TPH Spectrum Research Articles

Comparison of Marginal Integrity of Class-1 Restorations With Spectrum Tph-3 Versus Nexcomp In Mandibular Molars - A Quasi-Experimental Study

Objective: To compare the marginal integrity of Class-1 restorations with Spectrum TPH-3 vs Nexcomp in mandibular molars. Study Design: Quasi-experimental study. Place and Duration of Study: Operative Dentistry Department of Armed Forces Institute of Dentistry (AFID), Rawalpindi, Pakistan, from Sep 2020 to May 2021. Methodology: A total of 60 candidates were enrolled and allocated randomly to one of two groups, A and B. Group-A received spectrum TPH3 and Group-B received Nexcomp composite. Patients were followed up after 2 and 6 months for evaluation of marginal fractures with the help of loupes, probes, mouth mirrors and bitewing radiographs. Result: The rate of marginal fractures in Nexcomp were greater (27% at 2 months and 30% at 6 months) as compared to Spectrum TPH3 (73% at 2 months and at 77% 6 months) yielding a statistically significant difference between the two groups (p value= 0.004 and 0.001). Conclusion: Spectrum TPH gives a better quality of posterior restoration as compared to Nexcomp, contributing positively towards better quality of oral health for patient.

Effect of Instrument Lubricant on Mechanical Properties of Restorative Composite.

Using a wetting resin or adhesive system as an instrument lubricant when placing composite layers is commonly practiced to improve handling. This study investigated whether instrument lubricants affected strength, stiffness, or hardness. Composite beams (TPH Spectra) were fabricated using a stainless steel mold (25×2.5×2 mm) in two steps, where the second half (12.5 mm) was added and cured against a cured first half (n=15). The composite surface at the open end of the first half was smoothed using an instrument lubricated with wetting resin (Ultradent) or universal adhesive (ScotchBond Universal), enough to prevent sticking, or without lubrication. An additional beam of each group was characterized using scanning electron microscopy. Monolithic specimens were also fabricated. After 24 hour storage (37°C, 100% humidity), the beams' flexural strength and stiffness were determined by four-point bending. Vickers surface hardness was measured on 24-hour composite samples in 2 mm deep acrylic cavities, cured after the surface was smoothed with the two instrument lubricants or no lubricant (n=10). Hardness was remeasured after finishing with a series of contouring and polishing discs. Data were statistically analyzed using ANOVA followed by Student-Newman-Keuls post hoc test at 0.05 significance level. There were significant differences (p<0.001) in flexural strength and stiffness among groups. While strength and stiffness were not affected by using a wetting resin as instrument lubricant, use of a universal adhesive increased strength and stiffness significantly, achieving monolithic values. Scanning electron micrographs showed less porosities at the interface when using instrument lubricants. Surface hardness was significantly reduced in groups in which instrument lubricants were used, but finishing/polishing restored original hardness (p<0.001). Lubricating an instrument with a wetting agent did not adversely affect physical or surface properties, provided the surface was finished and polished. If a universal adhesive was used as lubricant, the strength and stiffness of a layered composite could be increased, reaching monolithic values.

Fluorescence intensity of composite resin for direct veneer removal using a fluorescence-aided identification technique.

This laboratory study evaluated the influence of the fluorescence intensity of composite resins on additional tooth wear and the presence of restorative material in different dental thirds during the retreatment of direct veneers. The crown dimensions of 60 bovine incisors were reduced to 10 × 8 mm. The teeth were classified according to the fluorescence intensity of the composites: low (LOW) (TPH Spectra), medium (MED) (Opallis), and high (HIGH) (Essentia) groups. The teeth were divided according to the removal methods: conventional (CON) and fluorescence-aided identification technique (FIT). The specimens were scanned (T0), received veneer preparation, and scanned again (T1). After restorations, the composites were removed and the teeth were scanned (T2). Measurement assessments between T1 and T2 were performed to determine additional wear, presence of residual areas, and the average between additional wear and the presence of residual areas. Kruskal Wallis, Mann-Whitney, Friedman, 2-way ANOVA, and post-Tukey tests were performed (α < 0.05). The comparison of composite resins indicated a smaller area of additional wear and greater residue presence in the HIGH group than the LOW group for both techniques in the cervical third. Regarding removal methods, the FIT produced greater additional wear than the CON method for the LOW and MED groups in the middle and cervical thirds. The incisal third exhibited greater additional wear than the other thirds. Composite resins with high fluorescence intensity removed using FIT had less tooth wear. The incisal third was the most affected area for direct veneer removal procedures. A FIT has been proposed for composite resin removal; however, the different fluorescence intensities of composite resins can influence tooth wear caused during this procedure.

Assessment of the Color Variation of the Various Nanocomposites: An Invitro Study

Aim: The goal of this study was to see how accelerated artificial ageing (AAA) affected the colour of composite resins used in dentistry. Materials and Methods: We piloted an invitro study with 2 nanofilled Premise and Filtek Z350 and microfilled Spectrum TPH. A total of 90 specimens equally distributed for the three composites were selected. The color measurements were obtained with a Spectrophotometer before and after invitro aging. Data were analyzed using chi square test with p &lt;0.05. Results: There was observed a significant variation in the shades of all the composites. There was a significant variation between the Nanocomposites and the microfilled composites. Conclusions: All composite resins depicted a color change and the size of the particles may have impacted the staining of the composites in vitro. Key words: Color, Composite Resins, Aging.

Effect of the thicknesses of bulk-fill composites on bonding strength.

This work evaluated the effects of thickness on resin bonding strength. We set the two bulk-fill composites Filtek Bulk Fill Posterior (FBF) and Tetric N-Ceram Bulk Fill (TBF) as the experimental groups and the two conventional composites Filtek Z100 (Z100) and Spectrum TPH (ST) as the control groups. The translucency parameter (TP), color difference, Vickers hardness (HV), and microtensile bond strength (μTBS) of dentine and the resin composites were measured at different depths. In each group, TP and HV decreased with the increase in thickness. At the same depth, the TP of the bulk-fill composites was higher than that of the conventional composites. At the same depth, the HV of the four different resin composites followed the order of Z100>FBF>TBF>ST (except for the upper surface). Except for FBF at 3 and 4 mm, all of the other groups showed no visible color change at all the tested thicknesses. Although the μTBS values of the four different composites obtained through the bulk-fill technique were lower than those of composites obtained through the incremental fill technique, the μTBS of the bulk-fill composites obtained through the bulk-filling technique can reach 30 MPa. Bulk-fill composites applied in single 4 mm increments can meet the requirements of clinical application. However, the color stability of some bulk-fill composites cannot be maintained.

Viscosity and thermal kinetics of 10 preheated restorative resin composites and effect of ultrasound energy on film thickness

ObjectiveThis study investigated viscosity and thermal kinetics of 10 selected preheated restorative resin composites and the effect of ultrasound energy on film thickness. MethodsA range of different resin composites was tested: Charisma Diamond, IPS Empress Direct, Enamel Plus HRi, Essentia, Estelite Omega, Filtek Z100, Filtek Z350 XT, Gradia, TPH Spectrum and VisCalor. A flowable resin composite (Opallis Flow) and two resin cements (RelyX Veneer, Variolink Esthetic LC) also were tested. Viscosity (Pa s) was measured at 37 °C and 69 °C (preheating temperature) using a rheometer. Film thickness (μm) was measured before and after application of ultrasound energy. Temperature loss within resin composite following preheating (°C/s) was monitored. Data were statistically analyzed (α = 0.05). ResultsViscosity at 69 °C was lower than at 37 °C for all materials except the flowable resin composite. Preheating reduced viscosity between 47% and 92% for the restorative resin composites, which were generally more viscous than the flowable materials. Film thickness varied largely among materials. All preheated resin composites had films thicker than 50 μm without ultrasound energy. Application of ultrasound reduced film thickness between 21% and 49%. Linear and nonlinear regressions did not identify any relationship between filler loading, viscosity, and/or film thickness. All materials showed quick temperature reduction following preheating, showing maximum temperature loss rates after approximately 10 s. SignificanceDistinct restorative resin composites react differently to preheating, affecting viscosity and film thickness. The overall performance of the preheating technique depends on proper material selection and use of ultrasound energy for reducing film thickness.

Color stability, Roughness, and Microhardness of Enamel and Composites Submitted to Staining/Bleaching Cycles

ObjectiveTo compare the effect of two bleaching systems (bleaching gel and whitening strips) on the color change, roughness, and microhardness of enamel and two resin composites. Material and methodsTwo cavities were prepared on bovine enamel specimens (n = 16) and restored with two composites: a nano-hybrid [Herculite Ultra (HU)] and a micro-hybrid composite [TPH Spectra (TS)]. Baseline color (CIE L*a*b*), roughness (μm), and microhardness (kgf/mm2) were measured using a spectrophotometer, optical profilometer, and Vickers microhardness (VHN) tester, respectively. The specimens were stained with coffee for 14 days, and randomized into two bleaching groups: gel and strips (n = 8), then submitted to a 10-day bleaching/staining test. Color, roughness, and microhardness were re-measured. The outcomes were analyzed using two-way ANOVA and Fisher’s-PLSD test (α = 0.05). ResultsGel significantly improved the color (ΔE 4.9–8.3) and increased the roughness (Ra 0.04–0.08 μm) of all substrates (p < 0.0001) compared to strips. Enamel color was significantly improved (ΔE 5.4–8.3) compared to that of HU (ΔE 2.6–4.9) and TS (ΔE 2.0–4.9) with either gels or strips. TS roughness (0.03–0.08 μm) was significantly higher than that of enamel (0.01–0.05 μm) and HU (0.02–0.04 μm). Enamel had significantly reduced microhardness compared to HU (p = 0.0144). ConclusionGels produced the greatest color improvement and roughness compared to strips. Enamel had significant color improvement but had the greatest decrease in microhardness. Clinical significanceThere was unacceptable color change between enamel and the composites after the combined cyclic effects of staining and bleaching.

Evaluación instrumental colorimétrica de resinas compuestas que imitan dentina en comparación a escala vita clásica

Objetivos: Determinar cuantitativamente en 7 marcas comerciales diferentes de resinas compuestas que simulan dentina (Filtek Z350XT® 3M ESPE ™, Miris 2® Coltène™, Empress Direct® Ivoclar Vivadent ™, Opallis® FGM™, TPH Spectra® DentsplySirona ™ Tetric N Ceram® Ivoclar Vivadent™, Brilliant Everglow® Coltène ™) codificado como Vita Clásica Vita Zahnfabrik™) A2 y A3 o un tinte equivalente, la diferencia de color (ΔE) con la escala Vita Classic para esa codificación en un fondo blanco o negro. Materiales y métodos: Estudio descriptivo in vitro. Se utilizaron 7 marcas de resinas compuestas (N 35) en tonos A3 y A2, se realizaron discos de 10 mm de diámetro y 2 mm de grosor, medidos con espectrofotometría en 2 fondos con instrumento Vita Easyshade V® Vita Zahnfabrik™. Se analizaron los valores obtenidos en CIELAB obteniendo ΔE. Se realizó una prueba ANOVA 2 factores (a0,05). Resultados: El ΔE más cercano a la escala Vita Clásica® fue dado por TPH Spectra® DentsplySirona™ A2 (1.02 ±.69), el ΔE mayor fue de Filtek Z350XT® 3M ESPE™ (69.31±.50).Conclusión: Existen claras diferencias entre las resinas de las marcas comerciales estudiadas y la escala Vita Clásica. En fondo negro un 71,4% de todas las muestras y en fondo blanco un 92,8% están sobre un ΔE 5, significando que las diferencias entre sus tintes son consideradas inaceptables clínicamente. Ninguna de las marcas de resinas compuestas cumple con las características colorimétricas al compararlas con la escala Vita Clásica.

Influence of Neuroticism on the Prognosis of Nanoceramic and Microhybrid Composite Restoration: A Comparative 1-year Clinical Study.

ABSTRACTAim:This study aimed to compare the clinical performance of nanoceramic and microhybrid-based composite restorations in adult patients with different personality traits.Materials and Methods:Patients in accordance with the inclusion and exclusion criteria were asked to complete the BFI (Big Five Inventory) questionnaire. Of a total of 323 patients, 124 (67 males and 57 females) patients were categorized into agreeableness and neuroticism traits and were included in the study. The patients were randomly divided into two subgroups: SG I A (n = 31) and II A (n = 31) for microhybrid composite (Spectrum TPH 3, Dentsply/DeTrey, Konstanz, Germany), SG I B (n = 31) and II B (n = 32) for nanoceramic composite restorations (Ceram X mono, Dentsply/DeTrey, Germany). At baseline, 6 and 12 months, the restorations were evaluated using the Modified USPHS (United States Public Health Service) evaluation criteria. The Pearson chi-square and the Fisher’s exact test were used to assess the difference between the personality traits and restorative material groups where a probability value of P < 0.05 was considered to be statistically significant.Result:Most of the restorations scored alfa (A), whereas very few scored bravo (B) in all the subgroups. However, there were no charlie (C) or delta (D) scores. Overall, Spectrum TPH and Ceram x mono displayed superior performances in retention and postoperative sensitivity than all the other clinical parameters. Furthermore, Ceram x mono restorations showed more surface roughness than Spectrum TPH. No statistical differences in the restoration performance were found between both personalities and restorative material types.Conclusion:Although neuroticism has an effect on various health outcomes, its impact on the clinical performance of composite restorations during the follow-up period was not observed. In addition, there was no difference between the performance of nanohybrid and microhybrid composite.

Degree of Conversion of Nanoceramic and Microhybrid Composites Activated by Different Polymerization Modes at Different Intervals: An In Vitro Comparative Study

This is an in vitro study to evaluate the degree of conversion (DC) of nanoceramic and microhybrid composites activated by different polymerization modes at different intervals. To determine the DC of two resin composites at different time intervals and modes of polymerization on DC. Two commercially available composite resins-nanoceramic (Ceram X, Dentsply) and microhybrid (Spectrum TPH, Dentsply)-were used in this study. A total of 80 cylindrical samples (n = 40 each) were made by packing the composites in one increment into (5 × 2 mm) Teflon molds and cured using a light-emitting diode (LED) at an irradiance of 1,200 mW/cm2. Each group was further divided into two groups (n = 20) based on the curing modes (20 seconds, 40 seconds). These 20 samples were further subdivided (n = 10) based on the time interval (2 days, 7 days). Degree of conversion was assessed by Fourier-transform infrared spectrophotometer (FTIR) using a direct technique (attenuated total reflectance) on the top surface of the samples. Degree of conversion was measured for samples cured for 20 seconds (n = 10) and 40 seconds (n = 10) after 2 days and 7 days during which the samples were stored in an incubator at 37°C, 90% ± 10% relative humidity. The results obtained were statistically analyzed using two-way and three-way analysis of variance (ANOVA) test and p value set at (<0.005) significance level. Degree of conversion for the tested composites varied between 44% and 55% for Ceram X and 42% and 45% for Spectrum TPH. A significant difference was observed in DC for Ceram X samples for different polymerization modes (20 seconds and 40 seconds) as well as at 2-7 days measurement, whereas Spectrum TPH did not show any significant difference for polymerization modes. Ceram X demonstrated high DC values compared with that of Spectrum TPH with regard to two different polymerization modes. Lesser the time required for conversion and less the residual monomer left, better is the prognosis of the restoration, and better is the patient satisfaction.

Influence of Light-Curing Intensity on Color Stability and Microhardness of Composite Resins.

The purpose of this study was to evaluate the intensity of light-curing units and its relationship with the color stability and microhardness of composite resins with different shades subjected to a thermocycling procedure. Eighty blocks (5.0 × 2.0 mm) of TPH Spectrum composite resin (Dentsply Sirona) were produced and distributed into four groups according to the light-curing units (EC 450, ECEL; Valo, Ultradent) and color of the resin material (A3; C3) (n = 20). Within each group, color stability was measured on half the sample (n = 10) using a UV-2450 visible UV spectrophotometer (Shimadzu), and Knoop hardness was measured on the other half (n = 10) using an HMV 2000 microhardness tester (Shimadzu) before and after thermocycling (12,000 cycles, 5°C and 55°C). Mann-Whitney test was performed on the color stability data; the microhardness data were analyzed using a three-way analysis of variance (ANOVA) and Tukey test (α = .05). The ANOVA results showed that thermocycling, distinct light intensity, and different colors of resin materials influenced the microhardness of the composite resins, which was evidenced by the A3 composite resin light-cured with a Valo polywave showing higher hardness values. There was no statistical difference in the color stability of the A3 composite resin; however, the C3 composite resin light-cured with an EC 450 singlewave light-curing unit showed higher color alteration values. In general, the Valo polywave light-curing unit imparted better mechanical property and color stability to both shades of the composite resins. The different shades of resin material influenced the hardness of the composite resins. Therefore, the light intensity of the light-curing units should be evaluated and monitored, as the amount of light intensity will interfere in the quality and longevity of resin restorations.

The Effect of Simulated Field Storage Conditions on Dental Restorative Materials for Military Field Use.

Dental readiness, one critical component of medical readiness, is adversely impacted by dental emergencies. Many dental emergencies require restorative materials such as glass ionomers, resins, and zinc oxide eugenols to remedy them. The Authorized Dental Allowance List (ADAL) and Authorized Medical Allowance List (AMAL) contain the equipment and materials used by Navy dentists to treat Sailors and Marines. These supplies are subjected to harsh storage conditions on deployments. Much is known about how materials behave when stored at room temperature, but less is known about how their properties are affected after exposure to high temperatures and humidity. We subjected five dental restorative materials to storage in aggravated conditions, and then tested them to determine which products are more robust. Unopened packages of Fuji Triage, Fuji IX GP (both GC America Inc., Alsip, Illinois), TPH Spectra ST Low Viscosity, Intermediate Restorative Material (both Dentsply Sirona, York, Pennsylvania), and Herculite XRV (Kerr Corporation, Orange, California) were exposed to 0, 5, or 10days' storage at 30-60°C with 95% relative humidity. After storage in these aggravated conditions, we tested the compressive strength, hardness, elastic modulus, flexural strength, flexural modulus, sorption, and solubility of each material. The physical properties of all materials were affected by storage in aggravated conditions, though the properties of some materials degraded more than others. Both glass ionomers, Fuji Triage (P=0.0012) and Fuji IX GP (P=0.0031), and the composite Herculite XRV (P=0.0253) lost compressive strength after 5 or 10days in aggravated conditions. The hardness values for all materials were affected (P<0.05) by the aggravated conditions, though the elastic modulus of TPH Spectra was not affected (P>0.05). None of the materials lost flexural strength (P>0.05) or had changes in their flexural modulus (P>0.05). The water sorption behavior of Fuji Triage (P=0.0426) and Fuji IX GP (P=0.0201) changed after 10days of aggravated storage, and the solubility of all materials was altered by the harsh conditions. Some materials degrade more than others in aggravated conditions. Both resin composite materials were more resistant to high temperatures and humidity levels than the glass ionomers tested. These changes in physical characteristics should be considered when reviewing or optimizing the ADAL/AMAL for different projected operational environments.

Instrumental and visual evaluation of the color adjustment potential of resin composites.

To evaluate the instrumental and visual color adjustment potential (CAP-I, CAP-V), of resin composites. Resin composites tested were Omnichroma, Filtek Supreme Ultra, TPH Spectra, Herculite Ultra, and Tetric EvoCeram. Two types of specimens, "dual" and "single" were evaluated. For dual specimens, class I preparations (4 mm-diameter, 2 mm-depth), were created in denture teeth and restored with test resin composites. For single specimens, replications of denture teeth were created using the test resin composites (n = 5) and compared with unrestored denture teeth. Reflectance values were obtained using a spectroradiometer. CAP-I and CAP-V were calculated. Fisher PLSD intervals for comparison of means were calculated at the 0.05 level of significance. CAP-I ranged between 0.02 and 0.67. The Fisher PLSD interval for comparisons between single/dual color differences was 0.09 (P < .0001, power 1.0) and for comparisons between materials and shades 0.18 and 0.33, respectively (P < .0001, power 1.0). CAP-V ranged between 0.16 and 0.60. The Fisher PLSD interval for comparisons between single/dual visual color differences was 0.05 (P < .0001, power 1.0) and 0.08 and 0.14 for comparisons between materials and shades, respectively (P < .0001, except Herculite Ultra-Tetric EvoCeram and certain shade pairs). Instrumental color differences and visual rating of single specimens were the greatest for Omnichroma, indicating the largest mismatch, while the instrumental and visual color differences of dual specimens were the smallest. Omnichroma had the most pronounced CAP-I followed by Tetric EvoCeram>TPH Spectra = Filtek Supreme Ultra >Herculite Ultra. Similarly, Omnichroma exhibited the most pronounced CAP-V followed by Tetric EvoCeram>TPH Spectra = Herculite Ultra = Filtek Supreme Ultra. Resin composites with pronounced CAP blends with surrounding enamel and dentin, resulting in reduced color differences and therefore improving the esthetic appearance of the restoration, simplifying the shade matching and compensating for any color mismatch.

Depth of cure of high-viscosity bulk-fill and conventional resin composites using varying irradiance exposures with a light-emitting diode curing unit.

The purpose of this study was to determine the depth of cure (DOC) of three resin-based composites (RBCs) using varying irradiance exposures with a corded light-emitting diode curing unit. DOCs for Filtek Z250, TPH Spectra, and Tetric EvoCeram Bulk Fill were determined using the International Organization for Standardization (ISO) Standard 4049. The RBCs were light-polymerized using three different power modes and manufacturer-recommended curing times. Irradiance was determined using a spectrometer sensor and the total energy density was calculated for each power mode and concomitant polymerization time. The DOC data were analyzed with a two-way analysis of variance and Tukey's post hoc test. Tetric EvoCeram Bulk Fill produced significantly greater DOCs than TPH and Z250 (P < 0.05) for all three power mode settings. Overall, the DOC of Tetric EvoCeram Bulk Fill was greater than those of TPH and Z250 at all power settings, but the individual RBCs did not show a significant DOC difference among the three power settings (P > 0.05).

Effect of local anesthesia containing vasoconstrictor on sealing ability of dentin with two adhesive systems: Dye leakage and scanning electron microscopy study.

Objectives:To evaluate the effect of 2% lignocaine containing 1:80,000 adrenaline on the microleakage and ultrastructure of resin tooth interface using an acetone based total etch adhesive (Prime and Bond NT) and an ethanol water based self etch adhesive system (Xeno III).Materials and method:Class V cavities were prepared on buccal surfaces of 72 maxillary first premolars scheduled for orthodontic extraction. In 36 premolars procedure was performed under local anaesthesia (LA) and in other 36 teeth without LA. Restorations were done with hybrid composite Spectrum TPH using either Prime and Bond NT or Xeno III bonding agents.Results:Administration of 2% lignocaine with 1:80,000 adrenaline significantly reduced microleakage and improved quality of hybrid layer and tubular penetration in Prime and Bond NT specimens; but no significant effect was observed in Xeno III specimens.Conclusion:Under clinical conditions, administration of LA reduced microleakage and improved quality of hybrid layer and tubular penetration in total etch adhesive systems.

Clinical Performance and Epidemiologic Aspects of Fractured Anterior Teeth Restored with a Composite Resin: A Two-Year Clinical Study.

To investigate the etiologic factors, effect of age and gender on dental trauma, and to evaluate the performance of composite resin on the fractured crown of permanent anterior teeth. Over a 2-year period, 73 permanent teeth from 51 patients with dental trauma were treated with direct composite resin restoration. Informed consent and standardized trauma forms were completed by the patient; teeth were restored with a submicron hybrid composite resin (Spectrum TPH) and respective adhesive system (Prime&Bond NT). Sixty-nine teeth were directly restored without fiber posts, while four were treated with fiber posts. Two experienced clinicians, besides the operator, evaluated each restoration at 6-, 12-, and 24-month follow-ups according to US Public Health Service (USPHS) criteria for the following characteristics: anatomical form, marginal adaptation, color match, marginal discoloration, surface roughness, and caries. Data were analyzed using the Wilcoxon Signed Rank, Kruskal-Wallis, Mann-Whitney U, and Siegel and Castellan tests. A total of 73 traumatized teeth in 51 patients aged from 14 to 64 years (mean age 25.47 ± 14.058 years) were assessed according to the Ellis classification and restored over a 2-year period. Crown fractures were more common in the maxilla (84.9%) and caused by falls (58.8%). At the end of 24 months, a total of ten restorations were lost. The survival rate after 24 months was 82.14%. There were statistically significant differences in marginal adaptation between the 6-, 12-, and 24-month follow-ups. Although changes in marginal discoloration over time were not significant (p = 0.194), changes in color match were significant (p = 0.029). Within the limitations of this study, direct composite restorations were accepted as clinically satisfactory.

In Vivo Biodegradation of bisGMA and Urethane-Modified bisGMA-Based Resin Composite Materials.

The aim of this study was to compare the levels of in vivo chemical degradation sustained by bisphenyl-glycidyl-dimethacrylate (bisGMA)-based and urethane-modified bisGMA-based resin composites. A cohort of 58 patients was recruited for the study. Human salivary esterase activity (HSDE) was measured for each patient prior to restoration placement. Class V or III composite restorations without occlusal contacts were placed in adult patients using a 3-step adhesive (Scotchbond MP, 3M) and 1 of 2 resin composites: a traditional bisGMA-based (Z250; 3M) ( n = 28) or a urethane-modified bisGMA-based composite (TPH Spectra, Dentsply) ( n = 30). Patients followed a 2-min rinse (saline containing 20% ethanol) protocol before, immediately after, and 7 days after restoration placement. The rinse samples were analyzed for the presence of bisphenol A (BPA) and bishydroxypropoxyphenylpropane (bisHPPP), a bisGMA breakdown product, using high-performance liquid chromatography in combination with mass spectrometry. The overall mean ± standard error (SE) HSDE activity was 23.4 ± 1.9 U/mL, with no statistical difference between the Z250 (22.6 ± 2.8 U/mL) and TPH (24.1 ± 2.1 U/mL) groups ( P = 0.69). BPA was not detected from any rinse samples. BisHPPP was detected from both composites only in rinse samples immediately after resin composite placement (0.59 µg/mm2 ± 0.16 and 0.68 µg/mm2 ± 0.16 for Z250 and TPH, respectively, P = 0.767). There was no statistically significant correlation between HSDE and amount of bisHPPP obtained from the saliva for the Z250 group ( r = 0.071, P = 0.723), TPH group ( r = 0.266, P = 0.155), and both groups combined ( r = 0.080, P = 0.549). Conventional commercial resin composite materials used in the current study did not release any detectable amount of BPA and only showed detectable levels of bisHPPP for a short term after placement, suggesting that hydrolytic consumption of any available resin substrate is fast and the generated products are rapidly diluted below the detection level limit (<20 ppb) in the oral cavity. This short-term release of bisHPPP was not significantly affected by material type or esterase level in the saliva. Knowledge Transfer Statement: This clinical study demonstrated that the duration and degree of biodegradation of 2 representative formulations of resin composites was limited in both duration and amounts of detectable matrix derived degradation products. No significant level of potential biohazards was released following the application of the resin composites. The results of this study can help oral care professionals address concerns from their patients about possible health issues regarding the application of resin composite restorative materials.

Surface Degradation of Resin-based Materials by Pediatric Syrup Containing Amoxicillin under Erosive Challenge

Objective: To investigate the effect of a pediatric syrup containing Amoxicillin on resin-based on the surfaces of resin-based materials under pH cycling. Material and Methods: Cylindrical samples (n=60) of a compomer (Freedom) and a microhybrid composite (TPH Spectrum) were prepared following the manufacturer’s instructions. The specimens were divided into two groups and treated for 30min, twice a day, for 14 days with a pediatric syrup containing Amoxicillin, Amoxil™ 500mg/5ml (experimental group) or Distilled water (control group). During the 14 days, the samples were submitted to pH cycling (3h in demineralizing, 20h in remineralizing saliva, and 1h for treatment). The surface roughness was evaluated at baseline, on the 7 th and 14 th days of erosive challenge using a profilometer and illustrated by SEM. The data were statistically analyzed by one-way ANOVA, Tukey HSD and paired T- tests (p 0.05). Results: After 7 days, it was observed no erosion (p = 0.674) for THP Spectrum (0.19 Ra) and an increasing of Ra (p = 0.02) for Freedom (19.95 Ra). After 14 days, it was observed an increasing of Ra for both THP Spectrum (0.56 Ra) and for Freedom (3.44 Ra), demonstrating that the degradation was treatment and time-dependent (p < 0.001). The pediatric syrup containing Amoxicillin increased the surface roughness of the TPH Spectrum surface one and a half times (p = 0.003) and the surface roughness of Freedom was increased by more than two times (p < 0.001). SEM images showed different aspects of the surfaces of the two materials with a loss of integrity to both. Conclusion: The pediatric syrup containing Amoxicillin under pH cycling increased the roughness of the both tested resin-based restorative materials.

Clinical evaluation of microhybrid composites in noncarious cervical lesions: 24-month results.

To evaluate the clinical performance of two different microhybrid resin composites in noncarious cervical lesions (NCCLs) after 24 months. Ninety-seven NCCLs were restored with either TPH Spectrum (n = 48) or Filtek Z250 (n = 49) using an etch-and-rinse adhesive in 20 patients. The restorations were clinically evaluated using modified United States Public Health Service criteria for retention, color match, marginal discoloration, marginal adaptation, surface texture, anatomic form, postoperative sensitivity, and secondary caries. The restorations were assessed 1 week after placement (baseline) and after 6, 12, and 24 months. Restoration survival rates were calculated using the Kaplan-Meier procedure estimator, and a log-rank test was used to compare the survival distributions (P < 0.05). Statistical analysis was undertaken using Pearson's Chi-square test and Fisher's exact test to assess differences among the restorative materials (P < 0.05). Cochran's Q-test was employed for evaluating differences in the same restorative material between recall periods. The retention rates were 100% at 6 months, 89.6% and 91.8% at 12 months, and 85.4% and 89.8% at 24 months for TPH and Z250, respectively. TPH showed a statistically significant difference in marginal discoloration between the baseline and 24 months results (P < 0.05). Both TPH and Z250 showed statistically significant differences in marginal adaptation between the baseline and 24 months results (P < 0.05). Over the 24-month period, both microhybrid resin composites demonstrated acceptable clinical results in NCCLs.

Etiologic factors and clinical evaluation of restored fractured anterior teeth: an observational study.

The aims of this study were to investigate the etiologic factors and to evaluate performance of composite resin on fractured crown in permanent anterior teeth at 6 and 12 months. Records from 51 patients were retrieved from a Dental School Clinic, comprising 73 fractured anterior teeth directly restored with a submicron hybrid composite (Spectrum TPH) resin and respective adhesive system (Prime and Bond NT) were evaluated. The United States Public Health Service criteria were used to assess the clinical evaluation. Data were analyzed using the Wilcoxon Signed Rank, Kruskal-Wallis, Mann-Whitney U, and Siegel and Castellan tests. Seventy-two maxillary incisors and one canine of 51 patients were evaluated. The patient's age at the time of therapy ranged from 14 to 64 years old (mean 25.47). Mostly observed crown fracture was seen in upper incisors (84.9%) and due to falls (58.8%). At the 6-month follow-up, one patient lost one restoration and at the 12-month, one patient lost one and one lost two restorations. A statistically significant difference was found in terms of marginal adaptation between 6 and 12 months. In this short-term observation period, remaining tooth structure was conserved and good patient compliance was achieved. Factors such as esthetic and/or cost should be considered to indicate the direct composite restorations.