The effect of sealer type and obturation technique on the fracture resistance of endodontically treated roots.

OBJECTIVE: This study evaluated the effect of sealer type with various obturation techniques on the fracture resistance of root filled teeth. MATERIALS AND METHODS: Eighty mandibular premolars were collected, and root canals of 70 of them were prepared by Mtwo system up to 40/04. Thirty teeth were obturated using TotalFill BC sealer, and 30 using AH Plus sealer, with one of the obturation techniques (N = 10), namely cold lateral compaction (CLC), warm vertical compaction (WVC), and single cone (SC). Ten teeth were left without obturation as a positive control, and the other 10 teeth were not prepared serving as a negative control. Teeth were stored for 3 weeks, and the crowns were separated and the roots were subjected to fracture test using a universal testing machine. RESULTS: Data was analyzed by ANOVA followed by Tukey's test. Fracture resistance of the TotalFill groups was significantly higher than the AH Plus groups in each obturation technique, and SC had the highest fracture resistance regardless of sealer used (P < 0.05). Obturation of the root canal by TotaFill BC sealer increased the calcium/phosphorous ratio in the dentin of the root. CONCLUSIONS: Obturation with TotalFill BC sealer improved the fracture resistance of the roots more than AH Plus sealer, and obturation with SC resulted in higher fracture resistance than CLC and WVC. CLINICAL RELEVANCE: Obturation of the root canal with Bioceramic sealer with single cone obturation technique could reduce the incidence of vertical root fracture.

Coronal discoloration induced by calcium silicate-based cements used in full pulpotomy in mature permanent molars: a randomized clinical trial.

OBJECTIVES: This study aimed to randomly compare in vivo coronal discoloration at 6 and 12 months after full pulpotomy in mature permanent molars using MTA, Biodentine, and TotalFill and to investigate the effect of variables such as remaining buccal wall thickness and time to achieve hemostasis. MATERIALS AND METHODS: One hundred eight teeth that met the inclusion criteria received full pulpotomy and were randomly divided into 3 groups via a block randomization technique according to the calcium silicate cement (CSC): ProRoot WMTA, TotalFill, or Biodentine. Assessment of tooth color was carried out using a spectrophotometric device (VITA Easyshade Compact) after composite placement (T0), at 6- and 12-month follow-up. Buccal wall thickness and time to hemostasis were recorded. The primary outcome measure (color change ΔE) was calculated, and the results were analyzed by three-way ANOVA and crosstabulations in relation to material type and effect of variables. RESULTS: Four cases were excluded after pulpotomy failure; 81 teeth were evaluated at 6 months and 95 teeth at 12 months. All CSCs caused tooth discoloration (defined as ΔE > 3.7); MTA significantly caused the highest color change at 6- and 12-month follow-up (76% (19/25) and 87.5% (28/32), respectively) compared to Biodentine (41% (9/22), 48% (13/27)) and TotalFill (44% (15/34), 53% (19/53)) (p = 0.022, p = 0.002), while no significant difference was found between the Biodentine and TotalFill groups (p = 0.813, p = 0.8). Buccal wall thickness (above or below 2.7 mm) had a significant effect on the degree of discoloration (p = 0.004). CONCLUSIONS: The 3 CSCs caused tooth discoloration based on the threshold of ΔE > 3; the remaining buccal wall thickness was a significant factor. The use of Biodentine and TotalFill instead of MTA is encouraged to minimize discoloration. CLINICAL RELEVANCE: While experimental studies report coronal discoloration after CSCs use, clinical data is lacking. This study assessed discoloration using a spectrophotometric device. The use of materials with lower discoloration potential in pulpotomy is encouraged. TRIAL REGISTRATION: The study was registered with clinical trial registration number: NCT04346849 on 14.4.2020.

Reframing perceptions in operative dentistry relating evidence-based dentistry and clinical decision making: a cross-sectional study among Jordanian dentists.

BACKGROUND: The aim of the current study was to investigate current dental practice in operative dentistry in Jordan, and the relationship between evidence-based dentistry in caries research and decision making in clinical practice in operative dentistry. MATERIALS AND METHODS: This cross-sectional study was conducted through a survey of dentists in Jordan. The survey aimed to explore the degree of knowledge and practice of evidence-based dentistry in caries research the dentists possess regarding clinical decision making in operative dentistry. The sample size was composed of (5811) dentists whom registered in Jordan Dental Association database. Descriptive statistics were generated and Chi-square test was used to examine associations between the different variables and the significance level was set at P < 0.05. RESULTS: 4000 responses were collected from the web-survey, response rate (68.83%). Nearly half of the surveyed dentists focus on the chief complaint of their patients (n = 2032, 50.8%) rather than doing full mouth assessment. Nearly two-thirds of dentists (n = 2608, 65.2%) treat lesions confined to enamel with operative treatment. Half of dentists use operative treatment when asked about the routine management of radiographically detected proximal caries confined to enamel. When treating incipient lesions, the majority (n = 3220, 80.5%) use preventive treatment. Three-quarters of dentists (n = 2992, 74.8%) treat deep dentinal caries by removing just the soft infected carious dentin, and treated old failed restorations with replacement. CONCLUSION: In operative dentistry, the evidence-based research is not implemented clinically. To optimize relationship between evidence-based dentistry and clinical decision-making, dental curriculum has to be updated and modified constantly.

Push-Out Bond Strength of Calcium Silicate-Based Cements in the Presence or Absence of a Smear Layer.

Objectives: Variations between the material compositions and the presence of a smear layer on the dentin surface may influence the bond strength of the material, thus this study evaluated the push-out bond strength of different calcium silicate materials to root dentin in the presence or absence of smear layer. Materials and Methods: The palatal canal of sixty maxillary first premolars were prepared and divided into three groups according to the materials to be used: ProRoot WMTA, Biodentine, and TotalFill FS. Each group was then divided into two subgroups; with and without a smear layer. Roots were sectioned into three slices and filled with the tested materials. Push-out bond strength of materials was measured by universal machine. Results: Bond strength of Biodentine was significantly higher than the MTA and TotalFill FS in the presence or absence of smear layer. Overall, removing the smear layer reduced the bond strength of the three materials. The reduction was significant for MTA and TotalFill FS but not for Biodentine. Conclusions: Biodentine demonstrated the highest bond strength to radicular dentin followed by MTA, and then TotalFill FS. Overall, removal of the smear layer from dentin surface reduced the bond strength of the calcium silicate root repair materials.

The effect of different calcium silicate-based pulp capping materials on tooth discoloration: an in vitro study.

BACKGROUND: Variation in the composition of calcium silicate-based pulp capping materials could influence the discoloration potential of some of these materials, thus affecting the color and aesthetic appearance of the coronal tooth structure. Furthermore, contact with blood if hemostasis is not fully achieved may enhance this discoloration for some materials. Therefore the aim of this study was to evaluate in vitro the color change of coronal tooth structure after placing various calcium silicate-based materials in the pulp chamber in the presence or absence of blood. MEHTODS: Maxillary extracted premolars (n = 144) were sectioned and the crowns were separated from the roots. Pulp chambers were prepared to a standard size and then the tested materials (GMTA Angelus, ProRoot WMTA, Biodentine, TheraCal, and TotalFill) were placed with saline or with blood. Color change was assessed by spectrophotometry; prior to and after material placement at different time intervals of 24 h, 1 week, 1 month, 3 months, and 6 months. Color change (ΔE) values were calculated and statistically analyzed. RESULTS: In the saline groups, Biodentine caused the least color change, while GMTA and WMTA caused the highest color change which were significantly different from the others (p < 0.001), TotalFill and TheraCal caused moderate changes. Adding blood increased the ΔE overall the tested materials to various degrees. Biodentine was the most affected by the blood, while MTA groups were the least affected, followed by TotalFill and then TheraCal. The increase in ΔE was significant over time up to 3 months, after which the increase was not significant. CONCLUSIONS: Overall, WMTA and GMTA caused the most severe discoloration. In saline, Biodentine caused the least discoloration, but it was the most affected by the presence of blood, although it still caused the least discoloration similar to that observed with TotatFill. TheraCal caused moderate discoloration but more than that caused by Biodentine and TotalFill.

The effect of calcium hydroxide on dentine composition and root fracture resistance of human teeth: An in vitro study.

The purpose of this study was to evaluate the effect of calcium hydroxide [Ca(OH)2 ] on dentine composition and root fracture resistance. Root canals of fifty extracted mandibular premolars were prepared and divided into five groups (N = 10). Canals were filled with non-setting Ca(OH)2 or left empty and were subsequently stored in phosphate buffered saline for 7, 14, 30, or 90 days, respectively. Ca(OH)2 was then washed out, and roots were separated from the crowns and subjected to fracture strength test. Fractured fragments were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results showed a significant and progressive reduction in fracture resistance the longer the duration of exposure to Ca(OH)2 , and the fracture resistance in teeth exposed for 90 days was significantly lower than in any other group. SEM revealed cracks in the dentine surfaces that had been exposed to Ca(OH)2 . FTIR showed a significantly lower mineral to matrix ratio in roots exposed to Ca(OH)2 for 30 and 90 days than seen in roots exposed for a shorter duration. XRD analysis revealed a reduction in dentine crystallinity. It was concluded that Ca(OH)2 significantly reduced the fracture resistance of the roots overtime. Exposure to Ca(OH)2 reduced the mineral to matrix ratio and crystallinity of the dentine.

Reframing Perceptions in Restorative Dentistry: Evidence-Based Dentistry and Clinical Decision-Making.

OBJECTIVES: The worldwide interest of both dentists and patients in esthetic dentistry has affected decision-making in dental practice. The aim of this study was to investigate contemporary dental practice in restorative dentistry and the relationship between evidence-based dentistry in caries research and decision-making in clinical practice in restorative dentistry. METHODS: The study was conducted through a structured questionnaire distributed randomly at the Jordanian Dental Association registered dentists in Jordan. The questionnaire aimed to clarify the degree of knowledge and practice of evidence-based dentistry in caries research the dentists hold regarding clinical decision-making in restorative dentistry. RESULTS: The majority of the surveyed dentists (77%) treat teeth with irreversible pulpitis with root canal treatment rather than vital pulp therapy. 13.8% routinely insert a post and 23% routinely crown the tooth after root canal treatment regardless of the remaining tooth structure. Badly damaged teeth are treated with full crowns in 72% of the cases. Regarding Hollywood smile or smile makeover, the majority of dentists choose conservative approaches, and implants were the first choice to replace missing teeth for 93.8% of the surveyed dentists. CONCLUSION: A higher degree of implementation of evidence-based dentistry in clinical decision-making was found in Prosthetic Dentistry than in Endodontics. Yet, the gap between evidence-based data and clinical practice needs bridging. More emphasis on communicating these data to educators to integrate them into the dental curriculum is a must.

The effect of adding graphene oxide nanoplatelets to Portland cement: Potential for dental applications.

BACKGROUND: The potential of graphene-based materials to improve the physiomechanical properties of Portland cement-based materials without compromising biocompatibility is of interest to dental researchers and remains to be discovered. AIM: This study investigated the effects of adding graphene oxide nanoplatelets (GONPs) on the surface microhardness and biocompatibility of Portland cement. MATERIALS AND METHODS: Three prototype Portland cement powder formulations were prepared by adding 0, 1, and 3 wt % GONPs in powder form to Portland cement. Prototype cement specimens were in the form of disks, with a diameter of 10 mm and a thickness of 2 mm. In experiment 1, surface microhardness was measured using the through indenter viewing hardness tester, 20 surface hardness values were obtained from all specimens. In experiment 2, Balb/C 3T3 fibroblasts were cultured with the material disks and the viability of cells was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. STATISTICAL ANALYSIS: The data were analyzed using the analysis of variance followed by Dunnett test (α = 0.05) or Tukey test (α = 0.05). RESULTS: In response to material disks, the addition of 1 wt % GONPs had a proliferative effect on cells at day 3 and day 7 with a significant difference from the control. The addition of 3 wt % GONPs showed a remarkable increase in surface microhardness; however, it exhibited initial cytotoxicity. CONCLUSIONS: The addition of 1 wt % GONPs to Portland cement improved surface microhardness without compromising biocompatibility; therefore, it has a greater potential for dental applications. The results of this work give other researchers leads in future assessments of this prototype material.

Biocompatibility evaluation of Jordanian Portland cement for potential future dental application.

BACKGROUND: The demand for novel Portland cement (PC)-based formulations to be used in dental applications is ever increasing in viewing the foregoing knowledge on the favorable effects of these formulations on cellular proliferation and healing, leading to treatment success. AIM: This study investigated the effect of white and gray mineral trioxide aggregate (W-MTA and G-MTA) and white and gray Jordanian PC (W-PC and G-PC) in their raw state on the viability of Balb/C 3T3 fibroblasts using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MATERIALS AND METHODS: Materials were prepared in the form of disks, with a diameter of 5 mm and a thickness of 2 mm. In the first experiment, Balb/C 3T3 fibroblasts were cultured with the material disks using culture plate inserts. In the second experiment, material elutes were added to cultured cells. The elutes were prepared by adding 2 ml serum-free media to 10 disks of each material and then incubated at 37°C for different time intervals. Material elutes were analyzed using ion chromatography for traces of calcium. The data were analyzed using analysis of variance followed by Dunnett test (α = 0.05) or Tukey test (α = 0.05). RESULTS: In response to material disks, G-PC had a proliferative effect on cells at day 1 and day 2 with a significant difference from the control at day 1. G-MTA reduced cell viability with a significant difference from the control level at day 2. Elutes of PC showed biocompatible and even proliferative effects on Balb/C 3T3 fibroblasts. Calcium ions were found to leach continuously over the measurement period for all the materials tested in this work. CONCLUSION: Jordanian PC in its raw state was found to be biocompatible, and the results of this work give promise of its wider use as a base for further development to improve the physiochemical and mechanical properties of the material.

The effect of obturation techniques on the push-out bond strength of a premixed bioceramic root canal sealer.

OBJECTIVES: The aim of the study was to evaluate the effect of obturation techniques on the push-out bond strength of a premixed bioceramic (TotalFill BC) root canal sealer to root canal dentin surface. METHODS: The palatal root canal of sixty extracted human maxillary first premolar were prepared with Mtwo rotary system, teeth were divided into two groups; according to the sealer to be obturated with; TotalFill BC sealer and AH Plus sealer. Each group was then divided into three subgroups (n = 10) according to the obturation technique; cold lateral compaction, single cone, and warm vertical compaction. After obturation teeth were stored in an incubator for two weeks. Three slices of 1.5 mm thickness were then obtained from each root. Bond strength of obturation materials to root dentine was measured using push-out test by universal testing machine. Data were analyzed using ANOVA followed by Tukey's test. Mode of failure was determined by optical microscope examination. RESULTS: Overall, the push-out bond strength of TotalFill BC sealer was significantly higher than that of AH Plus sealer (P < 0.001). The obturation technique had no significant effect on the bond strength of TotalFill. While the bond strength of AH Plus was significantly affected, warm vertical compaction and single cone groups displayed lower bond strength than cold lateral compaction group (P < 0.05). Mixed mode of failure was most predominant in all groups. CONCLUSIONS: TotalFill BC sealer showed a higher push-out bond strength than AH Plus sealer, and the obturation technique significantly affected AH Plus sealer but not the TotalFill. CLINICAL SIGNIFICANCE: Warm vertical compaction significantly reduced the bond strength of the resin based AH Plus sealer compared to cold lateral compaction, but this was not significant with the bioceramic TotalFill BC sealer. Single cone technique could be used with bioceramic sealer which make the obturation faster and easier.

Comparison of the Photosensitivity of Biofilms of Different Genera of Cariogenic Bacteria in Tooth Slices.

This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria ( Streptococcus mutans , Lactobacillus casei , Streptococcus salivarius and Actinomyces viscosus ) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of S. mutans , L. casei and A. viscosus in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. S. salivarius was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria (Streptococcus mutans, Lactobacillus casei, Streptococcus salivarius and Actinomyces viscosus) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of S. mutans, L. casei and A. viscosus in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. S. salivarius was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.

Correlation of Dental and Skeletal Malocclusions in Sagittal Plane among Saudi Orthodontic Patients.

AIM: Whether or not the dental relationship correlates with skeletal relationship in the sagittal plane is an area of interest for orthodontic diagnosis and treatment planning. Thus, the aim of this study was to investigate the correlation of the dental malocclusion and the skeletal malocclusion in the sagittal plane among Saudi orthodontic patients. MATERIALS AND METHODS: Orthodontic dental casts and cephalometric radiographs of 124 patients were investigated and analyzed. The dental casts were classified in relation to the molar relationship according to Angle's classification and to the incisal relationship according to the British Standards Institution (BSI) classification. The sagittal relation in the cephalometric radiographs was analyzed according to ANB angle and WITS appraisal. RESULTS: The results show that the incisal relation had a very high significant association with WITS appraisal (p = 0.0045), whereas with ANB, the association was marginally significant (p =0.0528). No significant associations were found with molar relation neither at ANB (p = 0.2075) nor at the WITS (p = 0.4794) appraisal. Significant positive correlations between ANB and WITS appraisal were found at the three incisal classification classes (class I, r = 0.73; class II, r = 0.64; class III, r = 0.75) and no significant correlation was observed in all classes with the Angle's (molar) classification. CONCLUSIONS: The incisal classification had a significant association with WITS appraisal, whereas with ANB the association was marginally significant. No correlation was found between Angle's (molar) classification and ANB or WITS appraisal. CLINICAL SIGNIFICANCE: The incisal relation could be considered as a good indicator of the skeletal malocclusion in the sagittal plane in the orthodontic practice.

Quality of cellular attachment to various root-end filling materials.

OBJECTIVES: This study investigated cellular attachment to 6 root-end filling materials as a measure of the biocompatibility of the materials. MATERIAL AND METHODS: Class I retrograde cavities were prepared in root slices and these cavities were filled with the test materials, and incubated with Balb/C 3T3 fibroblasts for 24 h. Root slices with the cavities left empty served as the controls. The root slices were then processed for scanning electron microscopy, and were viewed to assess the quality of cellular attachment by observing the shape of cells, spread, and membrane outline. RESULTS: The best cellular attachment was observed at MTA and Geristore surfaces: cells exhibited characteristic elongated fibroblastic morphology, with projections of lamellipodia, filopodia, blebs, and microvilli from their surfaces, reflecting good attachment to the material. Fibroblasts attached poorly to the surfaces of IRM, Super EBA, KetacFil and Retroplast. Furthermore, the cells did not attach well to the tooth structure next to IRM and Super EBA. CONCLUSIONS: The present study demonstrated a variation in cellular attachment to different root-end filling materials with the best cellular attachment to the surfaces of MTA and Geristore. IRM and Super EBA, KetacFil and Retroplast rendered poor attachment.

Quality of cellular attachment to various root-end filling materials

OBJECTIVES: This study investigated cellular attachment to 6 root-end filling materials as a measure of the biocompatibility of the materials. MATERIAL AND METHODS: Class I retrograde cavities were prepared in root slices and these cavities were filled with the test materials, and incubated with Balb/C 3T3 fibroblasts for 24 h. Root slices with the cavities left empty served as the controls. The root slices were then processed for scanning electron microscopy, and were viewed to assess the quality of cellular attachment by observing the shape of cells, spread, and membrane outline. RESULTS: The best cellular attachment was observed at MTA and Geristore surfaces: cells exhibited characteristic elongated fibroblastic morphology, with projections of lamellipodia, filopodia, blebs, and microvilli from their surfaces, reflecting good attachment to the material. Fibroblasts attached poorly to the surfaces of IRM, Super EBA, KetacFil and Retroplast. Furthermore, the cells did not attach well to the tooth structure next to IRM and Super EBA. CONCLUSIONS: The present study demonstrated a variation in cellular attachment to different root-end filling materials with the best cellular attachment to the surfaces of MTA and Geristore. IRM and Super EBA, Ketac Fil and Retroplast rendered poor attachment.

Toxicity testing of restorative dental materials using brine shrimp larvae (Artemia salina).

This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability) followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001). Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (alpha =0.05) showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100% lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001). Follow-up comparison between the groups by Tukey's test (alpha = 0.05) showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.

The effects of six root-end filling materials and their leachable components on cell viability.

This study investigated the effect of six root-end filling materials (Retroplast [Retroplast Trading, Dybesøvej, Denmark], Geristore, [DEN-MAT Corporation, Santa Maria, CA], Ketac Fil [3M ESPE, Seefeld, Germany], IRM [Caulk-Dentsply, Milford, DE], Super EBA [Bosworth Company, Skokie, IL], and MTA [Dentsply-Tulsa Dental, Johnson City, TN]) on the viability of Balb/C 3T3 fibroblasts using the [3-4, 5-dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide succinate (MTT) assay. Ten discs (5 mm x 2 mm) of each material were eluted in tissue culture medium for 24 hours at 37 degrees C for 3 successive days and the elutes used for cell viability testing and for determination of leached components. The results showed that Retroplast, Geristore, and Ketac Fil increased cell proliferation, whereas Super-EBA decreased cell viability. The proliferative effect of Retroplast and Geristore increased with the eluting time (24 hours, 48 hours, and 72 hours), whereas the effects of the other materials did not significantly change. IRM and MTA did not affect cell viability. High-performance liquid chromatography analysis and atomic absorption spectroscopy showed that there was variation in the amount of leached components from the materials. Our results indicate that the reaction of cells to root-end filling materials varies considerably between materials.

Toxicity Testing of Restorative Dental Materials Using Brine Shrimp Larvae (Artemia salina)

This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88 percent viability) followed by the extracts of Solitaire 2, Z100 and P60 (75 percent, 67.5 percent and 50 percent viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001). Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (á =0.05) showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100 percent lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3 percent, and 37.0 percent, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001). Follow-up comparison between the groups by Tukey's test (á = 0.05) showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.

Cytotoxicity of dental composites and their leached components.

OBJECTIVES: To investigate the toxicity of 4 types of resin-based dental composites with different compositions and to determine the components released from them using high-performance liquid chromatography (HPLC). METHOD AND MATERIALS: Resin composite disks (Z100, Solitaire 2, Filtek P60, and Synergy) were prepared, and cytotoxicity was tested on Balb/C 3T3 fibroblasts. In the first part of the study, cells were exposed to the composites for 72 hours (direct method), and in the second part to ethanolic extracts of the composites for 24 hours (indirect method), both at 37 degrees C. Cell viability was then determined by the MTT (3[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) method. RESULTS: The dental composites and their ethanolic extracts had adverse effects on the viability of Balb/C 3T3 fibroblasts. ANOVA revealed highly significant differences in cytotoxicity between the groups (P <.001) for both the direct and indirect methods. Follow-up comparison by Tukey test (alpha = .05) showed that Synergy was significantly less toxic than the other resin composites and Solitaire 2 was significantly more cytotoxic when the materials were tested by the direct method. However, using the indirect method, the extract of Synergy was significantly more toxic than all the other extracts. Bis-GMA, TEGDMA, UDMA, bis-EMA, and bisphenol A were detected by HPLC analysis; however, their presence and concentrations varied from one composite to another. CONCLUSIONS: The cytotoxicity level of resin-based dental composites depends on their chemical composition, leaching medium, and the amount and type of the components that can be extracted from the materials.

The radiographic outcomes of direct pulp-capping procedures performed by dental students: a retrospective study.

BACKGROUND: The decision between pulp capping and root canal therapy after pulp exposure is a clinical issue. The aim of the authors' study was to evaluate the outcome of direct pulp-capping procedures performed by dental students. METHODS: The authors followed the treatment outcomes of 193 patients with 204 pulp exposures with direct pulp capping. They determined the outcome of pulp capping radiographically using periapical radiographs taken at least three years after pulp exposure. The outcome was considered as successful if the tooth was present and not associated with periapical radiolucency or root canal treatment; otherwise, the outcome was considered as being a failure. RESULTS: Overall, the success rate of pulp capping was 59.3 percent. The success was associated more with mechanical exposure than with carious exposure (92.2 versus 33.3 percent) (P < .001), more with permanent restoration than with temporary restoration (80.8 versus 47.3 percent) (P < .001) and more with class I occlusal restoration (83.8 percent) than with proximal multiple surface restorations (Class II, 56.1 percent; Class III, 58.8 percent; mesial-occlusal-distal, 28.6 percent) (P = .009). Patients' age, sex, and tooth location and position had no significant effect on the outcome (P > .05). CONCLUSION: The success rate of direct pulp capping was 92.2 percent with mechanical exposure and 33.3 percent with carious exposure. CLINICAL IMPLICATIONS: Direct pulp capping is recommended after mechanical exposure with immediate placement of permanent restoration, while root canal therapy would be the choice of treatment if the exposure was due to caries.

Tooth wear among psychiatric patients: prevalence, distribution, and associated factors.

PURPOSE: The purpose of this study was to evaluate the prevalence, distribution, and associated factors of tooth wear among psychiatric patients. MATERIALS AND METHODS: Tooth wear was evaluated using the tooth wear index with scores ranging from 0 to 4. The presence of predisposing factors was recorded in 143 psychiatric patients attending the outpatient clinic at the Prince Rashed Hospital in northern Jordan. RESULTS: The prevalence of a tooth wear score of 3 in at least one tooth was 90.9%. Patients in the age group 16 to 25 had the lowest prevalence (78.6%) of tooth wear. Increasing age was found to be a significant risk factor for the prevalence of tooth wear (P < .005). The occlusal/incisal surfaces were the most affected by wear, with mandibular teeth being more affected than maxillary teeth, followed by the palatal surface of the maxillary anterior teeth and then the buccal/labial surface of the mandibular teeth. The factors found to be associated with tooth wear were age, retirement and unemployment, masseter muscle pain, depression, and anxiety. CONCLUSION: Patients' psychiatric condition and prescribed medication may be considered factors that influence tooth wear.