Effect of a novel commercial potassium-oxalate containing tooth-desensitizing mouthrinse on the microhardness of resin composite restorative materials with different monomer compositions.

BACKGROUND: The effects of mouthrinses on dental resin composites have been investigated extensively. However, there is little information available regarding the effects of 'newly developed mouthrinse' formulations on the microhardness of different monomer based composite systems. Therefore, the aim of this study was to investigate the effect of a novel potassium-oxalate containing desensitizing mouthrinse on the microhardness of different monomer based composite materials. MATERIAL AND METHODS: A hundred and twenty specimens (6mm in diameter and 2mm in height) were prepared for composite resin groups (methacrylate based, DX-511 monomer based and silorane monomer based) and for storage solution groups (artificial saliva and potassium oxalate-containing tooth-desensitizing mouthrinse). After allowing post-polimerization the baseline Knoop microhardness measurements for all specimens were recorded. The specimens were stored in 20 mL mouthwash and artificial saliva for 12 hours at 37ºC. The post-immersion microhardness values of all specimens were also recorded. Data were subjected to ANOVA/Scheffe's test at a significance level of 0.05. The intra group (pre and post immersion values) comparison of the mean microhardness values of the specimens was done using Wilcoxon signed rank test. RESULTS: The microhardness of the silorane based composite was not affected significantly (p>0.05). The hardness values of the DX-511 monomer based composite and the methacrylate based composite exhibited a slight but not significant microhardness change compared to the baseline values (p>0.05). CONCLUSIONS: Studies reported that the effect of mouthrinses on microhardness changes of composite resins may be material dependent, and the hardness change susceptibility of a restorative material may be attributed to its resin matrix or filler type. However, dental monomers as well as the oral care products have an ever-evolving technology and future studies should consider newer products. Potassium oxalate containing mouthrinses, especially alcohol-free ones, may be used safely with dental composites with newly developed low-shrink monomer compositions. Key words:Microhardness, monomers, mouthrinses, potassium-oxalate.

Influence of activated bleaching on various adhesive restorative systems.

STATEMENT OF THE PROBLEM: When adhesive restorations are used in combination with bleaching in clinical applications, it is generally recommended to wait for a period of time between the two procedures. However, it is not clear if a time interval is necessary between applying the bleaching treatments and the silorane-based restorative system. PURPOSE: The purpose of this in vitro study was to determine if activated bleaching affects the bond strength of silorane-based restorative, a newly developed restorative that uses a polymerization system that has been reported to be insensitive to oxygen. METHODS: A gel consisting of 38% hydrogen peroxide was applied to ground labial enamel surfaces and activated using a diode laser to bleach the teeth. Then, without waiting for any period of time, four different restorative materials were applied to the bleached enamel surfaces, and these sets were compared with nonbleached control samples. The shear bond strength of the restorative systems to enamel was tested, and data was evaluated using two-way analysis of variance and Tukey HSD tests. RESULTS: Significant differences (p<0.05) in shear bond strengths were found among bleached and nonbleached enamel surfaces. CONCLUSION: It may be more beneficial to allow a time interval of 2 to 3 weeks between activated hydrogen peroxide bleaching and applying silorane-based composite restoratives or methacrylate-based composites than just applying restorative agents immediately after bleaching. However, further studies are needed to examine the structural effects of activated hydrogen peroxide on enamel. CLINICAL SIGNIFICANCE: A time interval should be allowed between the application of silorane-based or methacrylate-based restorations and activated hydrogen peroxide bleaching systems.

The effect of dentin hypersensitivity treatments on the shear bond strength to dentin of a composite material.

This study sought to evaluate the influence of a dentin desensitizer and ozone application on the bond strength to dentin of a composite resin material. The dentin desensitizing agent and ozone treatment were applied on the cervical dentin surfaces of extracted, caries-free, erupted third molars. Dentin surfaces that received no treatment were used as control samples. A dentin bonding agent was applied according to the manufacturer's instructions and an adhesion test was performed according to ISO/TS 11405. Statistical analysis showed no significant influence of the different hypersensitivity treatments on shear bond strength to dentin (ANOVA and Tukey's tests, p > 0.05). Within the limitations of this in vitro study, it appears that the short-term use of dentin hypersensitivity treatments like ozone and dentin desensitizers containing gluteraldehyde do not further affect the shear bond strength to dentin of subsequent composite resin restorations.

Prevalence of oral abnormalities in a Turkish newborn population.

OBJECTIVE: There are a few studies that describe the oral findings in newborn children in various populations but none conducted for a Turkish population. Hence, this study determined the prevalence of intraoral findings in a group of newborns and examined the correlation among these findings with the mother's systemic and gestational medical complications, cigarette consumption during pregnancy and consanguinity between the parents. METHODS: 2,021 full-term, newborn children were examined. Oral cysts, ankyloglossia, attached upper midline frenum and other medical diagnoses at birth were investigated. Medical information for each child and parent was recorded via standard questionnaire. Obtained data was analysed using the Pearson Chi-Square test (P≤0.05). RESULTS: The most common findings were of oral inclusion cysts situated palatally. CONCLUSIONS: There was a statistically significant relationship between the presence of oral inclusion cysts with the congenital diabetes and also insulin treatment and cigarette consumption during pregnancy. Moreover, a significant relationship was found between the presence of oral inclusion cysts and gestational diabetes and with the presence of consanguinity between the parents (P=0.004).

Low-level laser therapy of dentin hypersensitivity: a short-term clinical trial.

The aim of this study was to evaluate low-level laser therapy in cervical dentin hypersensitivity. A randomized controlled clinical trial was conducted with a total of 64 teeth. Dentin desensitizer and diode laser were applied on the cervical dentin surfaces. Distilled water and placebo laser was used as the placebo groups. The irradiance used was 4 J/cm(2) per treatment site. The baseline measurement of hypersensitivity was made by using visual analog scale (VAS). Twenty-four hours and 7 days after the application of desensitizer, diode laser and placebo groups, a new VAS analysis was conducted for the patients' sensitivity level. The mean pain scores of placebo groups were significantly higher than the desensitizer's and diode laser's mean scores (ANOVA, p < 0.05). The VAS analysis revealed a significant decrease in dentin hypersensitivity in 7 days with the use of the desensitizer and low-level laser therapy and no statistically significant difference was observed between these two treatments (p > 0.05). Although low-level laser and glutaraldehyde containing desensitizer present distinct modes of action, experimental agents caused a significant reduction of dentin hypersensitivity without showing secondary effects, not irritating the pulp or causing pain, not discoloring or staining the teeth, and not irritating the soft tissues at least for a period of 1 week with no drawbacks regarding handling and/or ease of application. Low-level laser therapy and desensitizer application had displayed similar effectiveness in reducing moderate dentin hypersensitivity.

Shear bond strength to enamel after power bleaching activated by different sources.

The purpose of the present study was to evaluate enamel bond strength of a composite resin material after hydrogen peroxide bleaching, activated by a diode laser (LaserSmile), an ozone device (HealOzone), a light-emitting diode (BT Cool whitening system), and a quartz-Plus. Fifty extracted caries-free permanent incisors were used in this study. Thirty-eight percent hydrogen peroxidegel was applied to sound, flattened labial enamel surfaces and activated by different sources. Enamel surfaces that had received no treatment were used as control samples. Bonding agent was applied according to the manufacturer's instructions and the adhesion test was performed according to ISO/TS 11405. Statistical analysis showed significant influence of the different activation technique of hydrogen peroxide on shear bond strength to enamel (ANOVA, LSD, P < 0.05). The data in this vitro explorative study suggest the activation of hydrogen peroxide by different sources may further affect the shear bond strength of subsequent composite resin restoration to enamel. Within the limitations of this in vitro study, further studies examining the structural changes of activated hydrogen peroxide-treated enamel are needed. Due to the different activation methods; duration of light irradiation effects, longer time periods may be needed before application of adhesive restorations to enamel, compared with non-activated bleaching.

Influence of a dentin desensitizer and a red-wavelength diode laser application on bond strength of composite to dentin in vitro.

OBJECTIVE: To evaluate the influence of a dentin desensitizer (Smartprotect Desensitizer) and a diode laser (Scorpion Dental Optima) application on the bond strength of a composite resin material to dentin. BACKGROUND DATA: Dentin-hypersensitivity treatments may influence the bond strength to dentin. MATERIALS AND METHODS: Thirty extracted caries-free, erupted permanent third molars were used in this study. Dentin-desensitizing agent and diode laser were applied onto the cervical dentin surfaces. Dentin surfaces that had received no treatment were used as control samples. Dentin bonding agent was applied according to the manufacturer's instructions, and the adhesion test was performed according to ISO TR 11405. RESULTS: The following shear-bond strengths were obtained (mean values and standard deviations in MPa): control group, 11.73 ± 3.85 MPa; desensitizer-applied group, 11.45 ± 3.33 MPa; and diode laser-applied group, 10.52 ± 2.52 MPa. Statistical analysis showed no significant influence of the variable, different hypersensitivity treatments on shear-bond strength to dentin [analysis of variance (ANOVA), Tukey HSD test, p > 0.05). The data in this in vitro explorative study suggest that the short-term use of diode lasers and dentin desensitizers may not further affect the shear-bond strength of subsequent composite resin restoration to dentin. CONCLUSIONS: Within the limitations of this in vitro study, further studies are needed examining the structural changes of treated dentin and its adhesion characteristics to adhesive restorative materials.

Primary ciliary dyskinesia: Kartagener syndrome with central giant cell granuloma. A case report.

This paper describes a clinical case of both giant cell granuloma and Kartagener syndrome in a 15-year-old male patient, with emphasis on the radiographic aspects of this extremely unusual pathology. To our knowledge, the presence of these 2 rare clinical conditions in the same patient has not been previously reported.

Low-level laser therapy effects in traumatized permanent teeth with extrusive luxation in an orthodontic patient.

The aim of this case report was to present and evaluate the effect of low-level laser therapy on traumatized permanent teeth with extrusive luxation in an orthodontic patient. The treatment and follow-up evaluation of two orally luxated maxillary permanent central incisors in a 19-year-old man is described. Detailed anamnesis was taken, and extraoral, intraoral, radiographic examinations and electrical and thermal pulpal tests were performed to determine the type of the luxation and the further treatment protocol. Teeth were splinted with composite resin, and antibiotic therapy was prescribed. Low-level laser therapy was applied for 25 sessions. No root canal treatment was applied to the teeth. Continuation of the orthodontic treatment was restarted after 6 months. No sign of clinical or radiographic pathology was detected after 2 years from the end of the treatment. Teeth were identified healthy and sound without any root canal intervention. Treatments with low-level laser applications may be evaluated as noninvasive alternative treatment options in comparison with endodontic treatment for teeth with extrusive luxation more than 2 mm, especially for those who have orthodontic treatment needs.

Influence of experimental provisional cements containing zeolite, bone hydroxyapatite and linoleic Acid on bond strength of composite to dentin in vitro.

PURPOSE: to evaluate the dentin bond strength of a composite resin material after the removal of two experimental cements containing zeolite, bone hydroxyapatite and linoleic acid, and one conventional glass-ionomer cement intended as provisional cements. MATERIALS AND METHODS: forty extracted caries-free, erupted permanent third molars were used. Experimental provisional cements containing zeolite and bone hydroxyapatite (BHA) and one conventional glass-ionomer cement (GIC) were placed on the dentin surfaces and covered with tinfoil. Cement-covered dentin surfaces were stored in distilled water at 37°C ± 2°C for seven days. After this period, temporary cements were mechanically removed, dentin surfaces were rinsed in distilled water and dried with an air syringe before adhesive application. Dentin bonding agent was applied according to the manufacturer's instructions and the adhesion test was performed according to ISO TR 11405. RESULTS: the following shear bond strengths for the composite material were obtained: no treatment applied (control, group 4): 17.30 ± 1.37 MPa; provisional cement containing BHA (group 2): 15.03 ± 3.44 MPa; GIC (group 3): 14.13 ± 2.85 MPa; provisional cement containing zeolite (group 1): 11.29 ± 2.71 MPa. The difference between groups 1 and 4 the control group was significant, where as the statistical analysis showed no significant difference between the control and BHA groups (ANOVA, Tukey's, p > 0.05). CONCLUSION: in clinical applications where the previous application of provisional cements is necessary, material choice may influence the bond strength of the subsequent composite resin restoration.

Adhesion to primary and permanent dentin and a simple model approach.

OBJECTIVES: First to compare different dentin bonding agents' shear bond strength to primary and permanent dentin. Secondly to compare the fracture failure modes and making an attempt to develop a statistical model that could be helpful in predicting them. METHODS: Extracted human primary and permanent molars were used as substrates (dentin). The shear bond strength of composite to substrate was measured and fracture surfaces were evaluated visually and with stereomicroscope. Using the data obtained, a statistical model was built in order to predict the failure modes. RESULTS: Higher bond strength values were obtained for permanent dentin. Total-etch adhesives displayed higher shear bond strength values than the self-etch adhesive. Adhesive failures were more frequently seen in primary dentin. Self-etch adhesive system displayed more adhesive failures. Prepared model confirmed the negative relationship between shear bond strength and the probability of observing adhesive failure. CONCLUSIONS: There should be an application protocol for the usage of dentin bonding agents in primary dentin. Further development of statistical and fuzzy models for failure modes can be supportive alternatives for microscopic evaluations and also be helpful in understanding and eliminating the factors which are responsible for the formation of adhesive failures and for achieving clinically more successful adhesive restorations.

Usage of fiber-reinforced resin instruments in interproximal surfaces.

OBJECTIVES: The aim of this study was to investigate the effects of fiber-reinforced resin burs on the surface roughness of a nanofilled composite. METHODS: Average surface roughness values (Ra, mum) were measured using a surface profilometer and surface textures after finishing procedures were evaluated using a scanning electron microscope (SEM). Thirty cylindrical specimens were prepared using sectional teflon molds. A nanofilled composite was chosen. After the preparation specimens were divided into three subgroups randomly. After profilometric measurements, representative samples of the mentioned finishing procedures were selected and SEM analyses were carried out. RESULTS: Mylar strip group was statistically different from the other two groups (P<.05). The smoothest surfaces occurred when composite resin samples were light cured against the strips. On the other hand there was no statistical difference between fiber-reinforced resin burs and Sof-Lex discs (P>.05). For fiber-reinforced resin burs scratches and pitting which may be due to plucking of the filler particles during finishing were observed on the surface topography of the composite resin material. On the other hand, for the Sof-Lex discs although scratches were noticed on the surface topography, no pitting was observed. CONCLUSIONS: Fiber-reinforced resin burs can be preferred for the grinding of composite surplus in interproximal surfaces, where the use of Sof-Lex discs can be harmful to soft tissues.

Linear regression modeling to compare fluoride release profiles of various restorative materials.

OBJECTIVES: The aim of this study was to compare the released fluoride profiles of various restorative materials by using linear regression analysis. METHODS: Specimens were prepared using a cylindrical Teflon mold with a height of 2 mm and a radius of 8 mm. After being prepared, specimens were immediately placed into artificial saliva which was replaced at various times during 6 weeks. These released intrinsic fluoride amounts were measured by using an ion selective electrode. Then, data obtained cumulatively were statistically analyzed, and the released profiles were compared. RESULTS: It was observed that the materials released fluoride at different levels of concentration and the largest fluoride release was obtained from the conventional glass ionomer cement. This was followed by resin modified glass ionomer cement, polyacid modified composite resin, and fluoride releasing composite resin, respectively. Although the released fluoride amounts of the materials were different, their release profiles were found to be similar in that the release was initially fast and then it became steady as time passed. SIGNIFICANCE: The statistical modeling of the release profiles helps to compare the fluoride release behavior of materials and also to predict fluoride release amounts for the future. In literature, for these purposes, separate nonlinear statistical models have extensively been utilized. However, the single linear statistical modeling approach has numerous advantages such as providing estimators having good statistical properties, exact results, precise inference and simplicity in calculation. Therefore, this study was conducted to introduce the use of single linear regression modeling to compare release profiles statistically.