In situ Acid Resistance of in vivo Formed White Spot Lesions

2000 ◽  
Vol 34 (5) ◽  
pp. 388-394 ◽  
Author(s):  
Y. Iijima ◽  
O. Takagi
Keyword(s):  
Acid Resistance ◽  
White Spot ◽  
White Spot Lesions

Mode of Action of Fluoride: Application of New Techniques and Test Methods to the Examination of the Mechanism of Action of Topical Fluoride

1994 ◽  
Vol 8 (2) ◽  
pp. 166-174 ◽  
Author(s):  
D.J. White ◽  
D.G.A. Nelson ◽  
R.V. Faller
Keyword(s):  
Acid Resistance ◽  
Test Methods ◽  
Magic Angle Spinning ◽  
Treatment Modalities ◽  
Magic Angle ◽  
Reaction Products ◽  
In Situ Experiments ◽  
Ph Cycling

Modern techniques in dental research continue to assist in the study of the mode of (anticaries) action of topical fluorides. The Plaque Glycolysis and Regrowth Model (PGRM) facilitates the standardized assessments of antimicrobial effects on plaque following use of test formulations in vivo without complications arising from coincident mineral reactivity. In vivo plaque glycolysis testing demonstrates that topically applied fluoride, at conventional levels found in dentifrices, has only modest effects on the metabolic (acid-producing) activity of dental plaque. Any 'plaque' contribution to fluoride efficacy must come from more subtle effects on plaque acidogenicity than those measured in PGRM. The 19-F MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance) technique provides unambiguous measures of the reaction products of F-enamel interactions. Studies have revealed a new 'reaction product' of fluoride-enamel interactions-designated as Non-Specifically-Adsorbed Fluoride, NSAF. This species, along with FAP (fluoroapatite), FHAP (fluorohydroxyapatite), and CaF2 (calcium fluoride), contributes to the remineralization/ demineralization benefits of fluoride. pH cycling and in situ denture chip studies permit quantitative assessments to be made of the relative benefits of fluoride in promoting remineralization and in inhibiting demineralization. Results from pH cycling/ in situ experiments are strongly supportive of Koulourides' 'Acquired Acid Resistance' concept, describing fluoride's decay-preventive effects. The continued application of new analytical/physical techniques and testing regimens to the study of fluoride anticaries mechanisms may lead to the development of improved fluoride agents/treatment modalities for the prevention of dental caries.

scholarly journals Camouflage effects following resin infiltration of postorthodontic white-spot lesions in vivo: One-year follow-up

2015 ◽  
Vol 85 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Amely Eckstein ◽  
Hans-Joachim Helms ◽  
Michael Knösel
Keyword(s):  
White Spot ◽  
White Spot Lesions ◽  
Female Ratio ◽  
Significance Level ◽  
Resin Infiltration ◽  
Male Female Ratio ◽  
The Difference ◽  
One Year

ABSTRACT Objective:  To assess camouflage effects by concealment of postorthodontic white-spot lesions (WSLs) to sound adjacent enamel (SAE) achieved over 12 months with resin infiltration (Icon, DMG, Hamburg, Germany). Methods:   Twenty subjects (trial teeth nteeth = 111) who had received resin infiltration treatment of noncavitated postorthodontic WSLs were contacted for a 1-year follow-up assessment of CIE-L*a*b* colors (T12). Color and lightness (CIE-L*a*b*) data for WSLs and SAE were compared to baseline data assessed before infiltration (T0) and those assessed after 6 months (T6), using a spectrophotometer. The target parameter was the difference between the summarized color and lightness values (ΔEWSL/SAE). Intergroup (WSL, SAE) and intertime comparisons (T0 vs T6, T12) were performed using paired t-tests at a significance level of α = 5%. Results:  Nine subjects (trial teeth nteeth = 49; male/female ratio 5/4; age range 13–19 years) were available at T12. After the highly significant reduction of ΔEWSL/SAE discrepancies between T0 and T6, analysis of 12-month records revealed color and lightness discrepancy of WSL vs SAE that was significantly decreased compared with baseline, indicating an assimilation of WSL color to SAE appearance after infiltration, while an additional reduction of discrepancies between T6 and T12 was not significant. Conclusion:  As color and lightness characteristics of the Icon infiltrant as well as the esthetic camouflage effects achieved by WSL infiltration were not altered significantly or clinically relevant after 12 months, the method of resin infiltration can be recommended for an enduring esthetic improvement of postorthodontic WSL. (Angle Orthod. 2015;85:374–380.)

A Scanning Electron Microscopic Study of Early Enamel Caries Formed in Vivo beneath Orthodontic Bands

1996 ◽  
Vol 23 (1) ◽  
pp. 43-47 ◽  
Author(s):  
C. A. Melrose ◽  
J. Appleton ◽  
B. B. J. Lovius
Keyword(s):  
Enamel Surface ◽  
White Spot ◽  
Surface Zone ◽  
White Spot Lesions ◽  
Tissue Destruction ◽  
Electron Microscopic ◽  
Metal Wires ◽  
Caries Lesions ◽  
Scanning Electron

A clinical trial was conducted to investigate the development of caries lesions associated with fixed orthodontic appliance therapy. To introduce a cariogenic challenge on Sound buccal enamel surface in vivo, specially designed orthodontic bands were attached to premolars scheduled for extraction for orthodontic reasons. The bands were modified by having two metal wires (0·8 mm in diameter) welded to the inner surface of the band to produce a space for plaque accumulation similar to that occurring under loose orthodontic bands. The bands were cemented with a zinc phosphate cement (Tenet®) an left in situ for 4 weeks. Of 22 premolar teeth banded in eight different patients, eight showed definite white spot lesions, eight showed definite faint enamel opacities, and six showed no discernable lesions. Examination of definite white spot lesions by scanning electron microscopy revealed characteristic patterns of initial tissue destruction. Focal holes and an accentuation of the perikymata were observed affecting the enamel surface zone, an area previously considered to remain relatively intact during the development of a caries lesion. The superficial nature of the caries lesions observed and the rapidly of their formation is significant in the clinical management of decalcified areas forming beneath orthodontics bands.

scholarly journals Contact with Fluoride-Releasing Restorative Materials Can Arrest Simulated Approximal Caries Lesion

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Camila de Almeida Brandão Guglielmi ◽  
Ana Flávia Bissoto Calvo ◽  
Tamara Kerber Tedesco ◽  
Fausto Medeiros Mendes ◽  
Daniela Prócida Raggio
Keyword(s):  
Contact Point ◽  
White Spot ◽  
White Spot Lesion ◽  
White Spot Lesions ◽  
Double Blind ◽  
Restorative Materials ◽  
Ph Cycling ◽  
Approximal Surface ◽  
Mineral Loss

Previous studies have suggested that the presence of white-spot lesion is very probable when adjacent surface is affected by cavitated lesions. This study evaluated the potential of different fluoride-releasing restorative materials in arresting enamel white-spot lesions in approximal surface in contact with them,in vitro(I) andin situ(II). White-spot lesions were formed in 240 primary enamel specimens via pH-cycling. They were put in contact with cylindrical blocks of 6 materials (n=20): composite resin, 2 high-viscous glass ionomer cements (HVGIC), resin-modified GIC, resin-modified nanoionomer, and polyacid-modified resin. In both studies I and II, these settings were designed to simulate the contact point between the restoration and simulated approximal lesion. For study I, they were subjected to a new pH-cycling cariogenic challenge for 7 or 14 days (n=10). For study II, a randomized double-blindin situdesign was conducted in two phases (7/14 days) to promote cariogenic challenge. At the end of both studies, specimens were collected for mineral analysis by cross-sectional microhardness. Higher mineral loss was observed for lesions in contact with resin (p<0.001). HVGICs were the most efficient in preventing mineral loss, whereas other materials presented an intermediate behavior. It is concluded that fluoride-releasing materials can moderately reduce white-spot lesions progression, and HVGIC can arrest enamel lesion in approximal surface in contact with them.

scholarly journals Long-term follow-up of camouflage effects following resin infiltration of post orthodontic white-spot lesions in vivo

2018 ◽  
Vol 89 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Michael Knösel ◽  
Amely Eckstein ◽  
Hans-Joachim Helms
Keyword(s):  
Controlled Trial ◽  
White Spot ◽  
White Spot Lesions ◽  
Significance Level ◽  
Resin Infiltration ◽  
Long Term Follow Up ◽  
Age Range

ABSTRACT Objectives: To reassess the long-term camouflage effects of resin infiltration (Icon, DMG, Hamburg, Germany) of white spot lesions (WSL) and sound adjacent enamel (SAE) achieved in a previous trial. The null hypothesis was tested that there were no significantly different CIE-L*a*b*-ΔE-values between WSL and SAE areas of assessment after at least 24 months (T24) compared to those at baseline (T0). Materials and Methods: Of twenty subjects who received previous resin infiltration treatment of nteeth = 111 nonrestored, noncavitated postorthodontic WSL after multibracket treatment during a randomized controlled trial and were contacted 20 months after baseline, eight subjects (trial teeth nteeth = 40; m/f ratio 1/7; age range (mean; SD) 12–17 [15.25; 2.12] years); response rate: 40%) were available for follow-up after at least 24 months (T24). CIE-L*a*b* differences between summarized color and lightness values (ΔEWSL/SAE) of WSL and SAE were assessed using a spectrophotometer and compared to baseline data assessed prior to infiltration (T0), and those after 6 (T6), and 12 (T12) months using paired t tests at a significance level of α = 5%. Results: T24 assessments were performed after a mean 33.86 (SD: 8.64; Min: 24; Max: 45) months following T0. Mean (SD) ΔEWSL/SAE units of available teeth were 8.76 (5.33) at baseline; 5.5 (2.75) at T6; 5.2 (2.41) at T12; and 5.57 (2.6) at T24. Comparisons of T6, T12, and T24 with T0 yielded highly significant differences, whereas T6–T24 and T12–T24 differences were found to be not significant. Conclusions: Assimilation of infiltrated WSL to the color of adjacent enamel by resin infiltration is considered to be suitable for the long-term improvement in the esthetic appearance of postorthodontic WSL.

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