Murat Selim Botsali

Conventional and high intensity halogen light effects on water sorption and microhardness of orthodontic adhesives.

OBJECTIVE To test the null hypothesis that when the equivalent total light energy is irradiated to three orthodontic adhesive resins, there is no difference between the microhardness and water sorption values regardless of the curing light sources. MATERIALS AND METHODS Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light-Bond, Transbond XT) and two light intensities (quartz tungsten halogen [QTH] and high intensity quartz tungsten halogen [HQTH]). One half of each of the 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH light source, and the other half was polymerized for 10 seconds by a HQTH light source. Water sorption was determined and Vickers hardness was established with three measurements per sample at the top, center, and bottom. Statistical analysis was performed using two-way analysis of variance (ANOVA) with multiple comparisons (Tukey-HSD). RESULTS Statistically significant differences were found among all adhesives for water sorption and hardness values cured with QTH and HQTH. The HQTH curing unit resulted in higher values than did the QTH. The highest water sorption values were observed for Kurasper F cured with HQTH and the lowest value was observed for Transbond XT cured with QTH. For microhardness Light-Bond cured with HQTH produced the highest values, and Transbond XT cured with QTH produced the lowest. CONCLUSIONS When the equivalent total light energy is irradiated to three orthodontic adhesive resins, there are significant differences between the microhardness and water sorption values cured with the QTH and HQTH light source. The null hypothesis is rejected.

Conventional and High-Intensity Halogen Light Effects on Polymerization Shrinkage of Orthodontic Adhesives

The objectives of this study were to compare the polymerization shrinkage of three orthodontic adhesives. In addition we wanted to determine the effectiveness of the high-intensity quartz tungsten halogen (HQTH) in curing orthodontic adhesives on polymerization shrinkage with that of the quartz tungsten halogen (QTH). A total of 120 glass ring molds were prepared using a low-speed saw. The internal surface of the glass rings were roughened and etched. Adhesive pastes were placed into the glass molds, which were sandwiched between two glass slides. Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light Bond, and Transbond XT) and two light intensities. One half of each 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH (Hilux 350), and the other half was polymerized for 10 seconds by a HQTH (Optilux 501). The volumetric polymerization shrinkage for each system was measured through the specific density method modified by Puckett and Smith. Statistical analysis was performed using two-way analysis of variance for intergroup comparisons. The HQTH-curing unit resulted in a more polymerization shrinkage than did the QTH for all investigated adhesives. However, no statistically significant differences were found. The highest shrinkage was observed for Light Bond cured with HQTH (1.59 +/- 0.82%), and the lowest value was observed for Transbond XT cured with QTH (1.23 +/- 0.60%). There are no significant differences in polymerization shrinkage of the three investigated orthodontic adhesives when polymerized with a QTH or a HQTH.

Residual monomer release from orthodontic adhesives cured with different light sources

Abstract Introduction: The aim of this study was to evaluate the residual monomer release from orthodontic adhesives cured with light-emitting diode (LED) and halogen light sources. Methods: Seven hundred and twenty stainless steel brackets were divided into 3 groups according to the adhesive system used (Transbond XT light-cure adhesive [TXT], Transbond LR capsule [LR], and Light Bond light-cure adhesive paste [LB]), and each group was divided into 2 subgroups according to light-curing procedure (LED or halogen). Brackets were bonded with adhesives onto tooth buccal surfaces and polymerized. Each specimen contained 24 brackets that simulated the oral environment (n = 5). The specimens were immersed in a 75% ethanol/water solution at 37 °C for 10 min, 1 h, 1 d, 7 d, 14 d, and 30 d, respectively. Eluted monomers (Bis-GMA, UDMA, and TEGDMA) were detected using HPLC. Results: There was residual monomer release at all time periods, and the highest amount of release was observed cumulatively on the 30th day. The cumulative Bis-GMA released from adhesives was not different (p > 0.05). The cumulative TEGDMA released from adhesives was statistically different (p < 0.05). There was no statistical difference between QTH and LED light-curing units for each adhesive (p > 0.05). Conclusions: The release of residual monomers stays at a high level for a long time after polymerization. The total leaching of residual monomers from the Light Bond light-cure sealant resin plus Light Bond light-cure adhesive paste was higher than that of other materials for both curing units. Different curing units (LED or QTH) did not affect the monomer release from the orthodontic adhesives.

Treatment of post-orthodontic white spot lesions with CPP-ACP paste: A three year follow up study

To determine the efficacy of topical applications of 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste in reverting white spot lesions (WSLs) after fixed orthodontic treatment. Forty one participants were randomly assigned to either the test group (CPP-ACP) or the control group (only fluoride toothpaste). All patients used regular fluoride-containing toothpaste. CPPACP paste or fluoridated toothpaste was applied on to tooth surfaces with WSLs twice a day during 36-month after de-bonding. The labial/buccal surfaces of teeth were assessed by use of DIAGNOdent pen (DD), Gorelick Index and ICDAS II criteria at baseline (T1) and 36-month (T2) follow-up visits. The total counts of Streptococcus mutans and Lactobacillus were obtained at T1 and T2. DMFT, DMFS, stimulated flow rate and buffer capacity were calculated in two appointments. Daily usage of CPP-ACP paste was not better than normal care for improving the appearance of WSLs after 36 months.

Effect of new innovative restorative carbomised glass cement on intrapulpal temperature rise: an ex-vivo study

This study aimed to evaluate the temperature changes that occurred in the pulp chamber when using GCP Glass Carbomer Fill (GCP) and two different resin-modified glass-ionomer (RGI) restorative materials at different dentin thicknesses. A standardized Class I occlusal cavity with 1 mm or 2 mm dentin thickness was prepared in the extracted human molar teeth. RGI and GCP fills were placed in the cavities and cured with two different light-curing units. This study included a total of 120 samples, with 20 samples in each group. The pulp microcirculation method was used for measuring the intrapulpal temperature changes. Statistical analysis was performed using the two-way ANOVA and Tukey HSD multiple comparison tests. Statistically significant differences were observed between 1 mm and 2 mm dentin thicknesses (p < 0.001). The GCP groups (both 1 mm and 2 mm dentin thicknesses) exhibited higher temperatures than the other groups (p < 0.001), and Fuji II LC and Photac Fil Quick Aplicap showed similar values (p > 0.05). The highest temperature changes were observed with 1 mm dentin thickness. While RGI materials in both dentin thicknesses did not cause temperature changes that were harmful to the pulp, GCP CarboLED LCU caused the highest intrapulpal temperature rise, and these values were borderline harmful to the dental pulp.

Evaluation of HEMA released from four different adhesive systems by HPLC

Purpose This study evaluated the elution of 2-hydroxyethyl methacrylate (HEMA) from 4 different adhesives, using high-performance liquid chromatography (HPLC). Materials and Methods The adhesives were applied on a bovine dentin surface and polymerized using an LED curing unit (n=5). After polymerization, specimens were stored in 75% ethanol solution (6 mL). Residual HEMA that was eluted from adhesives (after 10 minutes, 1 hour, 24 hours, 7 days and 30 days) was analyzed using HPLC. Statistical analyses were performed using 1-way ANOVA, Tukey HSD test and paired 2-sample t-test. Results There were statistically significant differences among adhesive systems for the cumulative released HEMA and among the time periods (p<0.05). Clearfil SE Bond showed the highest amount of HEMA released, while Easy Bond showed the lowest. Among the time periods, the highest eluted HEMA value was detected in 10 minutes for all adhesives, and elution continued for up to 30 days. Conclusions The HEMA eluted from adhesives was in different amounts, and the elution continued for a long time. The amount of eluted HEMA from adhesives used in this study was not viewed as critical for toxic reactions in biological tissues.

Effect of different surface treatments on the shear and microtensile bond strength of resin-modified glass ionomer cement to dentin

Abstract Objective. The aim of this study was to evaluate the effect of different surface treatments on the microtensile bond strength (μTBS) and shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) to dentin. Materials and methods. Fifty-two extracted human molars were flattened to obtain dentin surfaces. For SBS assessment 40 teeth were divided into four groups according to their surface treatments (acid etching, Er:YAG laser QSP mode, Er:YAG laser MSP mode and control-SiC) (n = 10). A plastic cylinder was placed over the differently treated dentin surfaces and RMGIC was placed into the rings and polymerized. Twelve teeth were used for the μTBS test. The treated dentin surfaces described above were restored with 4 mm high RMGIC and light cured; then, the specimens were sectioned into serial sticks (n = 15) and μTBS and SBS were tested for failure in a testing machine with a 1 mm/min crosshead speed. The data were analyzed by one-way ANOVA and Tukey HSD tests (α = 0.05). Results. Acid etching showed significantly higher SBS than the other groups (p < 0.05). Er:YAG QSP and MSP-treated groups showed higher SBS values than the control group, but the difference was not statistically significant (p > 0.05). Er:YAG MSP showed the highest μTBS value followed by acid etching, whereas the control group exhibited the lowest value (p < 0.05) and the differences between the control group and Er:YAG QSP were not significant (p > 0.05). Conclusions. The application of Er:YAG MSP mode and acid etching to dentin can be used for improving the bond strength of RMGIC.

Effect of increased exposure times on amount of residual monomer released from single-step self-etch adhesives

Background The aim of this study was to evaluate the effect of increased exposure times on the amount of residual Bis-GMA, TEGDMA, HEMA and UDMA released from single-step self-etch adhesive systems. Methods Two adhesive systems were used. The adhesives were applied to bovine dentin surface according to the manufacturers instructions and were polymerized using an LED curing unit for 10, 20 and 40 seconds (n = 5). After polymerization, the specimens were stored in 75% ethanol-water solution (6 mL). Residual monomers (Bis-GMA, TEGDMA, UDMA and HEMA) that were eluted from the adhesives (after 10 minutes, 1 hour, 1 day, 7 days and 30 days) were analyzed by high-performance liquid chromatography (HPLC). The data were analyzed using 1-way analysis of variance and Tukey HSD tests. Results Among the time periods, the highest amount of released residual monomers from adhesives was observed in the 10th minute. There were statistically significant differences regarding released Bis-GMA, UDMA, HEMA and TEGDMA between the adhesive systems (p<0.05). There were no significant differences among the 10, 20 and 40 second polymerization times according to their effect on residual monomer release from adhesives (p>0.05). Conclusions Increasing the polymerization time did not have an effect on residual monomer release from single-step self-etch adhesives.

KALSİYUM SİLİKA İÇERİKLİ PULPA KAPLAMA MATERYALİNİN IŞIK KAYNAĞININ ÜÇ FARKLI MODU İLE POLİMERİZASYONU ESNASINDA OLUŞAN ISI ARTIŞININ İNCELENMESİ

Pulp damage may occur because of the temperature rise during polymerization of light-cured dental materials. Aim: The purpose of this study was to evaluate three different curing modes of a light emitting diode (LED) on the temperature rise in the pulp chamber during polymerization of a light-cured resin-modified calcium silicate filled pulp-capping material. Material and Method: A straight-cut was made to the occlusal surface of an extracted molar ensuring 1 mm dentin thickness over the pulp. Pulpal circulation was simulated by water cycling through the pulp chamber with a defined flow pressure to simulate the clinical case. Temperature rise was measured during the light curing of capping material (Theracal, Bisco Inc.,USA). Three modes of light curing unit (Planmeca Lumion,Mectron,Italy) were used to polymerizate the material; fast (FP), slow rise (SRP) and soft (SP). Thermal changes were measured by a data-logger. The data were statistically analyzed by one-way ANOVA. Results: ANOVA test showed that pulp chamber temperature changes were influenced by the mode of light source. All groups showed significant differences between each other (P<0.05). The intrapulpal temperature changes induced by different modes were: (7.19±0.44°C) for FP, (6.62±0.34°C) for SRP, (6.10±0.37°C) for SP. Conclusion: Following conclusions were drawn; The intrapulpal temperature changes induced by various light modes were: FP, SRP and SP in descending order. All curing modes of light curing unit showed significant differences between each other. Light curing of the TheraCal with different polymerization modes of the same light unit resulted in more than 5.5°C increase in the pulp chamber

Polymerization shrinkage of six different fissure sealants

Objectives: The objective of this study was to evaluate and compare the polymerization shrinkage of six proprietary pit and fissure sealants (Helioseal F, Fissurit FX, Smartseal & loc F, Dyract Seal, Clinpro TM Sealant, Teethmate F-1). Materials and Methods: A total of 120 glass ring molds (8.5 mm in inner diameter and 2 mm in height) were prepared after which the internal surface of the molds were etched with hydrofluoric acid for 5 min. The test materials (n = 20/group) were placed into the molds and thereafter sandwiched between two glass slides. All groups were polymerized for 20 s using a high-intensity quartz tungsten halogen (HQTH) light unit (Optilux 501). The volumetric polymerization shrinkage for each pits and fissure sealant was measured using the specific density method modified by Puckett and Smith. All data were analyzed statistically using one-way analysis of variance and Tukey honest significant difference (HSD) test at P < 0.05. Results: A ranking for the shrinkage values were obtained as follows: Teethmate F-1 (7.40 ± 1.17%) > Clinpro TM Sealant (6.60 ± 1.54%) > Dyract Seal (5.38 ± 1.30%) > Smartseal & loc F (5.06 ± 1.22%) > Fissurit FX (4.30 ± 1.15%) > Helioseal F (3.30 ± 0.69%). Clinpro TM Sealant and Teethmate F-1 displayed the highest shrinkage values (P < 0.05). The lowest shrinkage values were obtained with Helioseal F (3.30 ± 0.69%) and Fissurit FX (4.30 ± 1.15%) (P < 0.05). Conclusion: Within the experimental conditions of the present study, sealant materials containing higher concentrations of fillers displayed lower polymerization shrinkage values.