Dental caries is a highly prevalent diet-related disease and is a major public health problem. A goal of modern dentistry is to manage non-cavitated caries lesions non-invasively through ...remineralization in an attempt to prevent disease progression and improve aesthetics, strength, and function. Remineralization is defined as the process whereby calcium and phosphate ions are supplied from a source external to the tooth to promote ion deposition into crystal voids in demineralized enamel, to produce net mineral gain. Recently, a range of novel calcium-phosphate-based remineralization delivery systems has been developed for clinical application. These delivery systems include crystalline, unstabilized amorphous, or stabilized amorphous formulations of calcium phosphate. These systems are reviewed, and the technology with the most scientific evidence to support its clinical use is the remineralizing system utilizing casein phosphopeptides to stabilize and deliver bioavailable calcium, phosphate, and fluoride ions. The recent clinical evidence for this technology is presented and the mechanism of action discussed. Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization show promise for the non-invasive management of dental caries.
The aim of this review was to compile recent evidence related to nanofilled resin composite materials regarding the properties and clinical performance. Special attention was given to mechanical ...properties, such as strength, hardness, abrasive wear, water sorption, and solubility. The clinical performance of nanocomposite materials compared with hybrid resin composites was also addressed in terms of retention and success rates, marginal adaptation, color match, and surface roughness. A search of English peer-reviewed dental literature (2003-2017) from PubMed and MEDLINE databases was conducted using the terms "nanocomposites" or "nanofilled resin composite" and "clinical evaluation." The list was screened, and 82 papers that were relevant to the objectives of this work were included in the review. Mechanical properties of nanocomposites are generally comparable to those of hybrid composites but higher than microfilled composites. Nanocomposites presented lower abrasive wear than hybrids but higher sorption values. Their clinical performance was comparable to that of hybrid composites.
Composites are increasing in popularity as restorative materials. This growing role indicates the necessity of studies on their clinical outcome. In this study, clinical studies published on the ...performance of posterior composite restorations were included except those of less than a 24‐month assessment period. Results of non‐vital, anterior or primary teeth and cervical single‐surface restorations were also excluded. Records about composite type, number of final recall restorations, failure/survival rate, assessment period and failure reasons were analysed for each decade. Overall survival/failure rates for studies in 1995–2005 were 89.41%/10.59% and for 2006–2016 were 86.87%/13.13%, respectively. In 1995–2005, the reasons for failure were secondary caries (29.47%) and composite fracture (28.84%) with low tooth fracture (3.45%) compared with reasons of failure in 2006–2016, which were secondary caries (25.68%), composite fracture (39.07%), and tooth fracture (23.76%). An increase in incidence of composite fracture, tooth fracture and need for endodontic treatment as failure reasons was noted in the latter decade in addition to a decrease in secondary caries, postoperative sensitivity, unsatisfactory marginal adaptation and wear. The overall rates of failure showed little difference, but the causes showed a notable change. This is believed to be a reflection of increased use of composites for larger restorations and possibly changes of material characteristics.
Abstract Objectives Demineralized dentin collagen release C-terminal cross-linked telopeptide (ICTP) and C-terminal peptide (CTX) during degradation. The present study evaluated the effects of dentin ...pre-treatment with K21, a quaternary ammonium silane (QAS), on matrix metalloproteinase (MMP) and cathepsin K-mediated collagen degradation. Methods Dentin beams were demineralized with 10% H3 PO4 for 24 h. After baseline dry mass measurements, the beams were divided into 5 groups (N = 10) according to protease inhibitors. The beams were pre-treated for 2 min with 2% chlorhexidine (CHX), 2%, 5% or 10% QAS; no pre-treatment was performed for the control group. The beams were subsequently incubated in calcium- and zinc-containing medium for 3, 7 or 14 days, after which changes in dry mass were measured and incubation media were examined for ICTP and CTX release. The MMP-2 and cathepsin K activities in QAS-treated dentin powder were also quantified using ELISA. Results The two factors (disinfectants and time) had a significant effect on dry mass loss, ICTP and CTX release (p < 0.001). The percentage of dry mass loss increased with time and was significantly lower in all experimental groups when compared to the control at 14 days (p < 0.001). Conversely, the rate of ICTP and CTX release was significantly lower in the experimental groups, compared to the uninhibited control at 7 and 14 days (p < 0.001). Dentinal MMP-2 and cathepsin K activities were significantly reduced after demineralized dentin was pre-treated with QAS. Conclusion The experimental QAS is a good inhibitor of MMP and cathepsin K activities in demineralized dentin. Clinical significance The newly developed antibacterial quaternary ammonium silane increases the resistance of dentin collagen to degradation by inhibiting endogenous matrix metalloproteinases and cysteine cathepsins. The quaternary ammonium silane cavity disinfectant is promising for use as a protease inhibitor to improve durability of resin-dentin bonds.
To determine the degree of surface staining of resin-based composites (RBCs) and glass-ionomer cements (GICs) after immersion in various stains and food-simulating solutions (FSS).
Six tooth-coloured ...restorative materials were used: a light-cured microfilled RBC (Durafil, Kulzer), a light-cured microglass RBC (Charisma, Kulzer), a polyacid-modified RBC (F2000, 3M/ESPE), a conventional GIC (Fuji IX, GC) and two resin-modified GICs (Fuji II LC, GC; Photac Fil, 3M/ESPE). Disk-shaped specimens were prepared and tested with either a matrix finish or polished using wet silicon carbide papers up to 2000 grit. All specimens were immersed in 37
°C distilled water for 1 week, followed by three different FSS (water, 10% ethanol, Crodamol GTCC) and five stains (red wine, coffee, tea, soy sauce and cola) for a further 2 weeks. Three specimens of each material for each stain were tested. Colour coefficients (CIE
L*
a*
b*) were measured by a spectrophotometer after each treatment. The change in colour (Δ
E
n
) was calculated using the formula:
Δ
E
n
=
(
Δ
L
n
+
(
Δ
a
n
)
2
+
(
Δ
b
n
)
2
1
/
2
Distilled water caused no perceptible colour change as tested by ANOVA and Tukey's tests. The effect of surface finish on staining was not statistically significant (
P>0.05). There was no strong interaction between FSS and stains or between FSS and materials. There was a strong interaction between surface and material, and stain and material (
P<0.001).
All materials were susceptible to staining by all stains especially coffee, red wine and tea; Fuji IX showed the least susceptibility and F2000 the greatest.
Abstract Objective The present study examined the effect of a quaternary ammonium silane (QAS) cavity disinfectant on the viability of human dental pulp cells, dentine bond durability and nanoleakage ...of simplified etch-and-rinse adhesives. Methods Etched dentine surface of third molars were randomly divided into two adhesive groups, Adper™ Single Bond 2 and Prime & Bond® NT™. For each adhesive, the teeth were randomly assigned to five cavity disinfectant groups ( N = 6): Group 1: deionised water (control); Group 2: 2% chlorhexidine (CHX); Group 3: 2% QAS; Group 4: 5% QAS and Group 5: 10% QAS. The cavity disinfectants were applied on etched dentine surfaces for 20 s, followed by adhesive application. The bonded teeth were sectioned for bond strength testing at 24 h, 6 months and 12 months. Viability of human dental pulpal cells was examined using MTT assay. Bond strength data were analysed using 3-way ANOVA and Tukey test. Interfacial nanoleakage was evaluated after 24 h and 12 months and analysed using Kruskal–Wallis test. Results Significant differences in bond strength were observed for the factors disinfectants ( p < 0.001) and time ( p < 0.001); while the factor, adhesive, was not significantly different ( p = 0.203). The 2% QAS cavity disinfectant preserved bond strength of both adhesives and reduced interfacial nanoleakage after 12 months. Cell viability was the lowest for 2% CHX, followed by 2% QAS and the control. Conclusions The 2% QAS cavity disinfectant demonstrated greater cell viability compared to 2% CHX, with no adverse effect on immediate bond strength and preserved bond stability over time. Clinical significance Incorporation of 2% quaternary ammonium silane cavity disinfectant in the resin–dentine bonding protocol enhances the success rate of bonded restorations.
Background
Evidence is lacking concerning the suitability of using bovine dentine in endodontic research. This study compared the mechanical properties of human and bovine root dentine using ...endodontic medicaments and irrigants.
Methods
Standardized human and bovine dentine bars were allocated to six experimental groups (n = 15): calcium hydroxide paste (Calasept® Plus); Odontopaste®; 0.5% and 1% NaOCl gels; 1% and 4% NaOCl solutions. The bars were exposed to the materials for 7 days and then immediately subjected to a three‐point bend test and Vickers microhardness test. Data were analysed using analysis of variance with Fisher's pairwise comparisons, with P < 0.05.
Results
Human dentine displayed a significantly higher modulus of elasticity (P = 0.001), higher microhardness (P < 0.001), and lower flexural strength (P = 0.004) compared with bovine dentine. Calcium hydroxide and Odontopaste® did not result in a significant change to the mechanical properties of human dentine. In human dentine, 0.5% NaOCl gel caused a significant decrease in flexural strength (P < 0.001) and microhardness (P = 0.02).
Conclusions
Bovine dentine was a suitable substrate relative to human dentine. The use of a 0.5% or 1% NaOCl gel as an intracanal medicament is not supported by this study.
Dental caries is a highly prevalent diet-related disease and is a major public health problem. A goal of modern dentistry is to manage non-cavitated caries lesions non-invasively through ...remineralization in an attempt to prevent disease progression and improve aesthetics, strength, and function. Remineralization is defined as the process whereby calcium and phosphate ions are supplied from a source external to the tooth to promote ion deposition into crystal voids in demineralized enamel, to produce net mineral gain. Recently, a range of novel calcium-phosphate-based remineralization delivery systems has been developed for clinical application. These delivery systems include crystalline, unstabilized amorphous, or stabilized amorphous formulations of calcium phosphate. These systems are reviewed, and the technology with the most scientific evidence to support its clinical use is the remineralizing system utilizing casein phosphopeptides to stabilize and deliver bioavailable calcium, phosphate, and fluoride ions. The recent clinical evidence for this technology is presented and the mechanism of action discussed. Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization show promise for the non-invasive management of dental caries. PUBLICATION ABSTRACT
This study investigated the hardness and color stability of five resin composites subjected to different polishing methods following immersion in distilled water or lactic acid for up to three ...months.
Three nanohybrid, Paradigm (3M ESPE), Estelite Sigma Quick (Tokuyama), Ice (SDI), and two microhybrid, Filtek P60 and Filtek Z250, composites were examined. Disc-shaped specimens (10×1.5 mm) were prepared and immersed in distilled water for 24 hours then polished using either silicon carbide paper, the Shofu polishing system or were left unpolished (control). The CIE values and microhardness were determined using a spectrophotometer and digital Vickers hardness tester, respectively (n=10) after one, 45, and 90 days of storage in distilled water or lactic acid. Data were analyzed using analysis of variance, Tukey test, and Pearson correlation coefficient.
Ice exhibited the greatest color change, yet Paradigm and Filtek P60 demonstrated the least. Overall, discoloration of tested materials was multifactorial and the effect of storage media depended on the material, polishing method and time interval. The greatest hardness was obtained for Paradigm and the lowest for Estelite. Hardness was found to be significantly higher in lactic acid after 45 days (
=0.014) and even higher after 90 days (
<0.001) compared with distilled water.
An acidic environment did not adversely affect color stability or microhardness of the resin composites. There was a significantly mild reverse correlation between hardness and color change in both storage media.
Background
This study evaluated the antimicrobial effect of a silver diamine fluoride (SDF)/potassium iodide (KI) product (Riva Star) on the viability of intratubular bacteria.
Methods
Forty‐five ...dentine discs prepared from caries‐free maxillary premolars were randomly divided into nine groups. Group 1 (negative control) contained non‐infected sound dentine discs. The remaining discs were infected with Streptococcus mutans suspension and received dentine treatments as follows: Group 2 (positive control), discs were left untreated; Group 3 SDF/KI (Riva Star); Group 4 chlorhexidine (CHX); Group 5 CHX + SDF/KI; Group 6 Carisolv; Group 7 Carisolv + SDF/KI; Group 8 Papacarie, and Group 9 Papacarie + SDF/KI. The discs were then fractured into two halves, stained with fluorescent LIVE/DEAD stain and observed using confocal laser scanning microscopy.
Results
SDF/KI exhibited a potent antibacterial effect, as represented by a significantly higher percentage of dead bacteria, in comparison with Carisolv and Papacarie (p < 0.05). The application of SDF/KI following Carisolv and Papacarie chemomechanical caries removel gels significantly reduced the viability of intra‐tubular bacteria in these groups.
Conclusions
The use of the silver diamine fluoride/potassium iodide product is effective in reducing the numbers of S. mutans in dentinal tubules infected with this organism.
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