Secondary Caries Development in in situ Gaps next to Composite and Amalgam

2015 ◽  
Vol 49 (5) ◽  
pp. 557-563 ◽  
Author(s):  
Nicolien K. Kuper ◽  
Anelise F. Montagner ◽  
Françoise H. van de Sande ◽  
Ewald M. Bronkhorst ◽  
Niek J.M. Opdam ◽  
...  
Keyword(s):  
Composite Materials ◽  
Sucrose Solution ◽  
Secondary Caries ◽  
Mean Values ◽  
Before And After ◽  
Human Dentin ◽  
Caries Progression ◽  
Mineral Loss ◽  
Composite Samples

This in situ study investigated the secondary caries development in dentin in gaps next to composite and amalgam. For 21 days, 14 volunteers wore a modified occlusal splint containing human dentin samples with an average gap of 215 µm (SD = 55 µm) restored with three different materials: Filtek Supreme composite, Clearfil AP-X composite and Tytin amalgam. Eight times a day, the splint with samples was dipped in a 20% sucrose solution for 10 min. Before and after caries development, specimens were imaged with transversal wavelength independent microradiography, and lesion depth (LD) and mineral loss (ML) were calculated. The LD and ML of the three restoration materials were compared within patients using paired t tests (α = 5%). In total 38 composite samples (Filtek n = 19 and AP-X n = 19) and 19 amalgam samples could be used for data analysis. AP-X composite presented the highest mean values of LD and ML of the three restorative materials. Amalgam showed statistically significantly less ML (Δ = 452 µm × vol%) than the combined composite materials (p = 0.036). When comparing amalgam to the separate composite materials, only AP-X composite showed higher ML (Δ = 515 µm × vol%) than amalgam (p = 0.034). Analysis of LD showed the same trends, but these were not statistically significant. In conclusion, amalgam showed reduced secondary caries progression in dentin in gaps compared to composite materials tested in this in situ model.

Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ

2016 ◽  
Vol 50 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Richard J. Wierichs ◽  
Julian Lausch ◽  
Hendrik Meyer-Lueckel ◽  
Marcella Esteves-Oliveira
Keyword(s):  
Negative Control ◽  
Pronounced Change ◽  
Protocol Violation ◽  
Lesion Depth ◽  
Treatment Groups ◽  
Before And After ◽  
Double Blinded ◽  
Bovine Enamel ◽  
Mineral Loss

Objectives: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. Methods: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Results: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for ΔΔZ of the dentifrice with 0 ppm F, sound surfaces showed significantly higher ΔΔZ and ΔLD values compared with lowly and highly demineralized lesions (p < 0.05, t test). Conclusion: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth.

In situ Mineral Loss Inhibition by CO2 Laser and Fluoride

2006 ◽  
Vol 85 (7) ◽  
pp. 617-621 ◽  
Author(s):  
L.K.A. Rodrigues ◽  
M. Nobre dos Santos ◽  
J.D.B. Featherstone
Keyword(s):  
Laser Irradiation ◽  
Laser Treatment ◽  
Co2 Laser ◽  
Sucrose Solution ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Human Enamel ◽  
Fluoride Dentifrice ◽  
Mineral Loss

Laser and fluoride treatments have been shown to inhibit enamel demineralization in the laboratory. However, the intra-oral effects of this association have not been tested. This study assessed in situ the effect of a Transversely Excited Atmospheric CO2 laser (λ = 9.6 μm) and the use of pressure fluoridated dentifrice on enamel demineralization. During two 14-day phases, 17 volunteers wore palatal appliances containing human enamel slabs assigned to treatment groups, as follows: (1) non-fluoride dentifrice, (2) CO2 laser irradiation plus non-fluoride dentifrice, (3) fluoride dentifrice, and (4) CO2 laser irradiation plus fluoride dentifrice. A 20% sucrose solution was dripped onto the slabs 8 times per day. The specimens treated with laser and/or fluoridated dentifrice presented a significantly lower mineral loss when compared with those from the non-fluoride dentifrice group. The results suggested that CO2 laser treatment of enamel inhibits demineralization in the human mouth, being more effective when associated with fluoride.

scholarly journals Effect of Incorporation of Remineralizing Agents into Bleaching Gels on the Microhardness of Bovine Enamel in situ

2014 ◽  
Vol 15 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Carlos Rocha Gomes Torres ◽  
Alessandra Bühler Borges ◽  
Carolina Anne Guimarães ◽  
Eduardo Bresciani ◽  
Carolina Judica Ramos ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Human Saliva ◽  
Mean Values ◽  
Bleaching Procedure ◽  
Demineralized Enamel ◽  
Before And After ◽  
Bovine Enamel ◽  
Bleaching Gels ◽  
Intraoral Devices

ABSTRACT Aim This study evaluated the effect of adding calcium or fluoride to 35% hydrogen peroxide (HP) bleaching gel and the effect of human saliva on the microhardness of sound and demineralized enamel, using an in situ model. Materials and methods Cylindrical bovine enamel specimens (3 × 2 mm) were divided into two groups (n = 30): sound enamel (SE) and demineralized enamel (DE). Each group was divided into three subgroups, according to the bleaching gel: 35% HP; 35% HP + calcium; 35% HP + fluoride. After bleaching therapy, the specimens were fixed to intraoral devices worn by 10 volunteers for 7 days. Surface enamel microhardness (SMH) was measured before and after bleaching procedures, and after 1 and 7 days of saliva exposure. Data were analyzed by Repeated Measures ANOVA (5%). Results The variable time resulted in significant differences for SE and DE groups (p = 0.001). For SE, significantly lower SMH was detected for control at post-bleaching period in comparison to the baseline and after 7 days. For DE, the lowest mean values were obtained before bleaching, and the addition of calcium to the peroxide significantly increased enamel SMH. The exposure to human saliva resulted in increased SMH. Conclusion The addition of potential remineralizing agents into bleaching gels might play an important role in maintaining the microhardness of sound enamel and in inducing remineralization of artificially demineralized enamel right after bleaching, and the remineralizing action of human saliva might minimize the deleterious effects of bleaching gels on enamel. Clinical significance The incorporation of calcium into HP bleaching gel might be beneficial for the initial phases of the bleaching procedure. How to cite this article Borges AB, Guimarães CA, Bresciani E, Ramos CJ, Borges ALS, Torres CRG. Effect of Incorporation of Remineralizing Agents into Bleaching Gels on the Microhardness of Bovine Enamel in situ. J Contemp Dent Pract 2014;15(2):195-201.

scholarly journals Investigation of Unlubricated Sliding Wear Behaviours of In-Situ AlB2/Al Metal Matrix Composite

2011 ◽  
Vol 20 (4) ◽  
pp. 096369351102000 ◽  
Author(s):  
Ferit Ficici ◽  
Sakip Koksal ◽  
Ramazan Kayikci ◽  
Omer Savas
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Wear Behaviour ◽  
Test Results ◽  
Al Composite ◽  
The Matrix ◽  
Pin On Disk ◽  
Sliding Distance ◽  
Composite Samples

In this study, wear behaviour of AlB2/Al composite materials produced through in-situ method have been experimentally investigated. Four different composite materials that include 5wt.%, 10wt.%, 20wt.% and 30wt.% AlB2 reinforcement phase were tested using pin-on-disk arrangement. The effects of the rate of reinforcement on wear and friction behaviours have been investigated. Wear tests are carried out at 1.83, 3.40 and 4.71 m/s sliding speeds under 10, 20 and 40 N applied loads. The test results show that wear rate increases with the increase in applied load and sliding distance. Increasing the rate of reinforcement phase in the matrix has proportionally increased the wear resistance by 3% to 30%. Hence the greatest wear resistance has been observed with the composite materials having 30wt. % AlB2 reinforcement. Analysis of the worn surfaces of composite samples shows that abrasive and adhesive wear mechanisms are more effective.

scholarly journals Sensitivity of composite materials to ambient light and clinical working time

2012 ◽  
Vol 59 (4) ◽  
pp. 190-197
Author(s):  
Vesna Miletic ◽  
Tatjana Savic-Stankovic ◽  
Jovana Stasic
Keyword(s):  
Composite Materials ◽  
Hybrid Composites ◽  
Working Time ◽  
Lower Sensitivity ◽  
Ambient Light ◽  
Mean Values ◽  
Significance Level ◽  
Significant Difference ◽  
Before And After ◽  
The Difference

Introduction. The aim of this study was to determine sensitivity of composite materials to ambient light by a modified standard ISO 4049:2000 and clinical working time. Materials and Methods. The following materials were tested: nano-hybrid Herculite XRV Ultra (Kerr), micro-hybrid Herculite XRV (Kerr), Zmack (Zhermack), SuperCor (SpofaDental) and Valux Plus (3M ESPE). Five samples in each group were exposed to ambient light of 8000 lx, which comprised dental unit light and natural light. After 60 sec of exposure, each sample was visually examined for signs of inhomogeneity meaning that material did not pass the test. Clinical working time was studied by applying a custom-built, standardized indenter into composite specimens of about 2 mm thickness during the same exposure to ambient light. Completion of polymerization was tested by dissolving samples in ethanol and measuring the difference in thickness before and after the test. Results were statistically analyzed using ANOVA at the significance level of 0.05. Results. Only Herculite XRV Ultra passed the test of sensitivity to ambient light, while other materials showed signs of inhomogeneity. Herculite XRV Ultra showed significantly longer working time than other composites, the average was 250 sec (p<0.05). The mean values of working time for other materials ranged between 117-131 sec and there was no significant difference between them (p>0.05). Conclusion. Due to the lower sensitivity to ambient light and significantly longer clinical working time compared to micro-hybrid composites, Herculite XRV Ultra can be recommended for clinical procedures that require prolonged working time with material in plastic condition.

The Evaluation of Different Treatments of Incipient Caries Lesions: An in Situ Study of Progression Using Fluorescence-based Methods

2021 ◽  
Vol 46 (1) ◽  
pp. 87-99
Author(s):  
M Diniz ◽  
P Campos ◽  
M Souza ◽  
R Guaré ◽  
C Cardoso ◽  
...  
Keyword(s):  
Sucrose Solution ◽  
Adhesive System ◽  
Treatment Modalities ◽  
Treatment Protocols ◽  
Caries Lesion ◽  
Diagnodent Pen ◽  
Incipient Caries ◽  
Caries Lesions ◽  
Mineral Loss

Clinical Relevance Effective methods to control incipient caries lesions are needed. In this investigation, several methods provide encouraging results. SUMMARY This study aimed to evaluate in situ the inhibition of incipient caries lesion progression using different treatment protocols and to evaluate the effectiveness of fluorescence-based methods (DIAGNOdent, DIAGNOdent pen, and VistaProof fluorescence camera [FC]) in monitoring this process. The research was conducted in four phases: (1) at baseline, (2) after a first cariogenic challenge, (3) after treatment modalities, and (4) after a second cariogenic challenge. Sixteen volunteers used intraoral acrylic palatal appliances, each containing six enamel blocks (n=96). The cariogenic challenge was performed using a 20% sucrose solution over a 14-day period. The appliances were removed eight times a day and, upon removal, two drops of the solution were placed onto each enamel block. The enamel blocks were randomly assigned to three treatment groups: fluoride varnish ([FV] Duraphat; n=32), resin infiltrant ([RI] Icon; n=32), and adhesive system ([AS] Scotchbond; n=32). At the end of each phase, the surface microhardness (SMH) was measured, and two trained examiners evaluated the specimens using fluorescence-based methods. In addition, integrated mineral loss (ΔΔZ; vol%.min x μm) and lesion depth (ΔLD; μm) were evaluated using transverse microradiography. A two-way analysis of variance and a Tukey post hoc test were calculated (α=5%). Significant differences in SMH were observed according to the treatment, phases, and interaction of factors (p&lt;0.001). Treatment with FV resulted in significantly higher SMH values in phases 3 and 4 compared to RI and AS, with the last two treatments resulting in similar values (p&gt;0.05). The ΔΔZ value was similar for FV and AS but significantly higher for RI (p=0.016). ΔLD was not significantly different among the groups (p=0.126). Significant differences in the measurement of fluorescence for each fluorescence-based method were observed between each phase of the study (p&lt;0.05). It can be concluded that all treatments were effective in inhibiting the in situ progression of incipient lesions, although to different degrees, with minor mineral loss changes observed for the AS and FV. Besides, all fluorescence-based methods tested, except for that using the FC device, were effective in monitoring caries lesion progression.

Effectiveness of a Toothpaste with Low Fluoride Content Combined with Trimetaphosphate on Dental Biofilm and Enamel Demineralization in situ

2015 ◽  
Vol 49 (4) ◽  
pp. 394-400 ◽  
Author(s):  
Eliana M. Takeshita ◽  
Marcelle Danelon ◽  
Luciene P. Castro ◽  
Kikue T. Sassaki ◽  
Alberto C.B. Delbem
Keyword(s):  
Sucrose Solution ◽  
Blind Study ◽  
Double Blind Study ◽  
Oral Appliances ◽  
Double Blind ◽  
Sodium Trimetaphosphate ◽  
Dental Biofilm ◽  
Enamel Demineralization ◽  
Mineral Loss

Objective: The aim of the present study was to evaluate in situ whether a toothpaste with low fluoride associated with sodium trimetaphosphate (TMP) would provide similar effect to that of a 1,100 ppm F toothpaste. Design: This crossover double-blind study consisted of 4 phases (14 days each), during which 10 volunteers wore oral appliances containing 4 enamel bovine blocks. The cariogenic challenge was performed by the application of a 20% sucrose solution (6×/day). The toothpaste treatments (2×/day) were: placebo, 500 ppm F, 500 ppm F plus 1% TMP, and 1,100 ppm F. At the end, enamel mineral loss and biofilm composition were analyzed. Results: The toothpaste with 500 ppm F plus 1% TMP showed the lowest mineral loss (p < 0.05). Regarding the fluoride and calcium concentrations in the enamel and in the biofilm, there were no significant differences between 500 ppm F plus 1% TMP, and 1,100 ppm F toothpastes (p > 0.569), but they were significantly different when compared to toothpaste with 500 ppm F (p < 0.050). Conclusion: The addition of 1% TMP to a low-fluoride toothpaste reduces enamel demineralization in situ similar to a 1,100 ppm F toothpaste.

In situ Effect of Frequent Sucrose Exposure on Enamel Demineralization and on Plaque Composition after APF Application and F Dentifrice Use

2004 ◽  
Vol 83 (1) ◽  
pp. 71-75 ◽  
Author(s):  
A.F. Paes Leme ◽  
R. Dalcico ◽  
C.P.M. Tabchoury ◽  
A.A. Del Bel Cury ◽  
P.L. Rosalen ◽  
...  
Keyword(s):  
Sucrose Solution ◽  
Experimental Period ◽  
Mutans Streptococci ◽  
Plaque Composition ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Combination Of Methods ◽  
Bovine Enamel ◽  
Mineral Loss

Since the effect of the combination of methods of fluoride use on enamel demineralization and on plaque composition is not clearly established, this study examined the effect of the combination of acidulated phosphate fluoride (APF) application and F dentifrice on enamel demineralization and on plaque composition. In this crossover study, 16 volunteers, wearing a palatal appliance containing bovine enamel blocks, were subjected to 4 treatment groups: non-fluoridated dentifrice (PD), FD, APF+PD, and APF+FD. The APF was applied to the enamel before the 14-day experimental period. During the experimental period, test dentifrices were applied 3×/day, and a 20% sucrose solution was applied 4× and 8×/day by being dripped on the blocks. Although APF application was able either to increase F concentration in plaque or to reduce the % of mutans streptococci, its combination with F dentifrice use neither reduced enamel mineral loss nor changed any other measured plaque variable with respect to the FD group alone.

scholarly journals Effect of plaque accumulation and salivary factors on enamel demineralization and plaque composition in situ

2003 ◽  
Vol 17 (4) ◽  
pp. 326-331 ◽  
Author(s):  
Livia Maria Andaló Tenuta ◽  
José Eduardo de Oliveira Lima ◽  
Celso Luiz Cardoso ◽  
Cínthia Pereira Machado Tabchoury ◽  
Jaime Aparecido Cury
Keyword(s):  
Sucrose Solution ◽  
Salivary Secretion ◽  
Mutans Streptococci ◽  
Plaque Composition ◽  
Surface Microhardness ◽  
Enamel Demineralization ◽  
Caries Progression ◽  
Baseline Values ◽  
Bovine Enamel

This study evaluated the effect of some plaque and salivary factors on caries progression in situ. The salivary secretion rate, buffering capacity and mutans streptococci counts from 13 volunteers were determined. For three distinct periods of time, 4, 7 and 10 days, each of them wore a palatal appliance containing 4 bovine enamel blocks. They used a non-fluoridated dentifrice during the experiment and a 20% sucrose solution was dripped onto the blocks 10 times a day. Mutans streptococci (MS), calcium (Ca), and insoluble polysaccharide (IP) were quantified in the dental plaque formed on the enamel blocks, after each period. Enamel demineralization was assessed by surface microhardness, and the percentage of surface microhardness change (%SMC) in relation to the baseline values was calculated. Enamel demineralization occurred after each period of plaque accumulation (p < 0.05), and the %SMC increased with time (from 13.8 to 48.3%). The concentrations of Ca and IP in plaque were not statistically different among the experimental times, but significant correlations were found between these concentrations and %SMC. Neither the salivary factors assessed initially nor mutans streptococci in plaque presented statistically significant correlations to %SMC. The results suggest that enamel demineralization is time-dependent and is more related to the composition of the biofilm formed than to the salivary factors studied.

Effects on Demineralization of Enamel by Fluoridated Sucrose: A Pilot Study in an in Situ Caries Model

1995 ◽  
Vol 9 (1) ◽  
pp. 9-13 ◽  
Author(s):  
P. Carlsson ◽  
B. Angmar-Mansson ◽  
I.-M. Redmo-Emanuelsson ◽  
K. Anderssén
Keyword(s):  
Pilot Study ◽  
Sucrose Solution ◽  
Sugar Content ◽  
Dry Weight ◽  
Thin Sections ◽  
Human Enamel ◽  
Caries Model ◽  
Weight One ◽  
Mineral Loss

Blocks of human enamel, placed in removable partial dentures, were allowed to acquire natural plaque for seven days and were exposed extra-orally to a cariogenic challenge by repeated periods in a fluoride-sucrose solution. As a control, enamel blocks were exposed extra-orally to a sucrose solution. After two weeks of cariogenic challenge, the blocks were examined for mineral loss by quantitative microradiography on thin sections of the enamel. The results from six subjects showed that no significant effect on demineralization could be detected by the addition of fluoride corresponding to fluoride/sugar content of 1 mg/kg, 5 mg/kg, or 10 mg/kg (dry weight). One subject did not develop lesions at all, either with fluoride-sucrose or with sucrose exposure alone.

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