Remineralizing Potential of Clinpro® and Tooth Mousse Plus® on Artificial Carious Lesions.

BACKGROUND: Calcium phosphate and fluoride (F) delivery systems claim to facilitate enamel remineralization. AIM: To evaluate and compare (i) the remineralizing potential of Clinpro® Tooth Crème(CTC) and Tooth Mousse Plus®(TMP) on artificial carious lesions, and (ii) the benefit of 1000ppm F dentifrice prior to the application of CTC and TMP. STUDY DESIGN: Carious lesions, 200-300µm deep were produced by placing molars in demineralizing solution for 96h, sections 100-150µm thick were then randomly assigned to six groups(n=150). Specimens were treated thrice daily with a non-fluoridated(Group A), or fluoridated dentifrice[1000ppm, (Group B)], or CTC(Group C), TMP(Group D), fluoridated dentifrice followed by CTC(Group E), or a fluoridated dentifrice followed by TMP(Group F), and then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography. RESULTS: Posttreatment maximum mineral content at the surface zone(Vmax) was significantly increased in Groups B, C, and D compared to the other groups. The lesion depth(LD) decreased in Group D>Group C>Group E, and the net mineral content gain(ΔZ) in Group C>Group D, which did not reach statistical significance. CONCLUSIONS: CTC and TMP exhibited similar efficacy in remineralizing artificial carious lesions. Nevertheless, the net mineral gain or lesion consolidation following CTC use was higher than TMP.

Remineralizing potential of a 60-s in vitro application of Tooth Mousse Plus.

BACKGROUND: No published studies exist on the remineralizing potential of Tooth Mousse Plus® (TMP) when applied for less than 3 min. AIM: To evaluate (i) the remineralizing potential of TMP on artificial carious lesions, when applied thrice daily for 60 s, and (ii) the benefit of using a fluoridated dentifrice prior to TMP application. DESIGN: Carious lesions, 120-200 µm deep, were produced by placing molars in demineralizing solution for 96 h, and sections 100-150 µm thick were then randomly assigned to four groups. Specimens were treated thrice daily with a non-fluoridated (Group A), or 1000 ppm F dentifrice (Group B), or TMP (Group C), or a 1000 ppm F dentifrice followed by TMP application (Group D), and then subjected to a 10-day pH cycling model. Lesion evaluation involved polarizing light microscopy and microradiography. RESULTS: Post-treatment maximum mineral content at the surface zone (Vmax ) was significantly increased and lesion depth (LD) significantly decreased in Group C, while only the Vmax increased in Group D. Increase in LD was observed in Group B; however, no significant differences were noted in percentage LD changes between groups B, C, and D (P > 0.05). CONCLUSIONS: TMP applied for 60 s significantly remineralized the artificial carious lesions. No additional benefit was evident when TMP was preceded by treatment with 1000 ppm F dentifrice.

Orofacial viral infections--an update for clinicians.

UNLABELLED: Orofacial viral infections may be less common but appear in different clinical forms. Often these infections get initially treated by antibiotics which obviously will have limited or no effect. The authors review the current concepts of orofacial viral infections, causative agents, their classification and clinical manifestations and a basis for treatment. CLINICAL RELEVANCE: Most viral infections do not require any specific treatment except in patients who are immunosuppressed or immunodeficient. Appropriate diagnosis and timely management of orofacial viral lesions are important irrespective of whether it is localized or a manifestation of a systemic infection.

Remineralization of initial enamel carious lesions using fluoridated milk in vitro.

OBJECTIVES: Milk is a universal dietary component and it is now recognized as an effective medium for the delivery of fluoride (F). This study sought (i) to evaluate fluoridated milk (2.5 ppm, 5 ppm, 10 ppm) for remineralizing carious lesions and (ii) to determine the optimum frequency for treating carious lesions with fluoridated milk. MATERIALS AND METHODS: Artificial carious lesions, 90-180 µm deep, were created on extracted third molar teeth that were sectioned to produce specimens of 100-120 µm thickness. Specimens were randomly divided into 13 groups (n = 20) for treatment with deionized water, plain milk or fluoridated milk (2.5 ppm, 5 ppm, 10 ppm); once daily, twice daily or on alternate days as part of a 20-day pH cycling model. Lesion depth (LD) and mineral content were evaluated before and after pH cycling. Paired t-test, ANOVA and Student-Newman-Keuls tests were employed to make comparisons within and between the different groups. RESULTS: Fluoridated milk significantly reduced LD and increased the mineral content of the lesions compared to plain milk and deionized water (p < 0.05). The greatest reduction in LD was with 2.5 ppm F milk used twice daily (p < 0.05). CONCLUSIONS: Milk with 2.5 ppm F used twice daily demonstrated the greatest remineralization of artificial enamel carious lesions in vitro.

Comparison of the remineralizing potential of child formula dentifrices.

BACKGROUND: Although child formula fluoridated dentifrices can be used safely by young children their remineralizing capability remains questionable. AIMS: To evaluate the remineralizing potential of child formula dentifrices on primary teeth. DESIGN: In vitro single-section technique utilizing a 7 days pH-cycling model. METHODS: Primary teeth were placed in demineralizing solution for 96 h to produce artificial carious lesions 100 µm deep, and then cut longitudinally into 50 sections 100-150 µm thick and randomly assigned to five groups. Sections in Groups A to D were treated with dentifrices containing 500 ppm AmF, 500 ppm MFP, 500 ppm MFP and xylitol, or 500 ppm NaF, respectively. Group E sections were treated with a nonfluoridated dentifrice. OUTCOME MEASUREMENTS: Lesions were evaluated using polarized light microscopy and microradiography. RESULTS: Group D (500 ppm NaF) sections exhibited a significant decrease in lesion depth, whereas those in Group E (nonF) showed a significant increase in depth (P<0.05, paired t-test). Decrease in lesion progression was observed in Groups A, B and C. CONCLUSIONS: The 500 ppm NaF dentifrice demonstrated remineralization of carious lesions by virtue of a significant decrease in lesion depth; whereas dentifrices that contained AmF, MFP and MFP with xylitol decelerated the progression of demineralization.

Fetal alcohol syndrome: case report and review of the literature.

Due to the significant increase in the incidence and prevalence of the fetal alcohol syndrome (FAS) in developing and developed nations, it is important that dental professionals recognize this condition. Patients with FAS have orofacial characteristics and various psychological and physical symptoms that may affect a dental treatment plan. This article reviews the prevalence, incidence, alcohol dose response and metabolism, and clinical characteristics of FAS. A case demonstrating moderate signs of the condition is included to illustrate some of the characteristics.

Application of biologically-oriented dentin bonding principles to the use of endodontic irrigants.

PURPOSE: To compare the removal of smear layer and the structure of the hybrid layer formed after the use of EDTA or MTAD solutions when used as a final flush. METHODS: Single-rooted extracted premolars (n=18) were collected and treated for root canal therapy using NaOCl irrigation followed by a final rinse of 17% EDTA, Biopure MTAD, or saline (negative control). The roots were obturated with gutta-percha and a hydrophilic HEMA-containing root canal sealer. The TEM specimens were impregnated with 50% silver nitrate to visualize sealing imperfections and nanoleakage. The structure of the coronal, middle and apical parts of root canal walls was examined using transmission electron microscopy. RESULTS: After NaOCl irrigation, a final rinse with BioPure MTAD or 17% EDTA completely removed the 2 microm-thick smear layer on mechanically instrumented root canal walls. The BioPure MTAD hybrid layer was thicker than the 17% EDTA hybrid layer. Both the BioPure MTAD and EDTA caused a collapse of the dentin matrix structure which impeded sealer infiltration and the formation of high quality hybrid layer bonding. The hybrid layers created in smear layer-covered dentin exhibited less potential for nanoleakage than the MTAD or EDTA hybrid layers.

Effect of resin hydrophilicity on tracer penetration. A preliminary study.

PURPOSE: To evaluate, by transmission electron microscopy, the extent of silver nitrate penetration into four polymerized resin blends with increasing degree of hydrophilicity after a period of 24 hours. METHODS: The uncured resin was polymerized in an experimental composite inlay processing chamber under a pressurized nitrogen atmosphere maintained at 551.6 KPa and light-activated for one complete cycle at 125 degrees C for 10 minutes. The resin blocks were sectioned occluso-gingivally into multiple 0.9 x 0.9 x 5 mm resin beams, and immersed in 50% basic, ammoniacal silver nitrate for 24 hours, exposed to a photodeveloping solution and prepared for transmission electron microscopy. The percentage distributions of silver deposits were compared using Kruskal-Wallis one-way analysis of variance (ANOVA) on ranks and Dunn's multiple comparison tests. RESULTS: No silver uptake occurred in the two most hydrophobic resins (Groups 1 & 2). The percentage distributions of silver deposits in the more hydrophilic Group 3 (6.23 +/- 1.35%) and 4 (5.08 +/- 1.09%) resins were significantly higher (P < 0.05) than were found in the more hydrophobic resins but Groups 3 and 4 were not significantly different from each other. The intensity of silver uptake increased with hydrophilicity of the resin blends. TEM examination revealed two types of silver deposits: fine spotted-type silver grains, and islands of interconnecting electron-dense clusters of silver grains. Phase separation of resin components was observed in Group 4 resin blends.

In vitro model for evaluating the effect of child formula toothpastes on artificial caries in primary dentition enamel.

PURPOSE: To determine if the in vitro 10-day pH-cycling model used for permanent teeth could be utilized to evaluate de/remineralization effects, on the enamel of primary teeth, of child formula toothpastes. METHODS: Sound extracted primary anterior teeth were coated with nail varnish, leaving a 1 mm-wide window prior to being placed in a demineralizing solution to produce artificial carious lesions in enamel. The teeth were subsequently cut longitudinally into 100 microm thick sections. The 72 specimens were randomly assigned to six groups. In Set 1 contained the specimens in Group a, which were treated with a pea-sized (0.32 g) quantity of non-fluoride toothpaste (First Teeth), and Groups b and c which were treated with half and pea-sized (0.16 g) quantities of fluoridated toothpaste (Colgate), and cycled for 10 days. The specimens in Set 2 (Groups A, B and C) were similarly treated but subjected to 7-day pH-cycling. RESULTS: After Day 8 the lesions in Set 1 extended into dentin and so could not be evaluated. Polarized light microscopy and microradiography were used to evaluate the lesions subjected to 7-day pH-cycling. Lesions in Groups A and B increased in depth and area by approximately 50%, while those in Group C increased in depth and area by 20%; however, no statistically significant differences occurred between the groups. If this model pH cycling is to be used for primary teeth, a reduction from 10 to 7 days in length should be considered.

Single-step, self-etch adhesives behave as permeable membranes after polymerization. Part III. Evidence from fluid conductance and artificial caries inhibition.

PURPOSE: To test the hypothesis that formation of inhibition zones by bonded restorations in artificially-induced carious dentin lesions is related to the permeability of the self-etch adhesives. METHODS: Fluid conductance of four single-step self-etch adhesives (Prompt L-Pop, Etch&Prime 3.0, One-Up Bond F and Reactmer Bond), and a control two-step self-etch adhesive (UniFil Bond) were measured after sound dentin surfaces were:(1) acid-etched; (2) polished to produce smear layers; (3) bonded with the adhesive; each at 20 cm hydrostatic pressure (hp). Osmotic fluid conductance was also determined for the bonded dentin after immersion in 4.8 M CaCl2 at 0 cm hp. For artificial caries inhibition, a non-fluoride releasing (NFR) two-step self-etch adhesive (UniFil Bond) and a fluoride-releasing (FR) single-step adhesive (Reactmer Bond) were used in combination with a NFR composite (Metafil CX) or a FR restorative material (Reactmer Paste). Artificial caries were induced in these restorations, from which 120 +/- 10 microm thick sections and the effect of caries inhibition were quantitatively assessed with polarizing light microscopy and image analysis. RESULTS: Fluid conductance after bonding with the single-step adhesives Prompt L-Pop and Etch&Prime 3.0 were not significantly different from those recorded from smear layer-covered dentin. Although better seals were achieved with One-Up Bond F and Reactmer Bond, fluid conductance at 20 cm hp was significantly higher than the two-step self-etch adhesive UniFil Bond. Osmotic conductance at 0 cm hp were not significantly different from normal fluid conductance at 20 cm hp. The sizes of artificial carious lesions in UniFil Bond were significantly higher irrespective of whether a FR or NFR composite was used. Significant reduction in lesion size occurred in Reactmer Bond with the use of a NFR composite, and even more so with the use of a FR composite.

Submicron hiati in acid-etched dentin are artifacts of desiccation.

OBJECTIVES: The submicron hiatus represents a potential space between the base of the collagen network and the mineralized dentin when dentin is acid-etched for bonding. These spaces were observed in SEM studies after acid-etched dentin specimens were critical point dried or dehydrated in hexamethyldisilasane. However, they have never been identified in TEM studies of dentin hybrid layers. This study critically examined the cause of submicron hiati formation using a silver staining technique to measure nanoleakage. METHODS: Two multi-step, total-etch adhesives (One-Step, Bisco; Single Bond, 3M) and two single-step, self-etching adhesives (Prompt L-Pop, ESPE; One-Up Bond F, Tokuyama) were examined. Flat dentin surfaces were bonded with these adhesives and a lining composite. In each adhesive group, 0.8mm thick slabs from the same bonded tooth were coated with nail varnish applied 1mm from the bonded interfaces. The varnish was either left to dry completely for 10min before immersing in 50wt% silver nitrate (AgNO(3)) for 24h (group D), or painted on blotted tooth slabs that were immediately dropped into the AgNO(3) solution (group M). After developing, undemineralized, unstained, epoxy resin-embedded sections were prepared for transmission electron microscopy (TEM) to identify the amount and distribution of silver uptake. RESULTS: Nanoleakage patterns were observed in all adhesive-bonded teeth, regardless of brand. Fine reticular silver deposits were also found in the underlying undemineralized dentin. In group D, submicron hiati were seen as tunnels of heavy silver deposits beneath hybrid layers. Specifically, a hiatus occurred between the undemineralized intertubular dentin and a cohesively fractured layer of the same matrix that was attached to the base of the hybrid layer. Hiati were completely absent in group M, regardless of the brand of adhesive. SIGNIFICANCE: Submicron hiati are artifacts created by desiccation during specimen processing, and should be referred to as such in future studies of bonded dentin interfaces.

Single-step adhesives are permeable membranes.

OBJECTIVES: This study tested the hypotheses that micro-tensile bond strengths of all currently available single-step adhesives to dentine are adversely affected by delayed activation of a light-cured composite, and that such a phenomenon only occurs in the presence of water from the substrate side of the bonded interface. METHODS: In experiment I, a control three-step adhesive (All-Bond 2, Bisco) and six single-step adhesives (One-Up Bond F, Tokuyama; Etch&Prime 3.0, Degussa; Xeno CF Bond, Sankin; AQ Bond, Sun Medical; Reactmer Bond, Shofu and Prompt L-Pop, 3M ESPE) were bonded to sound, hydrated dentine. A microfilled composite was placed over the cured adhesive and was either light-activated immediately, or after leaving the composite in the dark for 20 min. In experiment II, three single-step adhesives (Etch&Prime 3.0, Xeno CF Bond and AQ Bond) were similarly bonded to completely dehydrated dentine using the same delayed light-activation protocol. In experiment III, a piece of processed composite was used as the bonding substrate for the same three single-step adhesives. The microfilled composite was applied to the cured adhesives using the same immediate and delayed light-activation protocols. Bonded specimens were sectioned for micro-tensile bond strength evaluation. Fractographic analysis of the specimens was performed using SEM. Stained, undemineralised sections of unstressed, bonded specimens were also examined by TEM. RESULTS: When bonded to hydrated dentine, delayed light-activation had no effect on the control three-step adhesive, but significantly lowered the bond strengths of all the single-step adhesives (p < 0.05). This adverse effect of delayed light-activation was not observed in the three single-step adhesives that were bonded to either dehydrated dentine or processed composite. Morphological manifestations of delayed light-activation of composite in the hydrated dentine bonding substrate were exclusively located along the composite-adhesive interface, and were present as large voids, resin globules and honeycomb structures that formed partitions around a myriad of small blisters along the fractured interfaces. CONCLUSION: These features resembled the 'overwet phenomenon' that was previously reported along the dentine-adhesive interfaces of some acetone-based three-step adhesives. The cured adhesive layer in single-step adhesives may act as semi-permeable membranes that allow water diffusion from the bonded hydrated dentine to the intermixed zone between the adhesive and the uncured composite. Osmotic blistering of water droplets along the surface of the cured adhesive layer and emulsion polymerisation of immiscible resin components probably account for the compromised bond strength in single-step adhesives after delayed activation of light-cured composites.