Effect of CPP-ACP modified-GIC on prevention of demineralization in comparison to other fluoride-containing restorative materials.

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.

A laboratory study to test the responses of human dental pulp stem cells to extracts from three dental pulp capping biomaterials.

AIM: This laboratory study aimed to investigate the effects of three endodontic biomaterials; MTA-HP, iRoot-BP-Plus and ACTIVA on the proliferation, adhesion and osteogenic differentiation of human Dental Pulp Stem Cells (hDPSCs). METHODOLOGY: The hDPSCs were isolated from the dental pulps of 21 patients scheduled for surgical extraction of their impacted third molars. The MTT assay was used for assessing cellular proliferation. Ninety-six-well plates were used and the experiment was repeated four times under the same condition and the assay was done in triplicate. Four groups were assigned in which the hDPSCs were cultured in complete media only and considered as negative control. Whilst in the 2nd , 3rd and 4th groups, the cells were treated with CM supplemented with 1.5 µl MTA-HP (CM-MTA, iRoot-BP-Plus (CM-BP), and ACTIVA(CM-AC) extracts, respectively. Attachment adhesion and growth morphology of hDPSCs were observed using SEM and the osteogenic differentiation assay was evaluated by Alizarin red stain test (ARS). The data of proliferation and osteogenic differentiation were analysed using two-way ANOVA followed by Tukey's post hoc multiple comparison test. A p-value < 0.05 was considered significant to analyse the differences amongst the means of groups. RESULTS: Both CM-MTA and CM-BP groups were associated with a significant increase in hDPSC proliferation in comparison with CM-AC and CM groups (p = 0.001). hDPSCs exhibited a greater cellular attachment to iRoot-BP-Plus surfaces followed by MTA-HP, whilst less attachment was observed in the ACTIVA group. Moreover, at day 7 there was a significant difference in formation of mineralizing nodules; CM-BP, CM-MTA and CM-AC groups respectively (p = 0.001). Whilst there was no significance of difference between CM-AC and CM groups (p > 0.05). CONCLUSIONS: In a laboratory setting, ACTIVA, MTA-HP and iRoot-BP-Plus promoted hDPSCs proliferation, mineralization and attachment, which may explain their in-situ success as endodontic biomaterials.

Systematic Review and Meta-Analysis of Randomized Clinical Trials on Chemomechanical Caries Removal.

OBJECTIVES: The aim of this review was to assess the methodologies used in previously published prospective randomized clinical trials on chemomechanical caries removal and to conduct a meta-analysis to quantify the differences in the excavation time between chemomechanical and conventional caries removal methods. METHODS: An electronic search was performed using Scopus, PubMed, EBSCO host, and Cochrane Library databases. The following categories were excluded during the assessment process: non-English studies published before 2000, animal studies, review articles, laboratory studies, case reports, and nonrandomized or retrospective clinical trials. The methodologies of the selected clinical trials were assessed. Furthermore, the reviewed clinical trials were subjected to meta-analysis for quantifying the differences in excavation time between the chemomechanical and the conventional caries removal techniques. RESULTS: Only 19 randomized clinical trials fit the inclusion criteria of this systematic review. None of the 19 reviewed trials completely fulfilled Delphi's ideal criteria for quality assessment of randomized clinical trials. The meta-analysis results revealed that the shortest mean excavation time was recorded for rotary caries excavation (2.99±0.001 minutes), followed by the enzyme-based chemomechanical caries removal method (6.36±0.08 minutes) and the the hand excavation method (atraumatic restorative technique; 6.98±0.17 minutes). The longest caries excavation time was recorded for the sodium hypochlorite-based chemomechanical caries removal method (8.12±0.02 minutes). CONCLUSIONS: It was found that none of the current reviewed trials fulfilled all the ideal requirements of clinical trials. Furthermore, the current scientific evidence shows that the sodium hypochlorite-based (Carisolv) chemomechanical caries removal method was more time consuming when compared to the enzyme-based (Papacarie) chemomechanical and the conventional caries removal methods. Further prospective randomized controlled clinical trials evaluating the long-term follow-up of papain-treated permanent teeth are needed.

Effect of silver diamine fluoride and potassium iodide on residual bacteria in dentinal tubules.

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.

Current update of chemomechanical caries removal methods.

Chemomechanical caries removal is an excellent method for minimally invasive caries excavation, and the removal agents are either sodium hypochlorite (NaOCl)- or enzyme-based. The NaOCl-based agents include GK-101, GK-101E (Caridex) and Carisolv, and the enzyme-based agents include Papacarie and the experimental material, Biosolv. This review outlines the changes in chemomechanical caries removal methods and focuses on recently published laboratory and clinical studies. The historical development, mechanism of action, excavation time and biological effects on pulp and dental hard tissues are described. Based on existing evidence, the currently available chemomechanical caries removal methods are viable alternatives to conventional rotary instrument methods. Chemomechanical methods could be extremely useful in very anxious, disabled and paediatric patients. It does seem some of these agents would still benefit from quicker excavation times in order to achieve more universal acceptance. However, as a means of conserving the caries-affected dentine, chemomechanical caries removal is possibly much more successful than conventional rotary instrumentation.

Effect of dentine conditioning on adhesion of resin-modified glass ionomer adhesives.

BACKGROUND: The aim of this study was to investigate the use of phosphoric acid as a surface treatment compared to traditional conditioning agents to dentine bonded with resin-modified glass ionomer (RMGIC) adhesives. METHODS: Forty human molars were utilized in microtensile bond strength testing, while another 16 were used for evaluation of the bonded interface with scanning electron microscopy. Three RMGIC adhesives were evaluated: Fuji Bond LC (GC Corp); Riva Bond LC (SDI Ltd); and Ketac N100 (3M-ESPE). Surface treatments were 37% phosphoric acid (5 s) or 25-30% polyacrylic acid (PAA) (10 s), or the manufacturer's method - Fuji Bond LC: Cavity Conditioner (20% PAA + 3% AlCl3 10 s) or Ketac N100 primer: Ketac Nano priming agent (15 s). Teeth were finished with 600-grit SiC paper, surfaces treated and bonded with RMGIC adhesive and stored in distilled water for 24 h then subjected to microtensile bond strength testing. RESULTS: Two-way analysis of variance (ANOVA) revealed adhesion was affected by the 'type of RMGIC adhesive' and 'method of dentine surface treatment' (p < 0.05). The microtensile bond strength of Ketac N100 primer groups was lower than Fuji Bond LC and Riva Bond LC (p < 0.05). CONCLUSIONS: For RMGIC adhesives a brief etch with phosphoric acid does not adversely effect short-term bond strengths, but is no better than traditional conditioning with PAA.

Chemical, morphological and microhardness changes of dentine after chemomechanical caries removal.

BACKGROUND: This study compared the chemical, morphological and microhardness changes in carious dentine following application of NaOCl-based (Carisolv), papain-based (Papacarie) chemomechanical caries removal agents with conventional rotary method. METHODS: Thirty-two carious and eight non-carious human permanent molars were used. The carious molars were randomly distributed into four groups: Group 1 (positive control) - molars were left without caries removal; Group 2 - caries excavated with rotary method; Group 3 - caries excavated with Carisolv; Group 4 - caries excavated with Papacarie. Group 5 (negative control) consisted of eight sound molars. After caries excavation, all specimens were prepared for chemical, morphological analysis and Vickers hardness testing. RESULTS: EDX analysis showed no significant difference in Ca wt%, P wt% and Ca/P ratio among Groups 2 to 5. Vickers hardness of dentine from Groups 3 and 4 was significantly lower (p < 0.05) than for Groups 2 and 5. The use of Papacarie resulted in a dentine surface without smear layer and patent tubules, while Carisolv resulted in a dentine surface exhibiting two patterns: (1) the presence of smear layer or (2) patent tubules with partial smear layer formation. CONCLUSIONS: Papain-based (Papacarie) chemomechanical caries removal method is a reliable alternative to conventional rotary and NaOCl-based (Carisolv) caries removal.