal or metal-oxide nanomaterials as anticaries agents. Graphene-based materials, such as graphene oxide-silver, have antibacterial and mineralising properties. Metal and metal-oxide nanomaterials, such as silver and copper oxide, are antimicrobial. Incorporating mineralising materials could introduce remineralising properties to metallic nanoparticles. Researchers have also developed antimicrobial peptides with mineralising properties for caries prevention. The purpose of this literature review is to provide an overview of current bioactive materials for caries management.

Peptides in Dentistry: A Scoping Review

Currently, it remains unclear which specific peptides could be appropriate for applications in different fields of dentistry. The aim of this scoping review was to scan the contemporary scientific papers related to the types, uses and applications of peptides in dentistry at the moment. Literature database searches were performed in the following databases: PubMed/MEDLINE, Scopus, Web of Science, Embase, and Scielo. A total of 133 articles involving the use of peptides in dentistry-related applications were included. The studies involved experimental designs in animals, microorganisms, or cells; clinical trials were also identified within this review. Most of the applications of peptides included caries management, implant osseointegration, guided tissue regeneration, vital pulp therapy, antimicrobial activity, enamel remineralization, periodontal therapy, the surface modification of tooth implants, and the modification of other restorative materials such as dental adhesives and denture base resins. The in vitro and in vivo studies included in this review suggested that peptides may have beneficial effects for treating early carious lesions, promoting cell adhesion, enhancing the adhesion strength of dental implants, and in tissue engineering as healthy promotors of the periodontium and antimicrobial agents. The lack of clinical trials should be highlighted, leaving a wide space available for the investigation of peptides in dentistry.

Comparative Efficacy of Novel Biomimetic Remineralising Technologies

Biomimetic technologies for the remineralisation of enamel subsurface lesions (ESLs) have been developed and include: fluorocalcium phosphosilicate bioglass (BG/F); casein phosphopeptide-amorphous calcium phosphate (CPP−ACP) and with fluoride (CPP−ACFP); and self-assembling oligopeptide P11-4 (SAP). The aim of this study was to compare the remineralisation of ESLs in vitro using these technologies. Human enamel slabs with ESLs were cut into two half-slabs; one half-slab was untreated (control), and the other half was treated by exposure to one of the four technologies with artificial saliva (AS) or AS alone for 14 days at 37 °C. The technologies were applied to the ESL surface according to the manufacturer’s instructions. At the completion of each treatment, the treated half-slabs and their paired control half-slabs were embedded, sectioned and the mineral content was determined using transverse microradiography. The change in mineral content (remineralisation) between treatments was statistically analysed using one-way ANOVA. The order from highest to lowest remineralisation was CPP−ACFP (52.6 ± 2.6%) > CPP−ACP (43.0 ± 4.9%) > BG/F (13.2 ± 2.5%) > SAP (5.8 ± 1.6%) > AS (2.1 ± 0.5%). Only CPP−ACFP and CPP−ACP produced remineralisation throughout the body of the lesions. All four biomimetic technologies had some effect on the remineralisation of ESLs; however, CPP−ACFP with calcium, phosphate and fluoride ions stabilised by CPP was superior in the level and pattern of remineralisation obtained.

Evaluation of the remineralizing effect of biomimetic self-assembling peptides in post-orthodontic white spot lesions compared to fluoride-based delivery systems: randomized controlled trial

OBJECTIVES

To evaluate the clinical performance of self-assembling peptides versus fluoride-based delivery systems in post-orthodontic white spot lesions.

MATERIALS AND METHODS

The participants were randomly assigned into two groups (n = 58) according to the remineralizing agent used, where (A) group represented participants receiving a varnish containing 22.600 fluoride ppm and tricalcium phosphate, while the second group (B) represented participants receiving self-assembling peptide. The remineralizing process of the white spot lesion was assessed using the DIAGNOdent pen and ICDAS scoring system according to the time when the remineralizing agent was used (T), where T0 represented the score taken at baseline. T1 represented the score taken after 3 months of follow-ups and T2 score represented the score taken after 6 months of follow-up. Data were collected and statistically analyzed. The parametric data: two-way ANOVA was used to test the effect of interaction among different variables. The non-parametric data: Mann-Whitney test was used. The significance level was set at p ≤ 0.05.

RESULTS

There was a quantitative statistically significant difference via DIAGNOpen readings between Group A (fluoride material) and Group B (self-assembling peptides). The highest mean value of 10.51 was found in Group A, while the least mean value of 6.45 was found in Group B. Besides, there was a significant difference in each group concerning the time factors T0, T1, and T2 groups where (p < 0.001. As for the qualitative results concerning the ICDAS score, there was no significant difference between the two groups along with the follow-up periods T0, T1, and T2 where the p value is equal to 0.064, 0.087, and 0.277 respectively.

CONCLUSIONS

The visual assessment using ICDAS reveals that the biomimetic remineralization using self-assembling peptides and the fluoride-based varnish material showed a similar effect in masking post-orthodontic white spot lesions. However, the laser fluorescence using DIAGNOpen showed that the self-assembling peptides reveal higher performance in subsurface remineralization than the fluoride-based varnish material. Therefore, self-assembling peptides are considered a promising material for lesion regression in post-orthodontics white spot lesions.

CLINICAL RELEVANCE

Self-assembling peptide SAP-14 is a new approach to reverse and mask off post-orthodontics white spot lesions.

Self-assembling peptide-laden electrospun scaffolds for guided mineralized tissue regeneration

OBJECTIVES

Electrospun scaffolds are a versatile biomaterial platform to mimic fibrillar structure of native tissues extracellular matrix, and facilitate the incorporation of biomolecules for regenerative therapies. Self-assembling peptide P11-4 has emerged as a promising strategy to induce mineralization; however, P11-4 application has been mostly addressed for early caries lesions repair on dental enamel. Here, to investigate P11-4's efficacy on bone regeneration, polymeric electrospun scaffolds were developed, and then distinct concentrations of P11-4 were physically adsorbed on the scaffolds.

METHODS

P11-4-laden and pristine (P11-4-free) electrospun scaffolds were immersed in simulated body fluid and mineral precipitation identified by SEM. Functional groups and crystalline phases were analyzed by FTIR and XRD, respectively. Cytocompatibility, mineralization, and gene expression assays were conducted using stem cells from human exfoliated deciduous teeth. To investigate P11-4-laden scaffolds potential to induce in vivo mineralization, an established rat calvaria critical-size defect model was used.

RESULTS

We successfully synthesized nanofibrous (∼ 500 nm fiber diameter) scaffolds and observed that functionalization with P11-4 did not affect the fibers' diameter. SEM images indicated mineral precipitation, while FTIR and XRD confirmed apatite-like formation and crystallization for P11-4-laden scaffolds. In addition, P11-4-laden scaffolds were cytocompatible, highly stimulated cell-mediated mineral deposition, and upregulated the expression of mineralization-related genes compared to pristine scaffolds. P11-4-laden scaffolds led to enhanced in vivo bone regeneration after 8 weeks compared to pristine PCL.

SIGNIFICANCE

Electrospun scaffolds functionalized with P11-4 are a promising strategy for inducing mineralized tissues regeneration in the craniomaxillofacial complex.

Advanced materials for enamel remineralization

Dental caries, a chronic and irreversible disease caused by caries-causing bacteria, has been listed as one of the three major human diseases to be prevented and treated. Therefore, it is critical to effectively stop the development of enamel caries. Remineralization treatment can control the progression of caries by inhibiting and reversing enamel demineralization at an early stage. In this process, functional materials guide the deposition of minerals on the damaged enamel, and the structure and hardness of the enamel are then restored. These remineralization materials have great potential for clinical application. In this review, advanced materials for enamel remineralization were briefly summarized, furthermore, an outlook on the perspective of remineralization materials were addressed.

Management of white spot lesions induced during orthodontic treatment with multibracket appliance: a national-based survey

OBJECTIVES

The study aimed to survey current strategies against enamel demineralization during multibracket therapy (MBT) and guide a prevention concept based on existing scientific evidence.

MATERIALS AND METHODS

The survey comprised questions on the prevention and management of white spot lesions (WSL). The questionnaire was sent via email to orthodontists working in practices and universities throughout Germany. The analysis involved descriptive statistics using the chi-square test (p < 0.05).

RESULTS

A prevention protocol was used before MBT by 80.6% of the participants. Less than a quarter of the participants regularly applied topical fluoride (gel or varnish) during MBT. According to the respondents' assessment, the prevalence of WSL during MBT is 11.6%, mainly observed in 12- to 15-year-old male patients. Orthodontists graduating after 2000 tended to recommend and apply fluoride-containing materials more often than their senior colleagues (p = 0.039). Participants from private practices applied fluoride varnish or gel more frequently than those from university clinics (p = 0.013). Fluoridation was the most common (70.7%) treatment for WSL after MBT, followed by resin infiltration (21.2%). The majority (80.9%) of the participants favor a guideline for preventing WSL.

CONCLUSIONS

WSL prevention during MBT is challenging. Males in puberty are predominantly affected. Younger orthodontists are more concerned about the prevention of WSL during MBT.

CLINICAL RELEVANCE

The non-negligible prevalence of individuals with WSL emphasizes the need for dental education and health care reform. This would help to implement standardized procedures and establish innovative applications.

Effect of a Self-Assembly Peptide on Surface Roughness and Hardness of Bleached Enamel

After bleaching, enamel surfaces are damaged, contributing to erosion and tooth sensitivity. Although fluoride is used after bleaching to try and revert alterations, it is not capable of repairing tooth structure. This study compared the effect of a self-assembly peptide (P11-4), with and without fluoride, and sodium fluoride (NaF 2%) on the Knoop microhardness (KHN) and surface roughness (Ra (μm)) of bleached enamel with an in-office bleaching regimen. Enamel blocks of bovine teeth (5 × 5 × 2 mm) with standardized surface hardness were bleached with 35% carbamide peroxide, following the manufacturer’s instructions. The teeth were randomly divided into the following groups (n = 7) according to post-bleaching treatment: no treatment (negative control) (C-); 2% NaF (NaF); Curodont™ Repair (Repair); and Curodont™ Protect (Protect). Specimens were stored in artificial saliva at 37 °C. To evaluate the effect of the post-bleaching treatments, KHN and Ra were measured before bleaching (baseline) and 24 h and 7 days after bleaching. Data were submitted to repeated measures ANOVA and Bonferroni tests (α = 0.05). There were significant interactions between the study factors (p = 0.001). After 7 days, Repair (572.50 ± 79.04) and Protect (583.00 ± 74.76) specimens showed increased surface KHN, with values higher than the NaF (465.50 ± 41.50) and C- (475.22 ± 58.95) baseline values. There was no significant difference in KHN at 24 h among groups (p = 0.587). At 24 h after bleaching, Repair was significantly different from all groups (p < 0.05). Repair showed the lowest Ra (μm) values (0.133 ± 0.035). After seven days, there was no significant difference in Ra values among groups when compared to the baseline. The use of P11-4-based materials after bleaching resulted in the fastest recovery to baseline enamel properties.

The Effect of MI Varnish™ on Caries Increment and Dietary Habits among 6- and 12-Year-Old Children in Riga, Latvia: A 3-Year Randomized Controlled Trial

Aims: This randomized controlled trial investigated the effect of MI Varnish™ (5% NaF/CPP-ACP) on caries increment in 6- and 12-year-old children in Riga, Latvia within 36 months. Methods: Forty-eight 6-year-old children (Group 1) and forty-seven 12-year-old children (Group 3) received quarterly varnish application, while forty-eight 6-year-old children (Group 2) and thirty-seven 12-year-old children (Group 4) did not have varnish applied. All children/parents received the same preventive advice. All children were visually examined using ICDAS-II criteria. Questionnaires on dietary habits were completed by the children/parents at baseline and after 36 months. DMFS and dfs were calculated from ICDAS data. The statistical analysis was performed (α = 0.05) using a Chi-squared test, paired t-test (Welch test) and the Pearson correlation coefficient. The trial registration number is ISRCTN10584414. Results: In Group 1 versus Group 2, the DMFS(SD) (Baseline/36 months) values were 5.02(5.85)/13.21(6.67) (p < 0.001) versus 2.65(4.54)/10.81(6.14) (p < 0.001), respectively; the dfs(SD) (Baseline/36 months) values were 36.75(12.96)/24.04(12.9) (p < 0.001) versus 33.67(12.74)/23.88(11.91) (p < 0.001), respectively. In Group 3 versus Group 4, the DMFS(SD) (Baseline/36 months) values were 48.62(23.18)/70.96(23.28) (p < 0.001) versus 34.73(17.99)/54.95(16.09) (p < 0.001), respectively; the dfs(SD) (Baseline/36 months) values were 1.7(4.4)/0 (p < 0.05) versus 2(6.39)/0 (p = 0.06), respectively. The prevalence of caries (dfs + DMFS) decreased by 4.52 (p < 0.001) and 1.63 (p < 0.001) in Groups 1 and 2, respectively, but increased by 20.64 (p < 0.001) and 18.22 (p < 0.001) in Groups 3 and 4, respectively. An analysis of the questionnaires indicated the habitual, frequent consumption of a sugary diet by all the children. A significant correlation (r = 0.321; p < 0.05) was observed between caries increment and the frequency of daily intake of sugary snacks, soft drinks and tea with sugar at baseline only in Group 1. Conclusions: A quarterly application of MI varnish (CPP-ACP/fluoride) reduced caries increment in 6- and 12-year-old children in Riga, Latvia.

Effectiveness of Self-Assembling Peptide (P11-4) in Dental Hard Tissue Conditions: A Comprehensive Review

The limitations on the use of fluoride therapy in dental caries prevention has necessitated the development of newer preventive agents. This review focusses on the recent and significant studies on P11-4 peptide with an emphasis on different applications in dental hard tissue conditions. The self-assembling peptide P11-4 diffuses into the subsurface lesion assembles into aggregates throughout the lesion, supporting the nucleation of de novo hydroxyapatite nanocrystals, resulting in increased mineral density. P11-4 treated teeth shows more remarkable changes in the lesion area between the first and second weeks. The biomimetic remineralisation facilitated in conjunction with fluoride application is an effective and non-invasive treatment for early carious lesions. Despite, some studies have reported that the P11-4 group had the least amount of remineralised enamel microhardness and a significantly lower mean calcium/phosphate weight percentage ratio than the others. In addition, when compared to a low-viscosity resin, self-assembling peptides could neither inhibit nor mask the lesions significantly. Moreover, when it is combined with other agents, better results can be achieved, allowing more effective biomimetic remineralisation. Other applications discussed include treatment of dental erosion, tooth whitening and dentinal caries. However, the evidence on its true clinical potential in varied dental diseases still remains under-explored, which calls for future cohort studies on its in vivo efficacy.

Remineralization potential of P11-4 and fluoride on secondary carious primary enamel: A quantitative evaluation using microcomputed tomography

The aim of this study was to assess the ability of self-assembling peptide (P11-4) diffusion, assembly, and remineralization to effect artificial secondary caries-like lesions in human primary teeth in vitro. Enamel-dentin blocks obtained from extracted human primary molars were embedded into epoxy resin blocks. Cavities (approximately 1 × 1 × 2 mm) were prepared on the surface using a high-speed diamond bur under constant water cooling and filled with composite restorative material (Filtek Z250; 3 M ESPE). The samples were immersed in demineralizing solution (20 ml) for 96 h to produce secondary caries lesions and divided into two groups according to the testing materials: fluoride varnish (Duraphat; Colgate, UK) and P11-4 (Curodont Repair; Credentis, Switzerland). Except for the control areas, all samples were remineralized for 3-5 min using the remineralizing agents, and then all the sections were placed in a pH-cycling system for 5 days at 35°C. The pH cycling procedure was followed by micro-CT analysis for the qualitative evaluation of surface changes. The Mann-Whitney U test was used to compare two independent groups. In the comparison of more than two dependent groups, Bonferroni smoothed pairwise analyses were used to determine the source of the Kruskal-Wallis H test difference. The results of the study revealed that the remineralization depths of the peptide group were higher than those of the fluoride group (p < .01). There was a statistically significant difference in remineralization effects between the fluoride and peptide groups. P11-4 can be considered as an effective remineralizing agent for secondary caries lesions.

Exploring Parent's Satisfaction and the Effectiveness of Preformed Metal Crowns Fitting by Hall Technique for Carious Primary Molars in Jeddah Region, Saudi Arabia: Findings of a Prospective Cohort Study

PURPOSE

The Hall technique (HT) is a non-invasive approach to treating carious primary teeth. Its acceptability by parents and effectiveness is not widely known in the Middle East. Therefore, we aimed to conduct this study to explore the effectiveness of preformed metal crowns (PMCs) fitting by HT and to what extent the parent's satisfaction for their children in Jeddah region.

MATERIALS AND METHODS

A prospective cohort study was conducted in the outpatient pediatric dental clinic at Jeddah Specialty Dental Center, in 2018. The cohort of children was exposed to the HT and was recalled 3 months to two years later to examine present or absence of: crown loss, open margin, signs or symptoms of reversible or irreversible pulpitis, and if the tooth exfoliated naturally. Parents who agreed to undergo the HT for their children completed a 5-point Likert questionnaire after treatment and after three months.

RESULTS

A total of 48 children (72 teeth) were initially enrolled, but only 25 children (49 teeth) completed two years of follow-up. At 2 years follow-up, one PMC was lost (2.04%) while no teeth fitted with the HT required any further intervention. Around 96% of parents were satisfied with this procedure and 92% wanted other carious teeth to be treated similarly. All parents were satisfied with this technique because it did not include local anesthesia and no drilling. It was found that parents of girls were satisfied more than parents of boys and on average their satisfaction score at the time of treatment was 3.04 units higher than parents of boys with a significant p-value of 0.02 and 95% CI for the beta coefficient to be 0.46 to 5.62.

CONCLUSION

The HT is effective as a treatment of dental caries and it was generally accepted by parents initially and during their follow-up visits.

Advanced non-fluoride approaches to dental enamel remineralization: The next level in enamel repair management

In modern dentistry, a minimally invasive management of early caries lesions or early-stage erosive tooth wear (ETW) with synthetic remineralization systems has become indispensable. In addition to fluoride, which is still the non-plus-ultra in these early caries/ETW treatments, a number of new developments are in the test phase or have already been commercialized. Some of these systems claim that they are comparable or even superior to fluoride in terms of their ability to remineralize enamel. Besides, their use can help avoid some of the risks associated with fluoride and support treatments of patients with a high risk of caries. Two individual non-fluoride systems can be distinguished; intrinsic and extrinsic remineralization approaches. Intrinsic (protein/peptide) systems adsorb to hydroxyapatite crystals/organics located within enamel prisms and accumulate endogenous calcium and phosphate ions from saliva, which ultimately leads to the re-growth of enamel crystals. Extrinsic remineralization systems function on the basis of the external (non-saliva) supply of calcium and phosphate to the crystals to be re-grown. This article, following an introduction into enamel (re)mineralization and fluoride-assisted remineralization, discusses the requirements for non-fluoride remineralization systems, particularly their mechanisms and challenges, and summarizes the findings that underpin the most promising advances in enamel remineralization therapy.

Self-Assembling Peptides: From Design to Biomedical Applications

Self-assembling peptides could be considered a novel class of agents able to harvest an array of micro/nanostructures that are highly attractive in the biomedical field. By modifying their amino acid composition, it is possible to mime several biological functions; when assembled in micro/nanostructures, they can be used for a variety of purposes such as tissue regeneration and engineering or drug delivery to improve drug release and/or stability and to reduce side effects. Other significant advantages of self-assembled peptides involve their biocompatibility and their ability to efficiently target molecular recognition sites. Due to their intrinsic characteristics, self-assembled peptide micro/nanostructures are capable to load both hydrophobic and hydrophilic drugs, and they are suitable to achieve a triggered drug delivery at disease sites by inserting in their structure's stimuli-responsive moieties. The focus of this review was to summarize the most recent and significant studies on self-assembled peptides with an emphasis on their application in the biomedical field.

Recent advances in design and applications of biomimetic self-assembled peptide hydrogels for hard tissue regeneration

Abstract

The development of natural biomaterials applied for hard tissue repair and regeneration is of great importance, especially in societies with a large elderly population. Self-assembled peptide hydrogels are a new generation of biomaterials that provide excellent biocompatibility, tunable mechanical stability, injectability, trigger capability, lack of immunogenic reactions, and the ability to load cells and active pharmaceutical agents for tissue regeneration. Peptide-based hydrogels are ideal templates for the deposition of hydroxyapatite crystals, which can mimic the extracellular matrix. Thus, peptide-based hydrogels enhance hard tissue repair and regeneration compared to conventional methods. This review presents three major self-assembled peptide hydrogels with potential application for bone and dental tissue regeneration, including ionic self-complementary peptides, amphiphilic (surfactant-like) peptides, and triple-helix (collagen-like) peptides. Special attention is given to the main bioactive peptides, the role and importance of self-assembled peptide hydrogels, and a brief overview on molecular simulation of self-assembled peptide hydrogels applied for bone and dental tissue engineering and regeneration.

Graphic abstract

Clinical Use of the Self-Assembling Peptide RADA16: A Review of Current and Future Trends in Biomedicine

RADA16 is a synthetic peptide that exists as a viscous solution in an acidic formulation. In an acidic aqueous environment, the peptides spontaneously self-assemble into β-sheet nanofibers. Upon exposure and buffering of RADA16 solution to the physiological pH of biological fluids such as blood, interstitial fluid and lymph, the nanofibers begin physically crosslinking within seconds into a stable interwoven transparent hydrogel 3-D matrix. The RADA16 nanofiber hydrogel structure closely resembles the 3-dimensional architecture of native extracellular matrices. These properties make RADA16 formulations ideal topical hemostatic agents for controlling bleeding during surgery and to prevent post-operative rebleeding. A commercial RADA16 formulation is currently used for hemostasis in cardiovascular, gastrointestinal, and otorhinolaryngological surgical procedures, and studies are underway to investigate its use in wound healing and adhesion reduction. Straightforward application of viscous RADA16 into areas that are not easily accessible circumvents technical challenges in difficult-to-reach bleeding sites. The transparent hydrogel allows clear visualization of the surgical field and facilitates suture line assessment and revision. The shear-thinning and thixotropic properties of RADA16 allow its easy application through a narrow nozzle such as an endoscopic catheter. RADA16 hydrogels can fill tissue voids and do not swell so can be safely used in close proximity to pressure-sensitive tissues and in enclosed non-expandable regions. By definition, the synthetic peptide avoids potential microbiological contamination and immune responses that may occur with animal-, plant-, or mineral-derived topical hemostats. In vitro experiments, animal studies, and recent clinical experiences suggest that RADA16 nanofibrous hydrogels can act as surrogate extracellular matrices that support cellular behavior and interactions essential for wound healing and for tissue regenerative applications. In the future, the unique nature of RADA16 may also allow us to use it as a depot for precisely regulated drug and biopharmaceutical delivery.

Self-assembling peptide P11-4 in remineralization of enamel caries - a systematic review of in-vitro studies

OBJECTIVE

The present systematic review was conducted to investigate the effect of the self-assembling peptide (SAP) - P₁₁-4 in the remineralization of enamel caries.

MATERIAL AND METHODS

The systematic search for studies was conducted through CINAHL, EMBASE, MEDLINE, Scopus, PsychINFO, and various key journals. This review was conducted in adherence to PRISMA standards and was registered in PROSPERO with registration number CRD42019110156. The methodological quality of the studies was graded through Cochrane's tool of risk of bias in non-randomized studies - of interventions (ROBINS-I).

RESULTS

In total, 91 studies were identified for screening, and 12 studies were eligible. Ten studies showed effective enamel remineralization with P₁₁-4 compared to controls. One study showed a combination of P₁₁-4 with fluoride varnish or Casein Phosphopeptide-Amorphous Calcium Phosphate Fluoride (CPP-ACPF) leads to significantly higher remineralization compared to P₁₁-4 alone. Quality assessment of study showed 6 (50%) studies as medium risk of bias and 6 (50%) studies as low risk of bias.

CONCLUSION

To conclude, the present study results showed SAP- P₁₁-4 is effective in the remineralization of enamel caries.

Building an aprismatic enamel-like layer on a demineralized enamel surface by using carboxymethyl chitosan and lysozyme-encapsulated amorphous calcium phosphate nanogels

OBJECTIVES

The purpose of this study was to prepare carboxymethyl chitosan (CMC) and lysozyme nanogels that could encapsulate amorphous calcium phosphate (ACP) for achieving its controlled delivery, thus forming an aprismatic enamel-like layer on the demineralized enamel surface.

METHODS

CMC/LYZ-ACP nanogels were developed, and the controlled delivery of ACP from the nanogels was induced by the presence of NaCl. The nanogel morphologies at various NaCl concentrations was measured by transmission electron microscopy (TEM). The particle sizes and zeta potentials (ζ-potential) of the samples were determined using a combined dynamic light scattering/particle electrophoresis instrument. Comparing the remineralization effect of the CMC/LYZ-ACP nanogels on the demineralized enamel surface with that of a fluoride treatment, the remineralization effect was examined by nanoindentation tests, X-ray diffraction (XRD), confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM).

RESULTS

CMC/LYZ-ACP nanogels were negatively charged spherical structures with a particle size of approximately 300 nm. At high concentrations of NaCl (0.15 M), ACP was dissociated from the disassembled nanogels and transformed into hydroxyapatite (HAP). Groups treated with the CMC/LYZ-ACP nanogels showed the regeneration of an aprismatic enamel-like layer on an acid-etched enamel surface, which provided increased mechanical properties (P < 0.05) and a high impermeability (P < 0.01) compared to those of the fluoride-treated group.

CONCLUSIONS

This research provides a new idea for the stable and controllable delivery of ACP from CMC/LYZ-ACP nanogels, which can form an aprismatic enamel-like layer in situ on the surface of demineralized enamel. In regard to further clinical development, this material and method may be promising for treating early enamel caries.

Comparative evaluation of fluoride varnishes, self-assembling peptide-based remineralization agent, and enamel matrix protein derivative on artificial enamel remineralization in vitro

Background

One of the most unfavorable side effects of fixed orthodontic treatment is white spot lesions (WSLs). Although the most important approach is prevention of WSLs, it is also essential to evaluate the efficacy of the remineralization agents. However, there is no concurrence in the literature with respect to the remineralization process of these agents. The objective of the present study was to evaluate the effects of different fluoride varnishes, enamel matrix protein, and self-assembling peptide derivatives with varying chemical compositions on remineralization of artificially created WSLs in vitro using quantitative light-induced fluorescence (QLF).

Methods

Artificial WSLs were created on bovine enamel samples using acidic buffer solution (pH 5, 10 days). Specimens were randomly allocated to six groups (n = 10/group): (1) Emdogain (Straumann, Basel, Switzerland), (2) Curodont Repair (Credentis AG, Switzerland), (3) Duraphat (Colgate-Palmolive, New York, NY), (4) Clinpro XT (3 M ESPE, Pymble, New South Wales, Australia), (5) Enamel Pro Varnish (Premier Dental Products, PA, USA), and (6) control (untreated). The agents were applied to the WSLs according to the manufacturers’ instructions. Fluorescence loss (ΔF), lesion area (area), and impact (ΔQ) values of enamel surfaces were quantified by QLF-D Biluminator^TM (Inspektor-Pro, Amsterdam, The Netherlands) at baseline and after 7, 14, and 21 days of application of the respective materials.

Results

ΔF value presented a significantly decreasing trend throughout the 21 days for all groups except the Duraphat and Enamel Pro varnishes. The changes between 14th and 21st days of the Clinpro XT varnish application were significantly higher than Emdogain, Curodont, and Enamel Pro. The Curodont group showed higher lesion area changes between the first and second week in comparison to the Emdogain, Clinpro XT, and Enamel Pro groups, whereas Clinpro XT assured the highest reduction from the second to the third week of the observation period.

Conclusions

The fluorescence loss was significantly reduced with enamel matrix protein, self-assembling peptide, and light-curable fluoride varnishes in the analysis for 21 days. Curodont and Clinpro XT were effective in diminishing the fluorescence loss and lesion area compared to the Duraphat, Enamel Pro fluoride varnishes, and Emdogain in different time points.

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.

When to intervene in the caries process? A Delphi consensus statement

Objectives To define an expert Delphi consensus on when to intervene in the caries process and existing carious lesions.Methods Non-systematic literature synthesis, expert Delphi consensus process and expert panel conference.Results Lesion activity, cavitation and cleansability determine intervention thresholds. Inactive lesions do not require treatment (in some cases, restorations may be placed for form, function, aesthetics); active lesions do. Non-cavitated carious lesions should be managed non- or micro-invasively, as should most cavitated lesions which are cleansable. Cavitated lesions which are not cleansable usually require minimally invasive management. In specific circumstances, mixed interventions may be applicable. Occlusally, cavitated lesions confined to enamel/non-cavitated lesions extending radiographically into deep dentine may be exceptions. Proximally, cavitation is hard to assess tactile-visually. Most lesions extending radiographically into the middle/inner third of dentine are assumed to be cavitated. Those restricted to the enamel are not cavitated. For lesions extending radiographically into the outer third of dentine, cavitation is unlikely. These lesions should be managed as if they were non-cavitated unless otherwise indicated. Individual decisions should consider factors modifying these thresholds.Conclusions Comprehensive diagnosis is the basis for systematic decision-making on when to intervene in the caries process and existing lesions.

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.

A Century of Change towards Prevention and Minimal Intervention in Cariology

Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.

Development and application of a 3D periodontal in vitro model for the evaluation of fibrillar biomaterials

Background

Periodontitis is a chronic inflammation of the tooth supporting structures that finally can lead to tooth loss. As chronic periodontitis is associated with systemic diseases multiple approaches have been followed to support regeneration of the destructed tissue. But very few materials are actually used in the clinic. A new and promising group of biomaterials with advantageous biomechanical properties that have the ability to support periodontal regeneration are self-assembling peptides (SAP). However, there is still a lack of 3D periodontal models that can evaluate the migration potential of such novel materials.

Methods

All experiments were performed with primary human periodontal ligament fibroblasts (HPLF). Migration capacity was assessed in a three-dimensional model of the human periodontal ligament by measuring the migration distance of viable cells on coated (Enamel Matrix Protein (EMP), P11–4, collagen I) or uncoated human dentin. Cellular metabolic activity on P11–4 hydrogels was assessed by a metabolic activity assay. Deposition of ECM molecules in a P11–4 hydrogel was visualized by immunostaining of collagen I and III and fibrillin I.

Results

The 3D periodontal model was feasible to show the positive effect of EMP for periodontal regeneration. Subsequently, self-assembling peptide P11–4 was used to evaluate its capacity to support regenerative processes in the 3D periodontal model. HPLF coverage of the dentin surface coated with P11–4 increased significantly over time, even though delayed compared to EMP. Cell viability increased and inclusion of ECM proteins into the biomaterial was shown.

Conclusion

The presented results indicate that the 3D periodontal model is feasible to assess periodontal defect coverage and that P11–4 serves as an efficient supporter of regenerative processes in the periodontal ligament.

Clinical relevance

The establishment of building-block synthetic polymers offers new opportunities for clinical application in dentistry. Self-assembling peptides represent a new generation of biomaterials as they are able to respond dynamically to the changing environment of the biological surrounding. Especially in the context of peri-implant disease prevention and treatment they enable the implementation of new concepts.

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.

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.

Comparing the efficacy of hydroxyapatite nucleation regulated by amino acids, poly-amino acids and an amelogenin-derived peptide

The efficacy of HAP nucleation regulated by amino acids, poly-amino acids and an amelogenin-derived peptide named QP5 was compared systematically. Poly-amino acids and QP5 regulated HAP nucleation and enamel remineralization more effectively.

When to intervene in the caries process? An expert Delphi consensus statement

OBJECTIVES

To define an expert Delphi consensus on when to intervene in the caries process and on existing carious lesions using non- or micro-invasive, invasive/restorative or mixed interventions.

METHODS

Non-systematic literature synthesis, expert Delphi consensus process and expert panel conference.

RESULTS

Carious lesion activity, cavitation and cleansability determine intervention thresholds. Inactive lesions do not require treatment (in some cases, restorations will be placed for reasons of form, function and aesthetics); active lesions do. Non-cavitated carious lesions should be managed non- or micro-invasively, as should most cavitated carious lesions which are cleansable. Cavitated lesions which are not cleansable usually require invasive/restorative management, to restore form, function and aesthetics. In specific circumstances, mixed interventions may be applicable. On occlusal surfaces, cavitated lesions confined to enamel and non-cavitated lesions radiographically extending deep into dentine (middle or inner dentine third, D2/3) may be exceptions to that rule. On proximal surfaces, cavitation is hard to assess visually or by using tactile methods. Hence, radiographic lesion depth is used to determine the likelihood of cavitation. Most lesions radiographically extending into the middle or inner third of the dentine (D2/3) can be assumed to be cavitated, while those restricted to the enamel (E1/2) are not cavitated. For lesions radiographically extending into the outer third of the dentine (D1), cavitation is unlikely, and these lesions should be managed as if they were non-cavitated unless otherwise indicated. Individual decisions should consider factors modifying these thresholds.

CONCLUSIONS

Comprehensive diagnostics are the basis for systematic decision-making on when to intervene in the caries process and on existing carious lesions.

CLINICAL RELEVANCE

Carious lesion activity, cavitation and cleansability determine intervention thresholds. Invasive treatments should be applied restrictively and with these factors in mind.

Self-assembling peptides cross-linked with genipin: resilient hydrogels and self-standing electrospun scaffolds for tissue engineering applications

Self-assembling peptides (SAPs) are synthetic bioinspired biomaterials that can be feasibly multi-functionalized for applications in surgery, drug delivery, optics and tissue engineering (TE). Despite their promising biocompatibility and biomimetic properties, they have never been considered real competitors of polymers and/or cross-linked extracellular matrix (ECM) natural proteins. Indeed, synthetic SAP-made hydrogels usually feature modest mechanical properties, limiting their potential applications, due to the transient non-covalent interactions involved in the self-assembling phenomenon. Cross-linked SAP-hydrogels have been recently introduced to bridge this gap, but several questions remain open. New strategies leading to stiffer gels of SAPs may allow for a full exploitation of the SAP technology in TE and beyond. We have developed and characterized a genipin cross-linking strategy significantly increasing the stiffness and resiliency of FAQ(LDLK)3, a functionalized SAP already used for nervous cell cultures. We characterized different protocols of cross-linking, analyzing their dose and time-dependent efficiency, influencing stiffness, bioabsorption time and molecular arrangements. We choose the best developed protocol to electrospin into nanofibers, for the first time, self-standing, water-stable and flexible fibrous mats and micro-channels entirely made of SAPs. This work may open the door to the development and tailoring of bioprostheses entirely made of SAPs for different TE applications.

Peptide Self-Assembly into Hydrogels for Biomedical Applications Related to Hydroxyapatite

Amphiphilic peptides can be self-assembled by establishing physical cross-links involving hydrogen bonds and electrostatic interactions with divalent ions. The derived hydrogels have promising properties due to their biocompatibility, reversibility, trigger capability, and tunability. Peptide hydrogels can mimic the extracellular matrix and favor the growth of hydroxyapatite (HAp) as well as its encapsulation. Newly designed materials offer great perspectives for applications in the regeneration of hard tissues such as bones, teeth, and cartilage. Furthermore, development of drug delivery systems based on HAp and peptide self-assembly is attracting attention.

Randomised in situ clinical trial investigating self-assembling peptide matrix P11-4 in the prevention of artificial caries lesions

The aim was to investigate the ability of self-assembling Peptide P11-4 Matrix (SAPM) to remineralize artificial initial caries lesions compared to the use of fluoride varnish. Volunteers were recruited for this randomised, cross-over in situ trial. Bovine specimens, half including orthodontic brackets, were recessed on the buccal aspects of mandibular appliances. Specimens included internal sound enamel control, a demineralised control and a part exposed during the in situ phase. Each phase lasted four weeks, followed by a one-week washout. Treatment groups were: A: negative control, no treatment,B: positive control, 22,600 ppm fluoride varnish,C: test group, 1,000 ppm SAPM. Laser fluorescence values (LF) were measured before/after demineralisation, and after the in situ period. Micro-CT analysis was used to assess mineral changes within the specimens after the in situ phase. In specimens without brackets, ΔLF values after in situ phase were: A: +5.28, B: +0.85, C: −2.89. Corresponding ΔLF for specimens with brackets were: A: +5.77, B: +1.30, C: −3.15. LF-values between groups significantly differed from each other (p < 0.0001) after the in situ phase. Micro-CT analysis yielded no significant difference among groups for specimens without brackets. For specimens with brackets, the test group showed significantly more remineralisation than the negative (p = 0.01) and positive control (p = 0.003). Within the limitations of the study, SAPM showed prevention of caries and remineralisation of enamel around orthodontic brackets.

Enamel biomimetics-fiction or future of dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

Enamel biomimetics-fiction or future of dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

Five pathways for tooth enamel engineering hold great promise for developing new technologies, leading to novel biomaterials and biotechnologies to regenerate enamel tissue. Tooth enamel is a unique tissue-specific biomaterial with exceptional structural and mechanical properties. In recent years, many approaches have been adopted to generate or regenerate this complex tissue; Mirali Pandya and Thomas Diekwisch of Texas A&M College of Dentistry, USA conducted a review of the current state and future directions of enamel tissue engineering. In their review, the authors focused on five pathways for enamel tissue engineering: (1) physical synthesis of enamel; (2) biochemical enamel engineering; (3) in situ enamel engineering; (4) cell-based enamel engineering; and (5) whole tooth regeneration. The authors conclude that those five approaches will help identify the biological mechanisms that lead to the generation of tooth enamel.