This study evaluated the effects of fluoride on subsurface enamel demineralization induced by two commonly used chemical models. Forty-eight enamel blocks were demineralized at pH = 5.0 by an acetate buffer (Group 1), a lactate buffer (Group 2), an acetate buffer with 0.02 ppm fluoride (Group 3) and a lactate buffer with 0.02 ppm fluoride (Group 4) at 25 °C for 3 weeks. The surface destruction percentage (SDP), mineral loss and lesion depth of the blocks were studied using micro-computed tomography. An elemental analysis of the enamel surface was evaluated using an energy-dispersive X-ray spectroscopy. Surface micro-hardness was determined by the Knoop Hardness Test. The mean lesion depth of Groups 1 through 4 were 134.1 ± 27.2 µm, 96.1 ± 16.5 µm, 97.5 ± 22.4 µm and 91.1 ± 16.2 µm, respectively (p < 0.05; group 1 > 2, 3 > 4). The SDPs of groups 1 through 4 were 7.8 ± 8.93%, 0.71 ± 1.6%, 0.36 ± 1.70% and 1.36 ± 2.94% (p < 0.01; group 1 > 2, 3, 4). The fluoride in mean weight percentages of groups 1 through 4 were 1.12 ± 0.24%, 1.10 ± 0.20%, 1.45 ± 0.40% and 1.51 ± 0.51%, respectively (p < 0.01; group 3,4 > 1,2). The mean Knoop hardness values of groups 1 through 4 were 27.5 ± 13.3, 39.7 ± 19.3, 73.6 ± 44.2 and 91.0 ± 57.2, respectively (p < 0.01; group 4 > 3 > 2 > 1). The chemical model using an acetate buffer solution created significantly deeper zones of subsurface demineralization on enamel than the lactate buffer solution. An acetate buffer may damage the enamel surface, but the surface damage can be prevented by adding fluoride.

ADAM10 is a multi-functional proteinase that can cleave approximately 100 different substrates. Previously, we demonstrated that ADAM10 is expressed by ameloblasts responsible for enamel formation. Here we asked if ADAM10 plays a role in enamel development. Deletion of Adam10 in mice is embryonic lethal and deletion of Adam10 from epithelia is perinatal lethal. We therefore deleted Adam10 from ameloblasts. Here, we confirm ameloblast-specific expression of the Tg(Amelx-iCre)872pap construct. We crossed these mice with Adam10 floxed mice to generate Amelx-iCre; Adam10fl/fl mice (Adam10 cKO). We show that Adam10 cKO mice have discolored teeth with softer than normal enamel. Notably, the Adam10 cKO enamel density and volume were significantly reduced in both incisors and molars. Moreover, the incisor enamel rod pattern became progressively more disorganized moving from the DEJ to the outer enamel surface and this disorganized rod structure created large gaps between and among the rods. ADAM10 cleaves proteins essential for cell signaling and for enamel formation such as RELT and COL17A1. ADAM10 also cleaves cell-cell contacts such as E- and N-cadherins that may support ameloblast movement necessary for normal rod patterns. Here, we show for the first time that ADAM10 expressed by ameloblasts is essential for proper enamel formation.

Objectives: The hierarchical structure of enamel gives insight on the properties of enamel and can influence its strength and ultimately caries experience. Presently, past caries experience is quantified using the decayed, missing, filled teeth/decayed, missing, filled surface (DMFT/DMFS for permanent teeth; dmft/dmfs for primary teeth) or international caries detection and assessment system (ICDAS) scores. By analyzing the structure of enamel, a new measurement can be utilized clinically to predict susceptibility to future caries experience based on a patient’s individual’s biomarkers. The purpose of this study was to test the hypothesis that number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas, influence caries experience through genetic variation of the genes involved in enamel formation. Materials and Methods: Scanning electron microscopy (SEM) images of enamel from primary teeth were used to measure number of prisms by square millimeter and interprismatic spaces, prism density and gap distances between prisms in the enamel samples. The measurements were tested to explore a genetic association with variants of selected genes and correlations with caries experience based on the individual’s DMFT+ dmft score and enamel microhardness at baseline, after an artificial lesion was created and after the artificial lesion was treated with fluoride. Results: Associations were found between variants of genes including ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, beta defensin 1, matrix metallopeptidase 20 and enamel structure variables measured. Significant correlations were found between caries experience and microhardness and enamel structure. Negative correlations were found between number of prisms by square millimeter and high caries experience (r value= -0.71), gap distance between prisms and the enamel microhardness after an artificial lesion was created (r value= -0.70), and gap distance between prisms and the enamel microhardness after an artificial lesion was created and then treated with fluoride (r value= -0.81). There was a positive correlation between number of prisms by square millimeter and prism density of the enamel (r value= 0.82). Conclusions: our data support that genetic variation may impact enamel formation, and therefore influence susceptibility to dental decay and future caries experience. Clinical Relevance: The evaluation of enamel structure that may impact caries experience allows for hypothesizing that the identification of individuals at higher risk for dental caries and implementation of personalized preventative treatments may one day become a reality.

The aim was to evaluate the effect of different whitening toothpastes on the enamel surface roughness and color variation. Twenty-four molars were sectioned and divided into eight groups (n = 3), considering the two factors under study: toothpaste type (Colgate® Total Original, Oral B® 3D White Luxe Perfection, Curaprox® Black is White, and Signal® White Now) and brushing protocol (short-term and a long-term). Surface roughness was examined by atomic force microscopy (AFM), and color change (ΔE) was measured using the CIE L*a*b* system. Data were statistically analyzed using comparative parametric tests at a 5% significance level. In the short-term protocol, only the Signal® White Now toothpaste increased surface roughness (p = 0.038) compared to the Colgate® Total Original group. No significant differences (p > 0.05) were observed in surface roughness in the long-term protocol. Regarding color variation, no statistically significant differences (p > 0.05) were observed in either protocol. Overall, the whitening toothpastes did not affect enamel surface roughness or color, except for Signal® White Now causing increased roughness in the short-term protocol. However, all toothpastes induced a visual change in color.

Aim: The purpose of this study was to collect prevalence data of Hypomineralized Second Primary Molars (HSPM) and Molar Incisor Hypomineralization (MIH) among pediatric patients treated by dental practitioners in Northern Italy and assess the practitioners’ awareness of these conditions. Methods: A cross-sectional pilot study was conducted using a structured online questionnaire administered through Google Forms. The survey comprised 10 single-choice questions addressing the prevalence of opacities affecting molars and an index of HSPM and MIH in caries-free children aged 6-9 years, categorized by percentage. Results: A total of 315 dentists participated in the survey, yielding a response rate of 31.5%. The majority of respondents (59%) reported HSPM prevalence in 1-25% of their patients, while 18% observed no opacity in any of their patients. MIH was observed in HSPM patients in 1-25% and 25-50% of cases, as reported by 44% and 31% of respondents, respectively. Among non-HSPM patients, MIH was observed in 1-25% of children (reported by 74% of respondents). Conclusion: The findings from this pilot survey show substantial agreement with existing prevalence data on HSPM and MIH reported in the literature. The co-occurrence rate of HSPM and MIH defects supports the hypothesis of HSPM potentially serving as a predictor of MIH. The study underscores a significant need to enhance awareness of these defects for early diagnosis and effective management. Additionally, there is a call for the promotion of standardized diagnostic protocols to obtain more accurate epidemiological data.

Background: We investigated the effect of bioactive glass and zinc oxide nanoparticles on enamel remineralization, as well as their antibacterial effect on cariogenic bacteria. Methods: Fluoride gel (F), bioactive glass microparticles (µB), bioactive glass nanoparticles (nB), zinc oxide nanoparticles (Z), and a mixed suspension of nB and Z (nBZ) were prepared and subjected to the following tests: morphological evaluation by scanning and transmission electron microscopy, measurement of specific surface area, zeta potential measurement, crystal structure analysis by X-ray diffraction, and acid buffering capacity test. Further, we performed a remineralization cycle test of 28 days and a nanoindentation testing was carried out during the immersion period and then the enamel surfaces were examined using scanning electron microscopy. Additionally, the antibacterial effects of the sample suspensions were evaluated by measuring their minimum bactericidal concentrations against various cariogenic bacteria. Results: Our results revealed that nB had a near-circular shape with an amorphous structure, a considerably large specific surface area due to nanoparticulation. Additionally, nB possessed a rapid acid buffering capacity, which was comparable to that of μB. In the remineralization test, faster recovery of mechanical properties was observed on the enamel surface immersed in samples containing bioactive glass nanoparticles (nB and nBZ). After remineralization, demineralized enamel immersed in any of the samples showed a rough and porous surface structure covered with mineralized structures. Furthermore, nBZ exhibited a broad antibacterial spectrum. Conclusions: These results demonstrated that bioactive glass and zinc oxide nanoparticles have superior demineralization-suppressing and remineralization-promoting effects.

Objectives: This study aimed to develop novel self-adhesive resins for orthodontic bracket bonding that can provide clinically acceptable bond strengths, leave minimal remnant adhesive and enamel damage upon bracket debonding. Materials and Methods: A plain self-adhesive resin was used as a control, from which three main modified self-adhesive resin groups were developed for bracket bonding: bioactive glass, strontium fluoride and grape seed extract. All groups were subjected to three artificial aging models prior to shear bond strength, adhesive remnant index, enamel damage index and micro-hardness assessments. Results: All groups yielded clinically acceptable shear bond strength values. The addition of 0.5% grape seed extract to plain self-adhesive resin+1% bioactive glass yielded the highest shear bond strength, minimal adhesive remnant index and minimal enamel damage post debonding, yet the differences were statistically insignificant (p>0.05). The best performance regarding microhardness was displayed by the addition of 0.5% grape seed extract. Conclusions: The formulation (1% bioactive glass+ 0.5% grape seed extract) yielded clinically satisfactory shear bond strength, minimal adhesive residue, minimal enamel damage, and highest micro-hardness mean value as compared to the control and other experimental self-adhesive resin groups.

This Systematic Review examines studies focusing on tooth bleaching and its effect on healthy enamel or incipient caries and bacterial adhesion. The aim is to explore the impact of different bleaching agents on incipient caries lesions and healthy enamel. Randomized controlled trials, clinical trials, observational studies, and in vitro studies that compared at least two groups were included. A comprehensive search strategy was used to select studies from Pubmed and Scopus databases. Two evaluators performed data extraction, screening, and quality assessment independently. Only studies written in English were included. From 968 initial records, 28 studies were selected for a full-text evaluation. 7 studies were classified as cluster 1 (bacterial adherence on teeth), 12 studies as cluster 2 (no bacteria involved), 4 studies as cluster 3 (no teeth deployment), and 5 clinical studies were cluster 4. Of the selected studies, 6 (21.43%) supported increased bacterial attachment capacity and cariogenic dynamics, 4 (14.29%) decreased adhesion and cariogenic activity, 7 (25%) no difference, and 11 (39.28%) followed a differentiated methodological approach and could not be categorized. Due to different methodology strategies used in the studies of all clusters, the risk of bias was high. Thus, we cannot reach a confident conclusion.

Enamel erosion is a process which happens every time we eat and it may be accelerated by some particular acid foods, drinks or other agents. Dental enamel when damaged by low pH substances becomes chalky, rough, opaque, yellowed and it can be related to dentinal hypersensitivity. To the present day, several possible solutions are available, therefore the aim of this study was to evaluate the effect of a biocompatible minerals serum based on calcium silicate, sodium phosphate and fluoride (Regenerate™) on the damaged enamel by four different acid liquids. 135 ovine teeth were equally divided into 5 groups and submerged for one week into lemon juice, energy drink, coffee, tea and physiologic solution for the negative control. The first 4 groups were evaluated for their color with an analogical color scale (Vita® Scale) and for their surface assigning a qualitative aspect among opaque, rough, chalky or smooth. Then they were treated with hydroxyapatite gels and re-evaluated for the same parameters. Data were checked for the normal distribution with Shapiro-Wilk test and analyzed with dependent t-test or Wilcoxon Signed Rank test, every test with a p≤0.05. Both color and surface aspect showed a strongly significant improvement after the treatment. Biocompatible minerals serum based on hydroxyapatite is able to reverse teeth erosion, improve the color and restore the smoothness of the dental enamel.

Detecting cracks in teeth is a clinical challenge. Patients may complain of diffuse pain on chewing, pain, at times, on temperature change and pain that occurs episodically. Common diagnostic tools such as radiographs and visual examination may not detect cracks. This case report shows how PTR-LUM in The Canary System can detect cracks in teeth not seen with other devices. In this clinical situation, the crack involved a portion of the mesial and distal surfaces of a mandibular second molar.

The aim of this study was to synthetize a hydroxyapatite-capsaicin composite (HAp-CAP) and to evaluate its physicochemical data for further use in hydrogen peroxide in-office dental bleaching gel. The HAp-CAP was prepared by the precipitation method, performed in a 4:1 ratio using 3.2 g of nano-hydroxyapatite (nano-HAp) and 0.8 g of capsaicin (CAP) in 99.5% ethyl alcohol (q.s.p) and zirconia beads at SpeedMixer®. The HAp-CAP was characterized by morphological, spectroscopic, and thermal analyses. In the following, the HAp-CAP was added to an in-office dental bleaching to test its effect on reducing hydrogen peroxide diffusion into the pulp chamber, as well as the effect in the color alteration during dental bleaching. The HAp-CAP were suitably obtained by the precipitation method, and the results demonstrates that the thermal stability of the CAP is greatly improved after reaction of HAp and CAP. The HAp-CAP into a bleaching gel slightly decreased the amount of hydrogen peroxide inside the pulp chamber and didn’t interfering in the bleaching effectiveness of dental bleaching. The HAp-CAP synthesis and characterization were successfully carried out, and its use in dental materials is a challenging task that needs further study since its addition.

This study was aimed at investigating the protective effects of glass ionomer cement (GIC) and surface pre-reacted glass ionomer (S-PRG) fillers used as dental restorative materials on demineralization of bovine enamel. GlasIonomer FX ULTRA (FXU), Fuji IX GP Extra (FIXE), CAREDYNE RESTORE (CDR) were used as GICs. PRG Barrier Coat (BC) was used as the S-PRG filler. They were incubated in a lactic acid solution (pH = 4.0) for 6 d at a temperature of 37 °C. The mineral was etched from the enamel surface, and a large number of Ca and P ions were detected in solution. The Al, F, Na, Sr, and Sr ions were released in GICs and S-RPG fillers. The Zn ion was released only in CDR and the B ion was released only in BC. The presence of apparent enamel prism peripheries was observed after 6 d of treatment for the group containing only enamel blocks. pH values for the FXU, FIXE, CDR, BC, and enamel block groups after 6 d were 6.5, 6.6, 6.7, 5.9, and 5.1, respectively. Therefore, the observed pH neutralization effect suppressed progression of caries due to the release of several ions from the restoratives.

The aim of this article is to evaluate and compare, retrospectively, the efficacy of two regenerative periodontal procedures in patients suffering from aggressive periodontitis (AgP). Twenty-eight patients were diagnosed with AgP, suffering from multiple intra-bony defects (IBD); that were treated by one of two regenerative modalities of periodontal therapy randomly assigned to each patient: a. guided tissue regeneration (GTR) or b. an application of enamel matrix derivatives (EMD) combined with DBX. The monitoring of the treated sites included recordings of probing depth (PD), clinical attachment level (CAL), and gingival recession. Pre-treatment and follow-up (up to 10 years from the surgery) recordings were analyzed statistically within and between groups. A significant reduction was shown at time on PD and CAL values, however, not between subject groups. CAL values decreased in all sites. At EMD group (44 sites) CAL gain was 1.92 mm (±1.68) from pre-treatment to follow-up (p<0.001) and at the GTR group (12 sites) CAL gain of 2.27 (±1.82) mm. In conclusion, 1-10 years observations have shown that surgical treatment of AgP patients by either GTR or by application of EMD/DBX results in similar successful clinical results.

The aim of this randomized controlled clinical trial was to compare the 2-year clinical performance of resin composite restorations placed at non-caries cervical lesions (NCCL) with one-step self-etch, total-etch, and selective enamel etch & self-etch adhesive techniques. Thirty-two patients received three resin composite restorations each at NCCLs (Tetric EvoCeram/Ivoclar/Vivadent), bonded with a total-etch adhesive agent (ExciTE F/Ivoclar/Vivadent) and a self-etch (AdheSE One F/Ivoclar/Vivadent) without and with selective enamel etching. All restorations were evaluated by two examiners at baseline, 6-, 12-, 18- and 24-months post-operation regarding retention, caries occurrence, marginal adaptation, and marginal staining. A logistic regression analysis with generalized estimating equations was used. After 2 years, the retention rate was 86,8% for total-etch, 92.26% for self-etch, and 93.63% for selective enamel etching & self-etch. No caries were detected during all the restorations. Concerning marginal adaptation, the clinically perfect restorations were 26.9% for the total-etch technique, 16% for self-etch, and 25,9% for selective enamel etch & self-etch. All three adhesive strategies provided restorations with no significant differences in the retention rate and the marginal adaptation, whereas the total etch yielded better performance for marginal staining. All the restorations were assessed as clinically acceptable after 2 years.

Here we report the preparation and characterization of a novel biomimetic toothpaste containing morphogenetically active amorphous polyphosphate (polyP) microparticles enriched with retinyl acetate (“a-polyP/RA-MP”). The spherical microparticles (average size, 550±120 nm), prepared by co-precipitating sodium-polyP with calcium chloride and supplemented with retinyl acetate, were incorporated into a basis toothpaste at a final concentration of 1% or 10%. The paste containing “a-polyP/RA-MP” significantly increased the growth of human mesenchymal stem cells (MSC), compared to a commercial toothpaste which acts rather inhibitory and the paste without polyP and retinyl acetate. qRT-PCR experiments revealed that the retinoid causes an induction of the expression of the MSC marker genes for osteoblast differentiation encoding collagen type I and alkaline phosphatase. On the other hand, the polyP ingredient, supplied as Zn-polyP microparticles (“Zn-a-polyP-MP”) strongly inhibited the growth of the cariogenic bacterium Streptococcus mutans. We demonstrate that the amorphous polyP-containing toothpaste, enriched with retinyl acetate, efficiently repairs both cracks/fissures and carious lesions in the tooth enamel, and reseals dentinal tubules, already after a 5 d treatment (brushing) of teeth twice daily for 5 min as examined by SEM and quantitative EDX analysis. The stability of the occlusion of dentin cracks even turned out to resist against short high power sonication treatment. Our results demonstrate that the novel toothpaste prepared here, containing amorphous polyP and retinyl acetate, is particularly suitable for prevention/repair of (cariogenic) damages of tooth enamel/dentin and for treatment of dental hypersensitivity.

Aim: The purpose of this study is to evaluate the remineralization potential of primary teeth enamel after being exposed to different laser diode therapy. Methods: Ninety-six vestibular primary teeth enamel samples were divided into eight groups (n=12) with varying treatments: control (G1), CPP-ACP-fluoride varnish (G2), diode lasers at 980 nm (G3), 808 nm (G4), 450 nm (G5), 980 nm + CPP-ACP-fluoride varnish (G6), 808 nm + CPP-ACP-fluoride varnish (G7), and 450 nm + CPP-ACP-fluoride varnish (G8). Each sample was assessed using DIAGNOdent® at baseline, post-treatment, and post-pH cycle re-mineralization. SEM imaging was performed before and after treatment and following the pH cycle. Results: The results indicated that the 980 nm and 808 nm diode lasers, both alone and in combination with CPP-ACP-fluoride varnish, either maintained or increased the calcium (Ca) weight percentage (Wt%) in the enamel. The 980 nm diode laser combined with CPP-ACP-fluoride varnish (G6) showed a significant increase in Ca Wt%, suggesting a strong remineralization effect. Similarly, the 808 nm diode laser alone (G4) also promoted a substantial increase in Ca Wt%. In contrast, the 450 nm diode laser, whether applied alone or in combination with CPP-ACP-fluoride varnish, resulted in a lower Ca Wt% and an increase in phosphorus (P) Wt%. Most groups, except for the CPP-ACP-fluoride varnish alone (G2), demonstrated an increase in P Wt%, indicating a complex interaction between laser therapy and enamel remineralization. Conclusions: The combined use of laser therapy with CPP-ACP-fluoride varnish significantly enhanced the remineralization of temporary teeth enamel. The 980 nm diode laser + CPP-ACP-fluoride varnish showed the most pronounced improvement in remineralization, while the 808 nm diode laser alone also effectively increased calcium solubility. These findings suggest that higher wavelength diode lasers, particularly when combined with remineralizing agents, can effectively enhance the mineral content of primary teeth and promote enamel remineralization.