Search

Limited evidence exists about the usefulness of ethanol or acetone application to desiccate caries lesions before resin infiltration. Therefore, this in vitro study aimed to compare the penetration depths (PD) of an infiltrant (DMG, Germany) into natural caries lesions using various pretreatments.Extracted permanent human molars and premolars showing non-cavitated caries lesions were etched (90 s, 15 % HCl gel) and stored in pooled saliva (7 days). Lesions were etched again (30 s, 15 % HCl gel), washed (30 s), air-dried (30 s), and randomly allocated to one of the pretreatments: none (negative control), air-drying (incubator, 37 °C, 24 h; positive control), once ethanol (E1), twice ethanol (E2), once acetone (A1), and twice acetone (A2). Subsequently, the infiltrant was applied for 5 min and light-cured. Ground sections were prepared for analyses of lesion depths (LD) and PD using confocal microscopy.Median LD (Q25/Q75) of all lesions (n = 91) and lesions ≥500 μm (n = 57) were 629 (395/798) and 731 (638/876) μm, respectively. When all lesions were analyzed, no significant differences between various pretreatments could be observed (p 0.05, Kruskal-Wallis). For lesions ≥500 μm, significantly deeper PP was observed in groups PC, E1, A1, and A2 compared with NC (p 0.05; Mann-Whitney), but not after adjustment for multiple comparison (p 0.05).Application of either ethanol or acetone, followed by air-drying, is suitable to prepare caries lesions for resin infiltration in vitro.This paper shows that proper drying is an important step prior to caries infiltration.

In the search for an ideal minimally-invasive multipotent postnatal stem cells' source, the aim of the present study was to isolate and characterize multipotent postnatal stem/progenitor cells from the human alveolar bone proper tissue of the oral cavity. Cells were isolated from human alveolar bone parts, immunomagnetically sorted using STRO-1 antibodies and characterized flow cytometrically for the expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1 surface markers. Colony-formation and multilineage differentiation potential were tested. Mineralized tissue marker expression was examined using real time polymerase chain reaction (PCR). The cells were plastic-adherent and showed colony-formation. Cells expressed the surface markers CD73, CD90, CD105, STRO-1 and CD146/MUC18, while lacking the expression of the hematopoietic markers CD14, CD34 and CD45. Cells could be differentiated into osteoblastic, adipocytic and chondroblastic lineages. Unstimulated cells expressed alkaline phosphatase (ALP), type I, III and V collagens, osteonectin and osteocalcin in a very distinctive pattern. This study presents a practical and minimally-invasive scheme for the isolation of multipotent postnatal stem/progenitor cells from the human alveolar bone tissue of the oral cavity.

This study evaluated the influence of the penetration coefficient (PC) and ethanol addition on the penetration depth (PD) of experimental infiltrants into proximal caries lesions in primary molars. Caries lesions (n = 45) were randomly treated with 1 of 4 experimental infiltrants (PC63; PC185; PC204; PC391) for 5 min. Lesion depths and PDs were analysed using dual fluorescence confocal microscopy. Lesions were almost completely infiltrated in all groups. Median PDs and percentage penetrations were not significantly different between groups (p > 0.05). When applied for 5 min, all tested infiltrants were able to infiltrate proximal caries in primary molars nearly completely.

Resin infiltration of non-cavitated proximal caries lesions has been shown to inhibit further demineralization. However, the effect of resin infiltration in cavitated lesions is unknown. Therefore, the aim of this in vitro study was to evaluate infiltration patterns of proximal caries lesions differing in International Caries Detection and Assessment System (ICDAS) codes. Extracted human molars and premolars showing proximal caries lesions with and without cavitations (ICDAS codes 2-5) were etched with 15% hydrochloric acid gel and resin infiltrated according to the manufacturer's instructions. Three sections from each lesion were prepared and analyzed using a dual-fluorescence staining technique and confocal microscopy. The dimensions of the demineralized and cavitated lesions areas, as well as the resin-infiltrated parts within these lesions, were measured. The demineralized parts were infiltrated from 73% to 100% (median values) but the cavities were filled only negligibly (0-5%). Teeth that had an ICDAS code of 5 showed a significantly lower percentage infiltration/filling of lesions compared to teeth with ICDAS codes of 2 and 3. It was concluded that under in vitro conditions the tested infiltrant penetrates most parts of the demineralized enamel but is not capable of filling up cavities and therefore the efficacy of caries infiltration, particularly in lesions with larger cavitations, might be impaired.

Resin infiltration is an innovative approach to arrest progression of caries lesions. The aim of this randomized split-mouth placebo-controlled clinical trial was to assess whether resin infiltration of proximal lesions is more effective than non-operative measures alone with respect to the inhibition of caries progression. In 22 young adults, 29 pairs of interproximal lesions with radiological extension into the inner half of enamel or the outer third of dentin were randomly allocated to two treatment groups. In the test group, lesions were infiltrated (Icon, pre-product; DMG). A placebo treatment was performed in the control group. All participants received instructions for diet, flossing, and fluoridation. The primary outcome after 18 months was radiographic lesion progression (assessed by digital subtraction radiography). No unwanted effects could be observed. In the effect group, 2/27 lesions (7%) and in the control group 10/27 lesions (37%) showed progression (p = 0.021; McNemar). Infiltration of interproximal caries lesions is efficacious in reducing lesion progression.

By limiting the resources that may be used to display each frame and distributing those resources among the crowd as a whole, we can guarantee that a crowd of any size may be rendered at interactive frame rates. The realism of this crowd may be maintained by sharing the available resources appropriately. Choosing points as the rendering primitive for lower detail representations allows us to distribute the available points among appropriate characters, something not possible with triangles, as they must maintain an explicit connectivity to represent an object.

Noninvasive (preventive) measures involving fluoridation, dietary control, and oral hygiene instruction, as well as invasive restorative methods, are the standard treatment options for interproximal caries. Intermediate treatment options, similar to pit-and-fissure sealing on occlusal surfaces that has been shown to be effective in preventing and inhibiting caries, have not yet been established on interproximal surfaces. Recently, the application of resins on interproximal caries lesions has been studied and improved, leading to the development of new materials, which infiltrate and seal the carious lesion, improving the inhibition of caries progression. Clinical data show this new technique complements existing treatment options for interproximal caries by delaying the time point for a restoration and consequently closing the gap between noninvasive and invasive treatment options.

This article describes a novel approach to treat smooth-surface white spot lesions micro-invasively. The technique is based on the infiltration of enamel caries lesions with low-viscosity light-curing resins called infiltrants. After the surface layer is eroded, the lesions are desiccated and a resin infiltrant is applied. The resin penetrates into the lesion micro-porosities driven by capillary forces and is subsequently hardened. Infiltrated lesions lose their whitish appearance and look similar to sound enamel. Additionally, the treatment prevents lesion progression. The proposed technique might be an alternative to microabrasion and restorative treatment, in particular for white spot lesions of esthetically relevant teeth.

So far approaches for caries treatment follow a dichotomized scheme: Non invasive options of primary and secondary prevention are contrasted to invasive treatment of caries lesions. Depending on the treatment philosophy of dentists and dental schools an early or late invasive treatment threshold is recommended. Sealing of proximal lesions as done in pit and fissures has only been established in some dental schools, so far. Moreover, infiltration of the enamel part of lesions could close the gap between preventive and invasive measures. Most of these novel treatment options for proximal surfaces are currently in the last stages of product development. With respect to the good clinical results of proximal sealing with conventional sealants, this regimen seems already be recommendable to hamper further lesion progression in clinical practice. Caries infiltration of lesions situated on proximal and other smooth surfaces might even be a more promising approach, if clinical studies corroborate the recent in vitro findings. All these novel limited invasive strategies might be suitable to complete the current dichotomized way of caries treatment.

To compare scanning electron microscopic (SEM) and confocal laser scanning microscopic analyses (CLSM) of hybrid layer thickness and the number of dentinal tubules penetrated with composite resin inside the root canal on identical samples.Central maxillary incisors were restored using fiber posts (FRC Postec) inserted with a chemically curing composite resin (Clearfil Core/New Bond). Two different fluorescent dyes were used to respectively label adhesive and composite resin. Each root was sectioned into two slices starting 2 mm below the cementoenamel junction. SEM (low vacuum mode) and CLSM (dual fluorescence mode) analyses of 18 samples were performed. Hybrid layer thickness was measured at five characteristic points of each sample and the number of dentinal tubules penetrated with composite resin was counted on both corresponding images by two independent observers. Correlation coefficients as well as pairwise comparisons were calculated for both parameters.SEM and CLSM measurements of hybrid layer thickness were positively correlated (r2 = 0.772; Pearson), and thickness was significantly higher after evaluation with CLSM (p0.0005; Wilcoxon). The observed number of dentinal tubules penetrated with composite resin revealed a nonsignificant correlation (r2 = 0.111; p = 0.193). Significantly lower tag numbers were counted when using SEM (p = 0.010; Wilcoxon).With respect to the variability of the hybrid layer measurements, the two methods yielded comparable results. CLSM provided more detailed information regarding the penetration and distribution of resin cement and adhesive than did SEM imaging.

In artificial lesions, improved penetration and the caries-inhibiting properties of infiltrating resins could be observed with increasing penetration coefficients (PCs). The aim of the present study was to compare the penetration abilities of an experimental ‘infiltrant’ into natural lesions with those of an adhesive in vitro. Extracted human molars and premolars showing proximal white spots were cut across the lesions perpendicular to the surface. Corresponding lesion halves were etched for 120 sec with 15% hydrochloric acid gel and were subsequently treated with either an adhesive (PC: 31 cm/sec) or an infiltrant (PC: 273 cm/sec). Specimens were observed by confocal microscopy and transverse microradiography. Penetration depths of the adhesive were significantly lower compared with those of the infiltrant (p < 0.001; Wilcoxon). It can be concluded that resins with higher PCs (infiltrants) show superior ability to penetrate natural lesions compared with resins with lower PCs.