The aim of this literature review is to explore the treatment methods for root caries in laboratory and clinical research in the last decade. A systematic search of publications in PubMed and Web of ...Science databases was performed. The timespan was limited to the last 10 years and English language. Further retrieval was conducted using the search terms of specific therapies or treatments. Eighty‐two articles were included in this systematic review and full texts were retrieved. Types of studies included laboratory studies and clinical trials. Therapeutic approaches for root caries without risk of pulp exposure can be categorized into non‐invasive and restorative treatment. Non‐invasive treatments which targeted different causative factors of root caries have been developed in the last decade. Accordingly, several artificial caries model systems have been proposed for the study of root caries in the laboratory. Carious tissue excavation techniques and restorative materials and procedures have been modified to improve the prognosis of invasive treatment. It is of importance to determine the most appropriate therapy for root caries and further clinical trials are needed to draw firm conclusions concerning the efficacy and consistency of the various treatment methods proposed.
Background
This study investigated the physical properties and ion release of casein phosphopeptide‐amorphous calcium phosphate (CPP‐ACP)‐modified calcium silicate‐based cements (CSCs) and compared ...the properties of a trial mineral trioxide aggregate (MTA) with two commercially available CSCs, Biodentine™ and Angelus® MTA.
Methods
The setting time, solubility, compressive strength and Vickers surface microhardness of the three CSCs incorporated with 0%, 0.5%, 1.0%, 2.0% and 3.0% (w/w) CPP‐ACP were investigated. Release of calcium (Ca2+), phosphate ions (Pi) and pH of the test cements were measured after 24, 72, 168 and 336 h of storage.
Results
The addition of up to 1.0% CPP‐ACP into Biodentine™ and 0.5% into the other cements did not adversely affect their physical properties except for the setting time. The addition of 0.5% CPP‐ACP increased Ca2+ released from Biodentine™ (after 168 and 336 h), Angelus® MTA (after 168 h) and the trial MTA (after 72 h). The addition of 1.0–3.0% CPP‐ACP increased Ca2+ and Pi released from all the cements. Biodentine™ released more Ca2+ particularly in the early stages and showed shorter setting time and higher mechanical properties than the other cements. The mechanical properties of Angelus® MTA and the trial MTA were similar. All the cements produced highly alkaline storage solutions.
Conclusions
Up to 1.0% CPP‐ACP in Biodentine™ improves Ca2+ and Pi release and 0.5% CPP‐ACP in Angelus® MTA and the trial MTA improves Ca2+ release without altering the mechanical properties and solubility. The addition of CPP‐ACP into CSCs prolonged the setting time.
This study compared the microshear bond strengths (MSBS) of four self-etching adhesives (Adper Scotchbond SE SSE, Clearfil SE Bond CSE, Clearfil S3 Bond CS3 and One Coat 7.0 OC) and an etch-and-rinse ...adhesive (Adper Single Bond Plus SB) when bonded to two conventional glass ionomer cements (GICs) (Fuji IX GP EXTRA and Riva Self Cure). The null hypothesis tested was there is no difference in the adhesive ability of an etch-and-rinse adhesive and self-etching adhesives when bonded to GIC for up to 6 months.
The GICs were embedded in type III dental stone and wet ground with 1200-grit SiC paper. Twenty specimens were bonded for each adhesive according to manufacturers' instructions with a 1.5-mm bonding diameter. Specimens were stored at 100% humidity for 24 hours, 1 month, or 6 months. Microshear bond strengths were obtained using a crosshead speed of 1 mm/min. The results were calculated and analyzed using analysis of variance (ANOVA) and Tukey HSD test.
SB had significantly lower MSBS than the four self-etching adhesives for all storage periods. MSBS at 6 months for SB was significantly lower than at 1 month. There were no significant differences in MSBS among the self-etching adhesives. Cohesive failure within GIC was the most common failure mode observed.
SB showed a lower bond strength than the self-etching adhesives when bonded to conventional GICs for all storage periods. This might be a result of the phosphoric acid etching. However, cohesive strength of GIC was a limiting factor for the MSBS outcomes.
Glass ionomer cements (GICs) are considered the material of choice for restoration of root carious lesions (RCLs). When bonding to demineralized dentin, the collapse of dentinal collagen during ...restorative treatment may pose challenges. Considering its acidic nature and collagen biomodification effects, proanthocyanidin (PAC) could be potentially used as a dentin conditioner to remove the smear layer while simultaneously acting to biomodify the dentinal collagen involved in the bonding interface. In this study, 6.5% w/v PAC was used as a conditioner for sound (SD) and laboratory demineralized (DD) root dentin before bonding to resin-modified GIC (FII), casein phosphopeptide–amorphous calcium phosphate (CPP-ACP)–modified GIC (FVII), or a high-viscosity GIC (FIX). Root dentin conditioned with deionized distilled water (DDW) or polyacrylic acid (PAA) served as controls. Results indicated FII showed higher shear bond strength (SBS) on SD than the other 2 GICs, especially in PAA-conditioned samples; FIX showed significantly higher SBS than FII and FVII on PAA- or PAC-conditioned DD. In each category of GIC, PAA and PAC did not have a significant influence on SBS in most cases compared to DDW except for a significant decrease in PAC-conditioned SD bonded to FII and a significant increase in PAA-conditioned DD bonded to FIX. The bonding interface between GIC and SD was generally more resistant to the acid-base challenge than DD. Although the alterations in failure modes indicated a compromised interfacial interaction between GICs and PAC-treated root dentin, biomodification effects of PAC on dentin were observed from Raman microspectroscopy analysis in terms of the changes in mineral-to-matrix ratio and hydroxyproline-to-proline ratio of dentin adjacent to the bonding interface, especially of DD. Results from this study also indicated the possibility of using in situ characterization such as Raman microspectroscopy as a complementary approach to SBS test to investigate the integrity of the bonding interface.
Background
This study compared natural root caries lesions with artificial root caries lesions prepared with one of the two demineralising solutions.
Methods
Twelve natural root caries lesions on ...upper incisors and 24 artificial root lesions were prepared on sound root surfaces using 50 mM acetic acid, 1.5 mM CaCl2, 0.9 mM KH2PO4 at pH 5.0 or 80 mL/L Noverite K‐702 polyacrylate solution, 500 mg/L hydroxyapatite, 0.1 mol/L lactic acid at pH 4.8 (n = 12/group) for 96 hours. Lesions were scanned using micro‐CT. Inciso‐gingival oriented images were analysed and mineral density calculated at 7.5 μm increments from the surface to 225‐μm deep. Sectioned lesions were analysed by Knoop microhardness up to 250 μm from the lesion surface. Data were analysed by the Dunn's test with Bonferroni correction.
Results
Natural and artificial lesion mean mineral densities were not statistically different (P > 0.05). Mineral density from the surface to 75 μm was greater in natural lesions and from 150 to 225 μm was greater in artificial lesions (P < 0.05). Microhardness values were statistically higher in artificial lesions (P < 0.05); no difference was found among artificial lesions produced by the two solutions (P > 0.05). Mineral density and microhardness of natural and artificial root caries are different from each other. A greater mineralized surface layer existed on natural lesions.
Background
This study evaluated the ability of a CPP‐ACP‐modified Glass–ionomer cement (GIC) to inhibit demineralization around the margins of cervical cavities in natural teeth in comparison with a ...Giomer and conventional GIC with and without coating.
Methods
Thirty‐two sound human molars were used. Box‐shaped cavities were prepared along the CEJ. Teeth were randomly divided into four groups and restored with Equia Forte Fil, Coated Equia Forte Fil, Fuji VII EP or Beautifil II. Teeth were subjected to pH cycling. Micromorphological and elemental analyses were done using SEM and EDX. Polarized light microscope analysis and microhardness tests were also performed.
Results
Microhardness tests on enamel showed a significant difference between the coated Equia group, Equia and Beautifil II groups (P < 0.05). Dentine results showed significant differences between the coated Equia group and all other groups (P < 0.05). Elemental analysis showed significant differences in calcium weight percentage among the first and second observation levels in all groups (P < 0.05). A significant difference was found between the coated Equia group and the other three groups (P < 0.05).
Conclusions
All tested materials showed some ability to resist demineralization at the restoration margins. The coated GIC restoration showed better outcomes compared with the other tested materials.
Background
The aim of this study was to compare the flexural strength and Vickers hardness of tooth‐coloured restorative materials with and without applying a self‐adhesive coating for up to 6 ...months.
Methods
Specimens were prepared from three resin composites (RC), two resin‐modified glass‐ionomer cements (RM‐GIC) and two conventional glass‐ionomer cements (CGIC). All materials were tested both with and without applying G‐Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four‐point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope.
Results
Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent.
Conclusions
The load‐bearing capacity of the restorative materials was affected by applying self‐adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM‐GIC and RC.
The aim of the study was to determine the extent to which canal size, radius of curvature and proximal root concavity influence fracture susceptibility and pattern. A standardized cross-section of ...the mid-root region of a mandibular incisor was created by averaging the dimensions of 10 extracted teeth, and then the basic finite element analysis (FEA) model was created. By varying canal diameter, shape, and proximal concavity, these factors could be examined for roles in fracture susceptibility and pattern. The factors all interact in influencing fracture susceptibility and pattern, with dentin thickness not the only determining factor. The removal of dentin does not always result in an increased fracture susceptibility.
Background: The marginal ridge is considered fundamental to the ability of the tooth to resist functional and parafunctional occlusal loads without damage. Despite this role, very little is known of ...patterns of stress and strain in marginal ridges under load. This study investigated strains in proximal enamel of mandibular premolars using finite element analysis (FEA) and strain gauge measurements.
Methods: A three‐dimensional FEA model of a human mandibular premolar was developed using commercial FEA software, and strains were computed in response to loads simulating clenching and chewing functions. Strains were measured in extracted premolars using strain gauges mounted on the proximal surfaces, under similar occlusal loading conditions.
Results: Strains in the vicinity of contact areas and marginal ridges were lower than near the cementoenamel junction and on buccal and lingual surfaces. The magnitude of proximal strains increased with oblique loading on cuspal inclines. Finite element analysis results correlated well with strain gauge measurements and can be used to predict strain directions and magnitudes.
Conclusions: At least for mandibular premolars, the marginal ridges are not highly stressed areas during simulated occlusal loading.
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