Sinus membrane thickness of healthy endodontically treated maxillary molars.

OBJECTIVE: The study aimed to investigate the sinus membrane thickness (SMT) adjacent to healthy endodontically-treated maxillary molars with or without protruded apical foramen into the sinus cavity using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Images of 207 non-smoker patients aged 18-40 were retrospectively analyzed, 140 were endodontically treated, and 136 were without endodontic treatment. Patients with any sinus pathology, teeth that have symptoms, or poor root filling were excluded. Study groups consisted of Group EM-I (endodontically treated and protruded apical foramen), Group EM-C (endodontically treated and contacted apical foramen), and similarly without endodontic treatment; Group M-I and Group M-C. SMT upon the mesial, distal, and palatal roots was measured. One-way ANOVA and Student's t-tests were performed. RESULTS: Group EM-I had the thickest sinus membrane compared to other groups (p = 0.013). SMT values were 2.37-2.60 mm in Group EM-I, and 1.34-1.58 mm in other groups. Thickening (> 2 mm) percentages were 33.45% in Group EM-I and between 4.25 and 8.25% in other groups. No statistical difference was detected between first and second molars and genders (p > 0.05). CONCLUSION: When the apical foramen protruded into the sinus cavity, the conventional root canal treatment caused a minimal (between 2.37 mm and 2.60 mm) sinus membrane thickening with a rate of 33.45% based upon CBCT examinations.

Comparison of cyclic fatigue resistance of four pediatric rotary file systems at body temperature: an in vitro study.

BACKGROUND: The aim of this study was to compare the cyclic fatigue resistance (CFR) of the newly developed pediatric nickel-titanium (NiTi) rotary file systems for root canal preparation of primary teeth. METHODS: Eighty pediatric NiTi rotary file systems files were used in this study, including 20 EasyInSmile X-Baby (25/0.04), 20 Scope miniScope (25/0.04), 20 EndoArt Pedo Gold (25/0.04), and 20 EndoArt Pedo Blue (25/0.04) files. Static CFR tests; performed on a custom-made stainless steel block with an inner diameter of 1.5 mm, an angle of curvature of 60° and a curved artificial canal with a radius of curvature of 5 mm. The test system was filled with distilled water and the temperature was kept constant at 35 ± 1 °C. The files were rotated in the simulated canal until fracture occurred. The number of cycles to failure (NCF) data was recorded, and all the fracture surfaces of the files were evaluated using scanning electron microscopy (SEM). One-way ANOVA and Tukey tests were used for statistical analysis of the data, and the significance level was set at p < 0.05. RESULTS: EndoArt Pedo Blue showed the highest NCF values (2668.10 ± 755.26), while the miniScope showed the lowest NCF values (453.65 ± 72.51), with a statistically significant difference between all the tested file systems (p < 0.05). There was no statistical difference in terms of fractured fragment lengths among all tested files (p > 0.05). CONCLUSION: The EndoArt Pedo Blue file system showed the best CFR performance among the four file systems specifically designed for primary teeth.

Veneer Ceramic to Y-TZP Bonding: Comparison of Different Surface Treatments.

PURPOSE: The purpose of this study was to evaluate the effects of various surface-treatment techniques for enhancing the bond strength between veneering ceramic and yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). MATERIALS AND METHODS: Pre-sintered Y-TZP specimens were divided into eight groups (n = 10) according to the surface-treatment technique used: (a) untreated (control); (b) air abrasion with aluminum oxide particles; (c) erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation at different energy intensities (1 to 6 W). All specimens were then sintered and veneered with veneering ceramic according to the manufacturer's instructions. The obtained zirconia-ceramic specimens were immersed in 37°C distilled water for 24 hours before a shear bond strength test using a universal testing device at a 1 mm/min crosshead speed. The average values were calculated. After debonding, the Y-TZP surfaces were examined under a stereomicroscope to determine their fracture pattern, and the surface topography was evaluated with scanning electron microscopy after surface treatments. RESULTS: The bond strength ranged from 13.24 to 20.54 MPa. All surface treatments increased the bond strength between the veneering ceramic and Y-TZP; however, the value for the 6 W irradiation group was significantly different from the values for other groups (p ˂ 0.05). CONCLUSIONS: The present study's findings showed that higher energy densities were needed for the laser irradiation to improve the bond strength between the veneering ceramic and zirconia. CLINICAL IMPLICATION: Y-TZP is commonly used as a core material in fixed restorations. The bond strength between zirconia and the veneering ceramic can be affected by various surface treatments.

Neurotoxicity of various root canal sealers on rat sciatic nerve: an electrophysiologic and histopathologic study.

OBJECTIVES: The aim of this study was to compare the neurotoxicity of various root canal sealers on rat sciatic nerve by electrophysiologic and histopathologic analyses. MATERIALS AND METHODS: A total of 40 male rats were randomly divided into five groups: Control, AH Plus, GuttaFlow, Sealapex and Smartpastebio. Sciatic nerves of the rats were uncovered using the surgical procedures, and the prepared sealers were then applied on nerves with a polyethylene tube vehicle for 15 days. Nerve potentials were recorded at initial exposure, 5, 30 and 120 min (early phase), and 15 days (late phase) by an electrophysiologic analysis system for all groups. The obtained measurements were then used to calculate the nerve conduction velocities (NCV). Subsequently, all rats were sacrificed, and their sciatic nerves were removed for histopathologic analysis. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests for intergroup variables and the Friedman and Wilcoxon test for intragroup variables. Statistical significance was set at P < 0.05. RESULTS: There was no significant difference between early and late phase results in the control group. This group showed little or no lasting damage to nerve tissue. All sealers decreased the NCV in the early phase time periods, but this decrease was only statistically significant in the AH Plus group at 120-min time period (P < 0.0125). During the late phase, the AH Plus and GuttaFlow groups almost reached initial NCV values, and it was lower than the initial values in the Sealapex and Smartpastebio groups. However, this decrease was not statistically significant. When intergroup comparisons were performed, statistically significant differences occurred at 30 min in the Sealapex group and 120 min in the AH Plus group compared with the control group (P < 0.0125). All sealers induced neurotoxicity as a result of degenerative and inflammatory responses of nerve tissue in histologic analysis. Histologic analysis revealed Sealapex and GuttaFlow to be the most and least neurotoxic, respectively. CONCLUSIONS: All tested root canal sealers exhibited a variable degree of neurotoxicity depending on their chemical compositions. CLINICAL RELEVANCE: Apical extrusion of endodontic filling materials may cause undesired consequences, such as inflammation and severe neurotoxic damage; therefore, extrusion factor plays an important role during the root canal treatment.

Effects of dentin surface treatments including Er,Cr:YSGG laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin.

OBJECTIVE: Intra-canal post systems are commonly used to restore root-filled teeth. Bond strengths of the posts can be affected by various surface treatments of the post or the dentin. The aim of this study was to evaluate the effects of dentin surface treatments including erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin. MATERIALS AND METHODS: Forty single-rooted human maxillary incisors were filled and post spaces were prepared. After these procedures, the specimens were divided randomly into four groups according to the dentin surface treatments, as follows: (i) untreated surface (control), (ii) 1W Er,Cr:YSGG laser application, (iii) 2W Er,Cr:YSGG laser application and (iv) 3W Er,Cr:YSGG laser application. Then the posts were cemented into the root canals using dual-cured resin cement. Bonded specimens were cut into 1-mm-thick slices and push-out tests were performed using a universal testing device. All specimens were loaded until fracture and the failure modes were evaluated with a stereomicroscope at 32× magnification. Representative specimens were analyzed by scanning electron microscopy. Data were analyzed using a one-way ANOVA, Tukey and Wilcoxon tests. RESULTS: The bond strength values ranged from 3.22-4.68 MPa. There were no statistically significant differences among the groups, regardless of the different levels. The coronal and middle levels of the post space had significantly higher bond strength values compared with the apical level (p < 0.05). CONCLUSION: Er,Cr:YSGG laser irradiation with different intensities did not increase the bond strength of the fiber posts to the root canal dentin walls.

Push-out bond strength of three calcium silicate cements to root canal dentine after two different irrigation regimes.

OBJECTIVES: The aim of this study was to compare the push-out bond strength of three calcium silicate cements to dentine after two different irrigation regimes. MATERIALS AND METHODS: One hundred eighty 2-mm-thick root sections were prepared. The sections were divided into three main groups (n = 60). In group A, the sections were immersed in 1 % NaOCl for 3 min. In group B, the sections were immersed in 17 % EDTA for 3 min followed by 1 % NaOCl for the same period of time. In group C (control group), no irrigation was applied to the sections. The samples from each group were divided into four subgroups (n = 15). In subgroups A1, B1 and C1, DiaRoot BioAggregate; in subgroups A2, B2 and C2, MTA-Angelus and in subgroups A3, B3 and C3, MM-MTA were mixed with hand-mixing. In subgroups A4, B4 and C4, MM-MTA was mixed with auto-mixing. The mixed cements were then placed into cavities with a carrier. The samples were submitted to the push-out test and were loaded. All the data were analysed with one-way analysis of variance and the Tukey HSD multiple comparisons (p < 0.05). RESULTS: There were no statistically significant differences between the irrigation regimes regardless of the used materials. The resistance to displacement in subgroup B4 was significantly greater than that presented by subgroups A3, B3 and C3 (p < 0.05) while not different than all other groups. CONCLUSIONS: Irrigation regimes had not affected the push-out bond strength of the calcium silicate cements. Also, strength of auto-mixed MM-MTA was similar to the other cements. CLINICAL RELEVANCE: The novel calcium silicate cements would be a potentially useful material in endodontic procedures with favourable properties.

3D analysis of D-RaCe and self-adjusting file in removing filling materials from curved root canals instrumented and filled with different techniques.

The aim of this study was to compare the efficacy of D-RaCe files and a self-adjusting file (SAF) system in removing filling material from curved root canals instrumented and filled with different techniques by using microcomputed tomography (micro-CT). The mesial roots of 20 extracted mandibular first molars were used. Root canals (mesiobuccal and mesiolingual) were instrumented with SAF or Revo-S. The canals were then filled with gutta-percha and AH Plus sealer using cold lateral compaction or thermoplasticized injectable techniques. The root fillings were first removed with D-RaCe (Step 1), followed by Step 2, in which a SAF system was used to remove the residual fillings in all groups. Micro-CT scans were used to measure the volume of residual filling after root canal filling, reinstrumentation with D-RaCe (Step 1), and reinstrumentation with SAF (Step 2). Data were analyzed using Wilcoxon and Kruskal-Wallis tests. There were no statistically significant differences between filling techniques in the canals instrumented with SAF (P = 0.292) and Revo-S (P = 0.306). The amount of remaining filling material was similar in all groups (P = 0.363); all of the instrumentation techniques left filling residue inside the canals. However, the additional use of SAF was more effective than using D-RaCe alone.

Bond strength of calcium silicate-based sealers to dentine dried with different techniques.

OBJECTIVE: To assess the influence of various canal-drying techniques on the push-out bond strength between radicular dentine and both MTA Fillapex and iRoot SP sealers. MATERIALS AND METHODS: Eighty extracted single-root teeth were instrumented with ProTaper Universal rotary instruments to a size F4. The teeth were randomly assigned to 1 of 4 groups as follows: group 1, excess fluid in the canals was removed using a Luer vacuum adapter; group 2, the canals were dried with a single paper point; group 3, the canals were dried with 3-5 paper points, and group 4, the canals were rinsed with 95% ethanol and then dried with 3-5 paper points. In each group, the specimens were subgrouped according to root canal sealer into either subgroup A (MTA Fillapex) or subgroup B (iRoot SP sealer). Horizontal sections (thickness 1 ± 0.1 mm) were obtained from each specimen and a push-out test was performed using a universal testing machine at a crosshead speed of 1 mm/min on root slices. Statistical analysis was done using the Kruskal-Wallis test and Dunn's test for pair-wise comparisons. p < 0.05 was considered statistically significant. RESULTS: Canals dried with only 1 paper point and obturated with the iRoot SP sealer (subgroup 2B) showed significantly higher bond strengths to the root canal wall compared to all other subgroups (p < 0.05), except for subgroup 1B (p > 0.05). CONCLUSIONS: The canal-drying technique influenced the adhesive bond strength between calcium silicate-based root canal sealers and the root canal wall.

Pulp tissue dissolution capacities of different irrigation agitation techniques in artificial internal resorption cavities.

Purpose: The aim of this in vitro study was to compare the organic tissue dissolution capacities of 3 different irrigation agitation techniques (IATs) in artificial internal root resorption cavities (IRCs). Materials and methods: Ninety freshly extracted maxillary human incisors were selected. After decoronation procedure, the roots were split longitudinally, and a standard IRC were prepared in the canals on each half of the roots. Then, the bovine pulp samples (~2,3 mg) were previously weighed and placed into the cavities. The root fragments were reassembled and cemented to create a circular IRC within the canal. Teeth samples were randomly divided into 6 groups (n=15); sodium chlorur (NaCl) and sonic irrigation (SI), sodium hypochlorite (NaOCl) and SI, NaCl and passive ultrasonic irrigation (PUI), NaOCl and PUI, NaCl and laser activated irrigation (LAI), NaOCl and LAI. After that, the teeth were decemented and the tissue samples inside the cavities were weighed again. The percentage of weight loss was calculated and statistically analyzed. Results: SI has significantly more successful results than PUI and LAI in groups which the irrigant was NaCl. There was also a significant difference between LAI and PUI in groups which the irrigant was NaOCl (Group 6 ˃ Group 4, p=0.003). There was no significant difference between LAI and SI with NaOCl. Conclusion: Complete dissolution of bovine pulp tissue from IRCs was not achieved by any tested techniques. However, the LAI with NaOCl was more effective than other IATs. In addition, there is no significant difference between the LAI and SI with NaOCl.

Shear bond strength of resin-modified glass ionomer cement bound to mineral trioxide aggregate after various disinfection protocols.

This study compared the effects of 3 different cavity disinfection protocols (CDP) on the shear bond strength (SBS) of resin-modified glass ionomer cement (RM-GIC) to mineral trioxide aggregate (MTA). One hundred eighty standard holes were prepared and filled with MTA. They then divided into 3 main groups based on the chosen time intervals (15 min, 24 h, and 72 h). Main groups were divided into 3 subgroups based on the CDP [chlorhexidine gluconate (CHX), ozone, laser, and control]. RM-GIC was applied on MTA after CDP for all groups. A universal testing device was then used for test and the data was statistically analysed. CHX showed significantly lower SBS values except ozone and laser than the control (p < 0.05). There were no statistically significant differences among the time intervals. As a result, CHX decreased the bond strength between the MTA and RM-GIC while ozone and laser had no negative effect.

Accuracy of different electronic apex locators in determination of minimum Root perforation diameter.

This study aims to evaluate the ability of Raypex 6, Propex Pixi, Dentaport ZX, Apex ID, Propex II and Dr.'s Finder NEO to detect minimum root canal perforation diameter. One hundred single-rooted, extracted human teeth were artificially perforated by 5 burs in different diameters (0.25-1.25 mm) in 5 mm above the apex. Twenty teeth were assigned to each group. The actual canal lengths (AL) were measured under stereomicroscope followed by a measurement of electronic canal length (EL) using each electronic apex locator (EAL). None of the EALs were able to detect the perforation at diameters of 0.50 and 0.25 mm. Although all EALs used in our study were unable to detect perforations at diameters of 0.5 mm and 0.25 mm, they were highly successful in the determination of simulated root perforations at diameters of 1.25, 1 and 0.75 mm.

Antibacterial activity and physical properties of conventional glass-ionomer cements containing chlorhexidine diacetate/cetrimide mixtures.

STATEMENT OF THE PROBLEM: Hand excavation instruments are not as efficient as that with rotary burs in atraumatic restorative treatment (ART). PURPOSE: To evaluate the antibacterial activity (ABA), microhardness numbers (VHN), and cumulative fluoride releasing (CFR) patterns of conventional GICs (Fuji IX (FX) and Ketac Molar (KM)) containing chlorhexidine diacetate/cetrimide mixtures (2.5%/2.5%) (AB). MATERIALS AND METHODS: The powders of ABs were added to powders of FX and KM selected as experimental groups (EXPs). FX and KM were assigned as controls (CNTs). ABA against S.mutans (MS) and L.casei (LB) were examined between 1-90 days. VHN were calculated after 24 hours and CFR patterns measured between 1-30 days. Analysis of variance was used for comparison (p<0.05) RESULTS: Differences were found between EXPs regarding MS levels at days 1, 7 and 60 as well as for LB at all time periods (p<0.05). VHN decreased in EXPs compared to CNTs (p<0.05), and no differences were found between EXPs (p>0.05). CFR patterns tended to decrease in EXPs compared to the CNTs, but no differences were found between EXPs (p>0.05) CLINICAL SIGNIFICANCE These mixtures could be recommended for ART procedures to provide beneficial antibacterial effects without seriously deteriorating the physical properties of selected GICs.

Evaluation of the shear bond strength of zirconia to a self-adhesive resin cement after different surface treatment.

OBJECTIVES: The aim of this study was to evaluate the SBS of pre-sintered and sintered zirconia to a selfadhesive resin cement after various treatment (air abrasion and the Nd:YAG laser irradiation at varying power levels -1 W, 2 W and 3 W). MATERIAL AND METHODS: Ninety-nine zirconia specimens were prepared and divided into 3 groups: control (with no surface treatment); and pre-sintered and sintered groups with surface treatment. Surface treatment was applied before sintering in the pre-sintered group and after sintering in the sintered group. After following all protocols, a resin cement was layered on the zirconia surface. Shear bond strength was measured using a universal testing machine. The results were subjected to the statistical analysis. The surface topography and phase transformation of zirconia were evaluated using the atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses after surface treatment. RESULTS: The laser irradiation (3 W, 1 W and 2 W) of the pre-sintered zirconia surface resulted in the highest SBS values (p < 0.001), while the lowest SBS values were obtained with airborne particle abrasion of the pre-sintered and sintered zirconia surfaces. CONCLUSIONS: Laser irradiation increased the SBS of pre-sintered zirconia to a resin cement. Surface treatment with air abrasion had a lesser effect on the SBS values.

Human pulp tissue dissolution ability of different extracts of Sapindus mukorossi: An in vitro study.

Objective: Due to the many negative properties of sodium hypochlorite used in current root canal treatment, interest in biocompatible natural agents is increasing day by day. The aim of this study was to evaluate whether various extract solutions of Sapindus mukorossi have dissolution effects on human pulp tissues. Methods: Primarily powder extracts were obtained by extracting fruit shells of S. mukorossi in different solvents (ethanol, methanol, buthanol and distilled water). The test solutions were prepared and randomly separated into six groups with 10 samples in each group: ethanol extract, methanol extract, butanol extract, distilled water extract of S. mukorossi, sodium hypochlorite (NaOCl) and the control group. Among these, S. mukorossi extracts were separated into two subgroups, depending on their concentration level (50 µg/mL and 100 µg/mL). The pulp tissues of freshly extracted human molars were used for dissolution test. The weights of the pulpal tissues were measured and recorded for two times after the samples were placed in the solutions. Statistical analysis for all descriptive statistics was performed using SPSS 22 (P < 0.05). Results: Our results showed that maximum percent yield of preparation was obtained in methanol extract of S. mukorossi. Among all of the groups, the best dissolution capacity was seen in the NaOCl group (positive control group). Among S. mukorossi groups, the best tissue solvent solution was found in SMM group at 50 µg/mL and SMB group at 100 µg/mL. Conclusion: The different extracts of S. mukorossi had a capacity to dissolve pulp tissue but this capacity was less than NaOCl. Therefore, further studies will enable the creation of a commercial solution for clinical use by increasing the effectiveness of S. mukorossi while combining it with other endodontic irrigation solutions.

Antibacterial activity of silver nanoparticles activated by photodynamic therapy in infected root canals.

BACKGROUND: Root canal disinfection includes mechanical, chemical and biological struggle against microorganisms (MOs). Photodynamic therapy (PDT) and nanoparticle (NP) agents may be proposed as an alternative for use against intracanal infections due to their ability to disrupt biofilm and prevent bacterial adhesion to dentin. The use of NP agents in combination with light/photosensitizer (PS) agents increases the efficiency of PDT in root canal disinfection. OBJECTIVES: The aim of the study was to evaluate the effect of light application - PDT - on the antibacterial activity of the combination of a PS agent (toluidine blue O -TBO) and an NP agent (silver nanoparticles - AgNPs) for the disinfection of the root canals inoculated with Enterococcus faecalis (E. faecalis). MATERIAL AND METHODS: In this study, concentrations of 20 ppm of TBO and 10 ppm of AgNPs, which showed the highest antibacterial activity against E. faecalis in the TBO/AgNPs combination, were used according to the preliminary studies. After instrumentation, 120 human, single-rooted, straight-canal mandibular premolars of a standard length of 13 mm were contaminated with bacteria, and experimental procedures were conducted against 21-day-old mature biofilm. The teeth were randomly divided into 5 main experimental groups: TBO/light; AgNPs; TBO/AgNPs; AgNPs/light; and TBO/AgNPs/light. Then, these main groups were divided into 2 subgroups each, according to the 2 application time periods (30 s and 60 s) (n = 10). The remaining 20 teeth constituted positive and negative control groups. The data was analyzed with the Kolmogorov-Smirnov test, one-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD) test, and the Bonferroni correction. RESULTS: The NaOCl group provided a bacterial reduction that was higher than in all other groups in a statistically significant manner. Light application on the TBO/AgNPs combination was the group that provided the highest bacterial reduction after NaOCl. CONCLUSIONS: The photoactivation of the TBO/AgNPs combination led to an increase in the effect of PDT, and it has the potential to be used as an adjunct for disinfection of the root canal system.

Antibacterial activity and physical properties of glass-ionomer cements containing antibiotics.

This study evaluated the antibacterial effects, physical properties and bonding strengths of conventional glass-ionomer cements (GICs) containing antibiotics and determined the optimal concentration of antibiotics addition for use with the ART approach. Fuji IX GIC was used as a control. Three antibiotic mixtures, ciprofloxacin, metronidazole and minocycline, were added to powdered GIC (Fuji IX) to obtain concentration ratios of 1.5, 3.0 and 4.5% w/w. The antibacterial activity of each GIC was evaluated against Streptococcus mutans or Lactobacillus casei using agar-diffusion methods. The release of antibiotics was analyzed by high-performance liquid chromatography (HPLC). The compressive strength and bonding strength to dentin were measured and compared with those of control samples. The results were analyzed using the Mann-Whitney test and Wilcoxon test. All tested groups showed a significantly greater inhibition with growth of the selected bacteria in comparison to the control groups (p < 0.01). However, the 3% and 4.5% concentration ratios of antibiotics had significantly lower compressive strength and lower bond strength to dentin than the control group (p = 0.003). The GIC-containing antibiotics were effective in inhibiting S Mutans and L Casei. The addition of a 1.5% antibiotic mixture was optimal to giving appropriate physical and bonding properties.

Evaluation of apical filling after root canal filling by 2 different techniques.

OBJECTIVE: To determine the percent gutta-percha-filled area in the apical third of root canals after filling with 2 different root filling techniques. MATERIALS AND METHODS: Thirty extracted human lower premolars were instrumented with ProTaper rotary files (Dentsply Maillefer) and then randomly divided into 2 groups of 15 teeth each. The first group was filled using the single-cone technique with a tapered gutta-percha cone. The second group was filled with the lateral condensation technique. Horizontal sections were cut 2 and 4 mm from the apical foramen of each tooth. Photomicrographs of the apical surface of each cross-section were obtained at magnification x40. Digital image analysis was used to measure the overall area of the canal and the aggregate area occupied by gutta-percha; from these values, the percent gutta-percha-filled area was calculated. The data were compared by t test. RESULTS: The single-cone technique produced significantly greater percent gutta-percha filled area at 2 mm from the apex (p = 0.046), but there was no significant difference between the techniques at 4 mm from the apex (p = 0.17). CONCLUSIONS: These results suggest that the single-cone technique with tapered gutta-percha cones may yield better filling (measured as the percent gutta-percha-filled area) than the lateral condensation technique, at a level 2 mm from the apex.

Cytotoxicity analysis of strontium ranelate on cultured human periodontal ligament fibroblasts: a preliminary report.

BACKGROUND/PURPOSE: The aim of this study was to analyze the cytotoxicity of strontium ranelate (SR) on human periodontal ligament fibroblasts (PDL cells) in vitro. METHODS: PDL cells were obtained from healthy human third molars and cultured in Dulbeccos Modified Eagles Medium. The experimental groups were: G1, cultures treated with fresh medium (control); and G2, G3, G4 and G5: treated with SR at 20, 10, 5 and 2.5 mg/mL, respectively. The experimental times were 1, 6, 12 and 24 hours (short-term) for viability, and 2, 4, 6 and 8 days (long-term) for cell survival. The cells were counted using a hemocytometer. Data were then analyzed by one-way ANOVA and Tukey's tests (p < 0.05). RESULTS: Cultures treated with the highest SR concentrations (G2 and G3) had significantly lower cell viability and cell numbers (p < 0.05) than those in G1, G4 and G5. SR at 2.5 mg/mL was non-cytotoxic to PDL cells. CONCLUSION: SR was non-toxic at appropriate concentrations. Preclinical tests are needed to further assess its safety and effectiveness for tooth resorption prior to clinical use.

Influence of storage media containing Salvia officinalis on survival of periodontal ligament cells.

AIM: The purpose of this study was to determine the ability of Salvia officinalis (S. officinalis) extracts to serve as a storage medium for the maintenance of periodontal ligament (PDL) cell viability of avulsed teeth. METHODS AND MATERIALS: PDL cells were obtained from healthy third molars and cultured in Dulbecco's Modi?ed Eagle's Medium (DMEM). Cultures were subjected to 4, 2.5, 1.5, and 0.5% S. officinalis solutions, Hank's balanced salt solution (HBSS), phosphate buffered saline (PBS), and tap water. Tissue culture plates were incubated with experimental media at 37 masculineC for 1, 3, 6, 12 or 24 hours. PDL cell viability was assessed by trypan blue exclusion. Statistical analysis of the data was performed by one-way analysis of variance (ANOVA) complemented by the Tukey's test. The level of significance was 5% (p< 0.05). RESULTS: The results showed 2.5% S. officinalis was a more effective storage medium than the other experimental solutions (p<0.05). Only at 1 hour and 3 hours was there found similar effect between 2.5% S. officinalis and HBSS. At 24 hours, 2.5% S. officinalis was found to be significantly better than the other solutions tested. CONCLUSION: S. officinalis can be recommended as a suitable transport medium for avulsed teeth. CLINICAL SIGNIFICANCE: The findings of this study support the use of S. officinalis as another option for clinicians to use to store and transport avulsed teeth until reimplantation procedures can be done.

Nonsurgical endodontic treatment of dens invaginatus in a mandibular premolar with large periradicular lesion: a case report.

This case report describes the treatment of a dens invaginatus in a mandibular premolar with large periradicular lesion. A nonsurgical endodontic treatment was performed to tooth #28. During the treatment procedure, calcium hydroxide and a triple antibiotic paste were separately used for intracanal dressing. The apical third of the canal was obturated with mineral trioxide aggregate (MTA), and the remaining canal space was obturated with gutta-percha and AH 26 root canal sealer, using a lateral condensation technique. At follow-up examination after 1 year, the tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic surgical intervention.