Treatment of developmental defects of enamel.

Developmental defects of enamel are encountered daily in our dental practice. The management of enamel hypomineralized lesions may be challenging, especially as esthetic concern around the young population is increasing. Resin infiltration, a new technique firstly proposed to halt caries progression in the posterior segment, showed a strong positive esthetic effect in the treatment of developmental defects with different etiologies. Future in-vivo studies are needed to evaluate the longterm color stability, in order to provide a strong clinical recommendation.

The Effect of Resin Infiltration on the Progression of Proximal Caries Lesions: A Randomized Clinical Trial.

OBJECTIVE: The aim of this clinical trial was to assess the effect of resin infiltration on the progression of proximal caries lesions. SUBJECTS AND METHODS: Forty-one patients, aged between 15 and 33 years, with 2 or more non-cavitated proximal caries lesions were included. In 41 of the adolescent and young adults, 45 pairs of proximal lesions with radiological extension into the inner and outer half of the enamel, or into the outer third of the dentin, were randomly allocated to the test groups (resin infiltration application + fluoridated toothpaste and flossing use) or to the control group (fluoridated toothpaste and flossing use). Standardized geometrically aligned digital bitewing radiographs were obtained using individual biting holders. The radiographic progression of the lesions was assessed after 1 year by digital-subtraction radiography. The McNemar test was used for statistical analysis. RESULTS: In the test group 1/45 of the lesions (2.2%) and in the control group 9/45 of the lesions (20%) showed progression. The caries progression rate of the control group was significantly higher than that of the test group (p < 0.05). CONCLUSIONS: Resin infiltration of proximal caries lesions is effective in reducing progression of the lesion.

Dental resin as controlled release layer for the development of an innovative long-acting intra-oral delivery system.

The objective of the present study was to develop a novel long-acting intra-oral delivery system (LIDS) to overcome the frequent administration by the nonparenteral route with Huperzine A (HupA) as a model drug. HupA-LIDS was prepared using a magnetic drug delivery with dental resin as release controlling layer for long-term release of HupA. The factors that influenced the drug release comprised of the type and amount of pore formers, the speed of shaker, resin layer weight and drug loading. These factors were evaluated and optimized. The in-vitro release studies showed that the system was able to deliver HupA in an approximately zero-order kinetic. The SEM study showed that the multiple orifices on the surface of a resin layer formed due to presence of pore formers, which contributed to the HupA release. The pharmacokinetic study in rabbits demonstrated the HupA-LIDS could be released in vivo for more than 8 days with prolonged Tmax and significantly reduced Cmax in comparison with commercial tablets. This study provided some pioneering ideas for developing intra-oral extended release drug delivery system using dental resin as release controlling materials. The optimized HupA-LIDS can make excellent sustained release and have the potential for the long-acting product in the therapy of Alzheimer's disease.

Single-Arm, Open-Label, Multicenter Study to Evaluate the Safety and Performance of Dura Sealant Patch in Reducing Cerebrospinal Fluid Leakage Following Elective Cranial Surgery: The ENCASE Trial Study Protocol.

BACKGROUND: Cerebrospinal fluid (CSF) leakage is one of the most common neurosurgical complications, occurring in 4% to 32% of surgical cases, with a higher incidence in complicated skull base surgery, intradural spine surgery, and the surgery of the posterior fossa. Our group developed a Dural Sealant Patch (DSP) for watertight dural closure after cranial surgery. OBJECTIVE: To clinically study for the first time the safety and performance of the DSP as a means of reducing CSF leakage in patients undergoing elective cranial intradural surgery with a dural closure procedure. METHODS: We will conduct an open-label, single-arm, multicenter study with a 360 d (12 mo) follow-up. A total of 40 patients will be enrolled at 3 sites. The primary endpoint is a combination of occurrences of one of the following events: postoperative percutaneous CSF leakage, intraoperative leakage at 20 cm H2O, or postoperative wound infection. The secondary endpoints are pseudomeningocele and thickness of dura + DSP. EXPECTED OUTCOMES: Not more than 3 patients will meet the primary endpoint suggesting safety and efficacy. DISCUSSION: As a next step, a randomized controlled trial against the best current practice will follow to evaluate if DSP reduces CSF leakage while its safety is noninferior.

Accelerated aging effects on color, microhardness and microstructure of ICON resin infiltration.

OBJECTIVE: Infiltration resins provide an ideal treatment alternative for white spot lesions on teeth. The icon infiltrant has been widely used as a dental material for a few years, but there are some studies on the in vitro accelerated aging process and the change of hardness and microstructure on this material. The innovation of this work is to aim at investigating characteristics associated with this infiltrant resin and comparing the Icon infiltrant with universal Filtek Z350 and flowable Filtek Z350 resins when exposed to artificial accelerated aging. MATERIALS AND METHODS: Materials were prepared as disc-shaped specimens sized to 12 mm × 2.2 mm and were aged through exposure to 150 kJ/m2 in an artificial accelerated aging machine. Two-time points, 24 h after aging and 96 h after aging, were selected for evaluation in the following trials. The morphology was observed using a scanning electron microscopy. The standard CIEL*a*b* color system was employed for color measurements. Microhardness of all specimens was analyzed by a Knoop indenter. Chemical components were examined by Fourier transform infrared spectroscopy. RESULTS: Compared with universal Z350 and flowable Z350, the ICON infiltrant resin presented a uniform, slightly scratched surface before and after accelerated aging. The 24 h artificial accelerated aging of the three investigated materials resulted in acceptable color alterations, a ΔE* range of 2.52±0.63 for universal Z350, 2.43±0.59 for flowable Z350 and 3.31±0.32 for ICON. After 96 h aging, significant color changes were noted for universal Z350 (7.51±0.63) and ICON (4.70±0.69). The ICON infiltrant displayed reduced microhardness when compared to universal Z350 and flowable Z350. The absorption peaks of the chemical bonds were significantly altered after the accelerated aging process. CONCLUSIONS: Composed in a triethylene glycol dimethacrylate (TEGDMA) monomer-based network, the color stability and microhardness of the infiltrant resin provided suitable material for treating white spot lesions (WSLs), yet presented susceptibility under accelerated aging. Thus, osmotic resin therapy has strict limitations to be most effective.

Novel Antibacterial Resin-Based Filling Material Containing Nanoparticles for the Potential One-Step Treatment of Caries.

The aim of this work was to study the application of resin filling containing nanomaterials for the potential treatment of caries. Zinc nanoparticles (ZnO@NP, 50 nm) were chosen for their antimicrobial capacity against aerobic bacteria, and here, they have proved to be bactericidal against anaerobic bacterial strains (Streptococcus mutans, Streptococcus mitis, and Lactobacillus spp.). Potential mechanism of action is proposed based on microbiological assays and seems to be independent of oxidative stress because the nanoparticles are effective in microaerophilic conditions. The loading of nanoparticles on the demineralized dental surface and their infiltration power were significantly improved when ZnO@NP were carried by the resin. Overall, this material seems to have a high potential to become a one-step treatment for caries lesions.

Influence of infiltrant application time on the reduction of opaqueness of proximal enamel caries.

INTRODUCTION: Infiltrant resins were developed to hamper carious lesion progression and mask the whitish appearance of first evidence of caries. OBJECTIVE: This study aimed at testing the hypothesis that a long application time of resin infiltrant in proximal enamel caries improves esthetic outcome compared to the commercially recommended time. MATERIALS AND METHODS: Twenty teeth with uncavitated inactive proximal white enamel caries lesions (selected by two calibrated examiners; inter-examiner κ = 0.87) were divided into two groups (experimental and control group; n = 10) that agreed regarding lesion surface area. Lesions were infiltrated following the protocol recommended by the manufacturer (two applications, 3 min application first and another 1 min application later; control) and by the protocol tested in this study (one application of 30 min; experimental). Enamel opaqueness (esthetic outcome) was measured by a calibrated examiner (intra-class coefficient of 0.9) before and after infiltration using fluorescence microscopy. RESULTS: Reduction of enamel opaqueness was significantly higher in the experimental group (40.0% ± 18.5%) than in the control group (18.6% ± 14.9%) (P = 0.0105, one-tailed t-test; Hedge's g of 1.28, 95% confidence interval of 0.43/2.13, and power of 86%). CONCLUSIONS: It can be concluded that the application time of 30 min provides a greater reduction in opaqueness of proximal enamel lesion compared to the application time recommended by the manufacturer. The high effect size could stimulate patients to comply with the treatment time.

Treatment of various degrees of white spot lesions using resin infiltration-in vitro study.

BACKGROUND: This study was conducted to evaluate the efficiency of resin infiltration to improve the color of white spot lesions (WSLs) and to estimate the effect of different numbers of etching and resin infiltrant applications on the color change of WSLs with various depths. Ninety-six sound extracted premolars were subjected to acid attack inducing different depths of WSLs. Using a DIAGNOdent, teeth were divided into four main groups according to the depth of the WSLs: shallow enamel, deep enamel, shallow dentine, and deep dentine without cavitation. Then each of the main groups was subdivided into four groups: six teeth each with different protocols of resin infiltration as follows: 1 etching + 1 infiltrant application (EA), 1 etching + 2 infiltrant applications (EAA), 2 etchings + 1 infiltrant application (EEA), 2 etchings + 2 infiltrant applications (EEAA). Spectrophotometric analysis was measured at baseline (T0), after inducing the WSLs (T1), and following resin infiltration application (T2) for each group. RESULTS: In shallow enamel, EA produced the least mean color difference (1.62 ± 0.85), with high significant difference (P < 0.001), when compared with the clinically detectable threshold (ΔE = 3.7). While in deep enamel, EAA showed the least mean color change (1.95 ± 0.4), with P < 0.001 when compared with the critical value. Also, in shallow dentine, the least mean change was noticed with EAA (3.0 ± 0.45), with P < 0.001 when compared with the clinical color detection threshold. Furthermore, in deep dentine, EAA had the least mean difference (3.76 ± 0.6) but with no significant difference, when compared with the clinically detectable threshold. CONCLUSIONS: As the WSL got deeper, the color of the lesion became more clinically visible. In shallow enamel, the best treatment option was one etching with one resin infiltrant application. For deep enamel and shallow dentine, one etching with two applications of infiltrant gave the best lesion masking. In deep dentine, it is advisable to perform one etching with two infiltration steps, taking in consideration that all deep dentine lesions without cavitation were partially masked, remained clinically detectable, and might require more invasive restorative procedures.

Effect of resin infiltration on the color and microhardness of bleached white(-)spot lesions in bovine enamel (an in vitro study).

This study would appear to give little steer as to which of the many approaches most effectively manage white spot lesions.

Development of a novel resin-based dental material with dual biocidal modes and sustained release of Ag+ ions based on photocurable core-shell AgBr/cationic polymer nanocomposites.

Research on the incorporation of cutting-edge nano-antibacterial agent for designing dental materials with potent and long-lasting antibacterial property is demanding and provoking work. In this study, a novel resin-based dental material containing photocurable core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) was designed and developed. The shell of polymerizable cationic polymer not only provided non-releasing antibacterial capability for dental resins, but also had the potential to polymerize with other methacrylate monomers and prevented nanoparticles from aggregating in the resin matrix. As a result, incorporation of AgBr/BHPVP nanocomposites did not adversely affect the flexural strength and modulus but greatly increased the Vicker's hardness of resin disks. By continuing to release Ag+ ions without the impact of anaerobic environment, resins containing AgBr/BHPVP nanoparticles are particularly suitable to combat anaerobic cariogenic bacteria. By reason of the combined bactericidal effect of the contact-killing cationic polymers and the releasing-killing Ag+ ions, AgBr/BHPVP-containing resin disks had potent bactericidal activity against S. mutans. The long-lasting antibacterial activity was also achieved through the sustained release of Ag+ ions due to the core-shell structure of the nanocomposites. The results of macrophage cytotoxicity showed that the cell viability of dental resins loading less than 1.0 wt% AgBr/BHPVP was close to that of neat resins. The AgBr/BHPVP-containing dental resin with dual bactericidal capability and long term antimicrobial effect is a promising material aimed at preventing second caries and prolonging the longevity of resin composite restorations.

Streptococcus mutans adherence and biofilm formation on experimental composites containing dicalcium phosphate dihydrate nanoparticles.

This study aimed at evaluating bacterial adhesion and biofilm formation on resin-based composites (RBC) including dicalcium phosphate dihydrate nanoparticles (nDCPD). METHODS: Specimens were prepared from experimental RBCs with BisGMA/TEGDMA resin matrix including 20 vol% of either nDCPD (nDCPD-RBC), TEGDMA-functionalized nDPCD (F-nDCPD-RBC) or silanized silica (SiO2-RBC). Neat resin blend (control-Resin), conventional nanohybrid RBC (control-RBC) and human enamel were used for reference. Characterization of the specimens included surface roughness (SR), surface free energy (SFE), chemical surface composition (EDS, XPS), and buffering ability of a pH = 4.00 solution. Streptococcus mutans adherence was assessed after 2 h; biofilm formation was simulated for 48 h using a bioreactor. Adherent, viable biomass was determined using tetrazolium salt assay (MTT). RESULTS: nDCPD-RBC yielded highest roughness and showed higher polar and lower disperse component to total SFE. EDS and XPS indicated higher amounts of calcium and phosphate on the surface of nDCPD-RBC than on F-nDCPD-RBC. nDCPD buffered the acidic solution to 5.74, while functionalization almost prevented buffering (pH = 4.26). F-nDCPD-RBC reduced adherence and biofilm formation in comparison to nDCPD-RBC. Regardless of functionalization, biofilm formation on nDCPD-containing RBCs was not significantly different from SiO2-RBC. Control-Resin, control-RBC, and enamel surfaces showed similar adherence values as F-nDCPD-RBC, but lower biofilm formation compared to both nDCPD-containing RBCs. In conclusion, the incorporation of nDCPD did not minimize S. mutans adherence and biofilm formation as a function of the materials´ surface properties. However, results observed for the buffering capacity indicated that optimized formulations of biomimetic RBCs may be useful for modulating their interaction with microorganisms.

Infiltración de resina como tratamiento mínimamente invasivo de lesiones de caries dental incipiente / Resin infiltration as a minimally invasive treatment for incipient dental caries lesions

La mínima intervención en cariología ha sido definida como la filosofía de cuidados estomatológicos que se encarga del tratamiento de la primera aparición, la detección temprana y el tratamiento de la caries dental. Una de las técnicas para el tratamiento temprano y detención de lesiones incipientes es la infiltración de resina. El objetivo es mostrar la utilidad de las resinas fluidas para la infiltración de un primer y segundo molar inferior permanentes con una lesión incipiente de caries dental. Se trata de un paciente masculino de 17 años de edad sin antecedentes patológicos, que acude a consulta estomatológica. En hemiarcada inferior izquierda se observaron manchas en forma de punto de color marrón oscuro cerca de la fosita central y en la estría vestibular del 36 y 37 respectivamente, que no presentaban más de 1 mm de profundidad. Se diagnosticaron lesiones de caries dental incipiente y se decidió realizar una infiltración con resina compuesta de baja viscosidad o fluida en consulta única. El uso de resinas compuestas fluidas es beneficioso en la infiltración de lesiones cariosas incipientes de esmalte, pues evita su propagación y sella las brechas de esmalte afectado. Es una técnica de mínima intervención en cariología, que propicia una solución inmediata para estos procesos y mayor sencillez para la solución de la enfermedad caries dental al equilibrar las expectativas estéticas y de mantenimiento de las estructuras dentarias sanas(AU)

Minimal intervention in cariology has been defined as the philosophy of dental care that deals with the treatment of the first occurrence, early detection and treatment of dental caries. Resin infiltration is one of the techniques used for early treatment and arrest of incipient lesions. The objective is to show the usefulness of fluid resins for infiltration of a first and second lower permanent molar with an incipient dental caries lesion. A 17 year-old male patient with a healthy history attended dental consultation with dark brown point spots on the lower left hemiarch near the central pit and on the vestibular groove of 36 and 37, respectively, of not more than 1 mm in depth. Incipient dental caries lesions were diagnosed and it was decided to perform infiltration of low viscosity composite or fluid resin in a single visit. Use of fluid composite resins is suitable for infiltration of incipient enamel caries lesions, for it prevents spread and seals the gaps in the affected enamel. It is a minimal intervention technique in cariology providing immediate solution to these processes as well as greater ease to solve dental caries disease balancing esthetic expectations with expectations related to the maintenance of healthy dental structures(AU)

Improvement of side-effects and treatment on the experimental colitis in mice of a resin microcapsule-loading hydrocortisone sodium succinate.

CONTEXT: Extensive or long-time use of corticosteroids often causes many toxic side-effects. The ion exchange resins and the coating material, Eudragit, can be used in combination to form a new oral delivery system to deliver corticosteroids. OBJECTIVES: The resin microcapsule (DRM) composed by Amberlite 717 and Eudragit S100 was used to target hydrocortisone (HC) to the colon in order to improve its treatment effect on ulcerative colitis (UC) and reduce its toxic side-effects. METHODS: Hydrocortisone sodium succinate (HSS) was sequentially encapsulated in Amberlite 717 and Eudragit S100 to prepare the HSS-loaded resin microcapsule (HSS-DRM). The scanning electron microscopy (SEM) was employed to investigate the morphology and structure of HSS-DRM. The in vitro release and in vivo studies of pharmacokinetics and intestinal drug residues in rat were used to study the colon-targeting of HSS-DRM. The mouse induced by 2,4,6-trinitrobenzenesulfonic acid was used to study the treatment of HSS-DRM on experimental colitis. RESULTS: SEM study showed good morphology and structure of HSS-DRM. In the in vitro release study, > 80% of HSS was released in the colon environment (pH 7.4). The in vivo studies showed good colon-targeting of HSS-DRM (Tmax = 0.97 h, Cmax = 118.28 µg/mL of HSS; Tmax = 2.16 h, Cmax = 64.47 µg/mL of HSS-DRM). Moreover, the HSS-DRM could reduce adverse reactions induced by HSS and had good therapeutic effects on the experimental colitis. CONCLUSIONS: The resin microcapsule system has good colon-targeting and can be used in the development of colon-targeting preparations.

Técnicas para reduzir os efeitos da contração de polimerização das resinas compostas fotoativadas / Techniques for reducing the effects of polymerization shrinkage of composites photoactivated resins

Introdução: uma complicação inerente a todas as resinas compostas é o stress gerado pela contração de polimerização. As resinas compostas da atualidade, após a polimerização, perdem entre 2% a 3% de todo o seu volume. Essa perda pode acarretar em alterações fortemente comprometedoras a nível micro e macroscópico. Objetivo: abordar a importância do uso de técnicas e manobras clínicas, que visam diminuir a contração de polimerização das resinas compostas, reduzindo seus efeitos na cavidade, para que se tenha um procedimento restaurador com elevado índice de sucesso clínico e boa aceitação pelos pacientes. Material e Métodos: foi realizada uma revisão da literatura por meio de uma busca bibliográfica nas seguintes bases de pesquisa online: PUBMED/MEDLINE, LILACS, BBO e SCIENCE DIRECT, através do rastreio de artigos relevantes publicados entre o período de 2000 a 2015. Resultados: comparando as formas de ativação dos compósitos, os compósitos fotopolimerizáveis possuem um menor escoamento e maior stress de contração se comparados a compósitos com ativação química, isso se dá devido à fotoativação que se destaca por ser uma reação rápida quando comparada a outros métodos, não dispondo de tempo para a resina se acomodar na cavidade e ter uma boa interação com o sistema adesivo previamente aplicado, levando a grande parte dos problemas clínicos das restaurações. Conclusão: questionamentos sobre os efeitos da contração de polimerização, ainda não foram completamente elucidados no meio científico, por isso algumas técnicas como a escolha de fotopolimerizadores a LED, manutenção da fase pré gel, manutenção do Fator C e técnica de inserção incremental, podem ser usadas para minimizar os efeitos dessa contração nas restaurações feitas com resina, afim de reduzir insucessos como, sensibilidade pós operatória, infiltração marginal e riscos de agressão pulpar levando a uma maior longevidade dos procedimentos restauradores com materiais resinosos. (AU)

Introduction: a complication inherent in all composite resins is the stress generated by the polymerization contraction. The present composite resins, after polymerization, lose between 2% and 3% of their entire volume. This loss can lead to strongly compromising micro and macroscopic changes. Objective: to address the importance of using technical and clinical maneuvers, which aim to reduce polymerization shrinkage of composite resins, reducing its effects in the cavity, in order to have a restorative procedure with high clinical success rate and good patient acceptance. Material and Methods: a review of the literature through a literature search in the following search online databases was performed: PubMed/MEDLINE, LILACS, BBO and SCIENCE DIRECT, through the screening of relevant articles published between 2000 to 2015. Results: comparing both activation of composites, the dental composites have a lower flow and higher stress of contraction compared to composites with chemical activation, this is the due to photoactivation that stands out for being a quick reaction when compared to other methods, not providing time for the resin to settle in well and have a good interaction with the previously applied adhesive system, leading to much of the clinical problems of restorations. Conclusion: questions about the effects of polymerization shrinkage have not been fully elucidated in the scientific community, so some techniques such as the choice of curing lights to LED, the pre gel phase maintenance, maintenance of Factor C and incremental insertion technique can It is used to minimize the effects of this contraction in restorations made with resin in order to reduce failures as post-operative sensitivity, microleakage and pulp assault risks leading to increased longevity of restorative procedures with resinous materials. (AU)

Randomised Clinical Trial on Resin Infiltration and Fluoride Varnish vs Fluoride Varnish Treatment Only of Smooth-surface Early Caries Lesions in Deciduous Teeth.

PURPOSE: To clinically evaluate the effectiveness of resin infiltration in conjunction with fluoride varnish treatment vs fluoride varnish treatment alone on facial smooth-surface caries lesions in deciduous teeth. MATERIALS AND METHODS: This randomised clinical trial was conducted in 419 children aged 18-71 months with at least two active smooth-surface caries lesions in deciduous teeth (ICDAS II score 2). Eighty-one participants met the inclusion criteria and were allocated to one of the two treatment groups: resin infiltration and fluoride varnish (RI+FV) (n = 41) and fluoride varnish only (FV) (n = 40). The prevalence of treated white spot lesions (WSL) was scored. Fluoride varnish was applied in both groups every 3 months for a year. RESULTS: The mean baseline age of children was 3.8 ± 1.3 years. The effectiveness of resin infiltration measured as the percentage of children who did not present any progression of the treated lesions amounted to 43.1%. After one year, 92.1% of the infiltrated lesions (RI+FV) and 70.6% of the FV lesions had not progressed (p < 0.001). CONCLUSION: Resin infiltration in conjunction with fluoride varnish treatment of early facial smooth-surface caries lesions in deciduous teeth is superior to fluoride varnish treatment alone for reducing lesion progression.

Success Rate of Treatments Provided for Early Childhood Caries under General Anesthesia: A Retrospective Cohort Study.

PURPOSE: The purpose of this study was to assess the success rate of various treatments provided under general anesthesia for early childhood caries (ECC) over three-year follow-up period. METHODS: ECC children no older than 72 months at the time of dental surgery, who had completed a three-year follow-up, were included. The success rate of every treatment was evaluated. The longevity of each treatment and significant factors associated with failures were assessed. RESULTS: A total of 818 children (55.8 percent were males with a mean age of 46.2±13.4 months old) were included. Of these, 32.9 percent had restored teeth that required further treatment during the three-year follow-up. Amalgam restorations and stainless steel crowns (SSCs) showed significantly longer survival than composite restorations in all types of restorations (P<.05). The survival rate of both indirect pulp capping and pulpotomies were the same (P=0.234), and they were significantly higher than that for pulpectomies (P=0.001, P=0.039, respectively). The lower lingual holding arch (LLHA) had a significantly lower survival rate than other space maintainers (P<0.05). CONCLUSIONS: SSCs and amalgam restorations were clinically more successful and had better survival times than composite restorations. The survival rate for the LLHA was low compared to other space maintainers.

Bonding brackets on white spot lesions pretreated by means of two methods.

OBJECTIVE: The aim of this study was to evaluate the shear bond strength (SBS) of brackets bonded to demineralized enamel pretreated with low viscosity Icon Infiltrant resin (DMG) and glass ionomer cement (Clinpro XT Varnish, 3M Unitek) with and without aging. METHODS: A total of 75 bovine enamel specimens were allocated into five groups (n = 15). Group 1 was the control group in which the enamel surface was not demineralized. In the other four groups, the surfaces were submitted to cariogenic challenge and white spot lesions were treated. Groups 2 and 3 were treated with Icon Infiltrant resin; Groups 4 and 5, with Clinpro XT Varnish. After treatment, Groups 3 and 5 were artificially aged. Brackets were bonded with Transbond XT adhesive system and SBS was evaluated by means of a universal testing machine. Statistical analysis was performed by one-way analysis of variance followed by Tukey post-hoc test. RESULTS: All groups tested presented shear bond strengths similar to or higher than the control group. Specimens of Group 4 had significantly higher shear bond strength values (p < 0.05) than the others. CONCLUSION: Pretreatment of white spot lesions, with or without aging, did not decrease the SBS of brackets.

Evaluation of resin infiltration using quantitative light-induced fluorescence technology.

OBJECTIVES: To determine whether quantitative light-induced fluorescence (QLF) technology can be used to classify the colour of teeth specimens before and after resin infiltration (RI) treatment, and calculate the correlation between the ΔF value and colour difference (ΔE) in fluorescence images of the specimens obtained using a QLF-digital (QLF-D) device. METHODS: Sixty sound bovine permanent teeth specimens were immersed in demineralized solution. Two exposed windows were formed in each specimen, and RI treatment was applied to one of them. The ΔE values were obtained for the differences between a sound tooth surface (SS), an early dental caries surface (ECS) and an ECS treated with RI (RS) in white-light and fluorescence images obtained using QLF-D, respectively. The ΔF value was obtained from fluorescence images using dedicated software for QLF-D. The mean differences between the ΔE values obtained from the white-light and fluorescence images were analyzed by paired t-test. Pearson correlation analysis and Bland-Altman plots were applied to the differences between the ΔF value for ECS (ΔFSS-ECS) and the ΔE value between SS and ECS (ΔESS-ECS), and between the ΔF value for RS (ΔFSS-RS) and the ΔE value between SS and RS (ΔESS-RS) in fluorescence images. RESULTS: The ΔE values obtained from fluorescence images were three times higher than the ΔE values obtained from white-light images (p<0.001). Significant correlations were confirmed between ΔESS-ECS and ΔFSS-ECS (r=-0.492, p<0.001) and between ΔESS-RS and ΔFSS-RS (r=-0.661, p<0.001). CONCLUSION: QLF technology can be used to confirm the presence of RI in teeth.

Bonding brackets on white spot lesions pretreated by means of two methods

Abstract Objective: The aim of this study was to evaluate the shear bond strength (SBS) of brackets bonded to demineralized enamel pretreated with low viscosity Icon Infiltrant resin (DMG) and glass ionomer cement (Clinpro XT Varnish, 3M Unitek) with and without aging. Methods: A total of 75 bovine enamel specimens were allocated into five groups (n = 15). Group 1 was the control group in which the enamel surface was not demineralized. In the other four groups, the surfaces were submitted to cariogenic challenge and white spot lesions were treated. Groups 2 and 3 were treated with Icon Infiltrant resin; Groups 4 and 5, with Clinpro XT Varnish. After treatment, Groups 3 and 5 were artificially aged. Brackets were bonded with Transbond XT adhesive system and SBS was evaluated by means of a universal testing machine. Statistical analysis was performed by one-way analysis of variance followed by Tukey post-hoc test. Results: All groups tested presented shear bond strengths similar to or higher than the control group. Specimens of Group 4 had significantly higher shear bond strength values (p < 0.05) than the others. Conclusion: Pretreatment of white spot lesions, with or without aging, did not decrease the SBS of brackets.

resumo Introdução: o objetivo do presente estudo foi avaliar a resistência ao cisalhamento de braquetes colados ao esmalte desmineralizado e pré-tratado com uma resina infiltrante de baixa viscosidade (Icon, DMG) ou com um selante ionomérico (Clinpro XT Varnish, 3M Unitek), com e sem envelhecimento. Métodos: setenta e cinco (75) amostras de esmalte bovino foram divididas em cinco grupos (n = 15). No Grupo 1 (controle), a superfície do esmalte não foi desmineralizada. Nos outros quatro grupos, as superfícies foram submetidas ao desafio cariogênico e as lesões de manchas brancas foram tratadas previamente à colagem de braquetes. Nos Grupos 2 e 3, as lesões foram tratadas com a resina Icon; nos Grupos 4 e 5, com o selante Clinpro XT Varnish. Após o tratamento, os Grupos 3 e 5 foram envelhecidos artificialmente. Os braquetes foram colados, sobre as lesões tratadas, utilizando-se o sistema adesivo Transbond XT, e a resistência ao cisalhamento foi avaliada em máquina universal de ensaios. A análise estatística foi realizada por meio da análise de variância e, posteriormente, pelo teste post-hoc de Turkey. Resultados: todos os grupos testados apresentaram resistência ao cisalhamento semelhante ou maior do que o grupo controle. As amostras do Grupo 4 apresentaram valores de resistência ao cisalhamento significativamente maiores (p < 0,05) do que as dos demais grupos. Conclusão: o tratamento das manchas brancas, com ou sem envelhecimento, não diminuiu a resistência ao cisalhamento dos braquetes.

Development of a taste-masked oral suspension of clindamycin HCl using ion exchange resin Amberlite IRP 69 for use in pediatrics.

PURPOSE: The purpose of this study is to develop an oral suspension of clindamycin resin complex for the potential use in pediatrics. METHODS: Several types of Ion exchange resins were screened for their binding efficiency with clindamycin. In order to develop a suspension formulation, several thickening agents, surfactants, sweeting, and flavoring agents were evaluated for their influence on the release of clindamycin from resinate. Rheological studies were also conducted to select the optimum amounts of the suspending agents. The release profiles of clindamycin in SGF and SIF were also evaluated from freshly prepared suspension and from suspension formulation after storage for 1 month at 25 °C and 40 °C. Clindamycin bitterness threshold was determined based on volunteers' evaluation, and taste evaluation was conducted in 12 adult volunteers who evaluated the taste of the optimized suspension against clindamycin solution. RESULTS: Among all resins tested, Amberlite IRP 69 showed the highest binding efficiency to clindamycin. Several excipients were selected into the suspension formulation based on no or minimum influence on the release of clindamycin from the resinate complex. Moreover, xanthan gum was selected as the optimal suspending agent for the suspension. Clindamycin release profiles in SGF or SIF showed 90% release within 30 min from freshly prepared sample. Clindamycin exhibited good stability profiles at 25 °C and 40 °C over 1 month storage. The mean bitterness threshold of clindamycin was 12.5 µg/ml, and taste evaluation study in adults showed sustainable taste improvement for suspension over clindamycin solution. CONCLUSION: Clindamycin/resin complexation has shown to be an efficient method to mask the taste of clindamycin and was developed into a suspension formulation that can be used in pediatrics.