Intact Human Teeth Research Articles

Evaluation of effect of various drinks on tooth surface morphology under scanning electron microscope.

The study aimed to evaluate and compare the effect of various beverages carbonated drinks, i.e., thumps up, fresh fruit juice (apple and pomegranate) and packaged fruit juice (apple and pomegranate) on tooth surface morphology under scanning electron microscope. Thirty recently extracted intact caries-free human permanent teeth were disinfected with 5.25% of sodium hypochlorite solution and autoclaved at 240°F, 20 psi pressure for 40 min. Each tooth was sectioned into 4 enamel sections yielding 120 sections which were embedded in resin using a prefabricated mold. Prepared samples were immersed as Group I - thumps up, Group II - fresh apple juice, Group III - packaged apple juice, Group IV - fresh pomegranate juice, Group V - packaged pomegranate juice, and Group VI - normal saline. Each immersion was done daily for 30 min over 14 days after which samples were scanned under scanning electron microscope (SEM). The data obtained were subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS Version 23; Chicago Inc., IL, USA). The highest surface roughness was noted in the fresh pomegranate and packaged pomegranate groups with a mean of 2.9000 ± 0.30779 followed by thumbs up group. The greatest mean of cracks was noted in thumbs up group with a mean of 2.500 ± 0.51299 which was significant at P = 0.000. The greatest mean of score was noted in thumbs up group with a mean of 2.3000 ± 0.65695 which was significant at P = 0.000. The present study demonstrated that all drinks were erosive in nature with thumps and pomegranate juice showing significantly higher erosiveness than apple juice (P < 0.01).

A comparative evaluation of fracture resistance of three recent composite systems in Class II mesio occluso distal cavities - An in vitro study

Though composite resins have received popularity as restorative materials because of their physical properties, there was a dearth in the research about fracture resistance among recently emerged composite systems including Tokuyama Estelite Sigma Quick, Admira Fusion, and Beautifil II LS nanohybrid composite systems. To compare and evaluate the fracture resistance of maxillary premolars with class II mesio occluso distal cavities restored with Tokuyama Estelite Sigma Quick, Admira Fusion, and Beautifil II LS nanohybrid composite systems. Current invitro research was conducted on 44 intact human premolar teeth- Eleven specimens were kept completely intact for control group (Group G1). Class II MOD cavities were done with high-speed handpiece and under constant irrigation in remaining 33 teeth, Group G2, Group G3, Group G4 were restored with Tokuyama Estelite Sigma Quick (Tokuyama Dental, Tokyo, Japan.), Beautifil II LS (Shofu, Germany.), Admira Fusion (Shofu, Germany.) respectively. SPSS version 20 software to analyse the data; and ANOVA followed by Tukey’s post-hoc analysis to compare the fracture resistance were used. With a fracture resistance of 1297.27±10.27 N, Group 1 (Control) had highest fracture resistance. Group 4 has the least fracture resistance (Admira Fusion). Every pairwise comparison was significant too. Among the three materials studied, Beautifil II LS had higher fracture resistance and Admira Fusion had the least fracture resistance.

In-vitro evaluation of fracture resistance of teeth restored with different high-viscosity glass ionomer restorative materials and bulk-fill composite resins

ObjectivesThis study aimed to evaluate the effect of restorations made with a glass-hybrid restorative system (GHRS), a high-viscosity glass ionomer restorative material (HVGIC), a high-viscosity bulk-fill composite resin (HVB), a flowable bulk-fill composite resin (FB), and a nanohybrid composite resin (NH), which are commonly preferred in clinical applications on the fracture resistance of teeth in-vitro.Materials and methodsOne hundred intact human premolar teeth were included in the study. The teeth were randomly divided into ten groups (n = 10). No treatment was applied to the teeth in Control group. Class II cavities were prepared on the mesial surfaces of the remaining ninety teeth in other groups. For restoration of the teeth, a GHRS, a HVGIC, a HVB, a FB, and a NH were used. Additionally, in four groups, teeth were restored using NH, GHRS, and HVGIC with open and closed-sandwich techniques. After 24 h, fracture resistance testing was performed. One-way ANOVA and Tukey HDS tests were used for statistical analysis of the data.ResultsThe fracture resistance values of Control group were statistically significantly higher than those of GHRS, HVGIC, FB, NH, HVGIC-CS, GHRS-OS, and HVGIC-OS groups(p < 0.05). There was no statistically significant difference observed between the fracture resistance values of Control, HVB, and GHRS-CS groups (p > 0.05).ConclusionIt can be concluded that the use of HVB and the application of GHRS with a closed-sandwich technique may have a positive effect on the fracture resistance of teeth in the restoration of wide Class II cavities.Clinical relevanceThe use of high-viscosity bulk-fill composite resin and the application of glass-hybrid restorative system with the closed-sandwich technique in the restoration of teeth with wide Class II cavities could increase the fracture resistance of the teeth.

Co-Influence of Restoration Bonding and Inlay Cavity Design on Fracture Load of Restored Tooth.

The aim of this study was to investigate the co-influence of indirect mesio- occlusal-distal (MOD) cavity geometry and inlay restoration bonding on quasi-static fracture load of the restored tooth. Forty-eight intact human molar teeth were selected and prepared for standardized edge-shaped or round-shaped MOD cavities. The resin composite (Cerasmart, GC) inlays were bonded with the state-of-the-art inlay bonding protocol or with intentionally deteriorated bonding using n-hexane-wax solution for preconditioning. Restored teeth were loaded along the long axis of the tooth. Ultimate fracture load was recorded, and the type of fracture was visually determined and classified. Statistical analysis of load values was performed by Kruskal-Wallis test. Round-shaped cavity design with bonded restoration presented the highest fracture load (1658N). Bonding had significant influence on the fracture load of roundshaped cavity design (p=0.0003), whereas cavity design had no influence when the bonding was deteriorated (p=0.8075). In the case of deteriorated bonding, either the inlay or tooth fractured separately whereas in the bonded inlays fractures were commonly found both in the tooth and inlay. According to this study, bonded inlay restoration increased fracture resistance, while cavity design had no statistical difference on fracture resistance of the restored tooth.

Effect of strontium fluorophosphate bioactive glass on color, microhardness and surface roughness of bleached enamel.

Undesirable effects of tooth bleaching can alter the biomechanical properties of enamel. To determine the influence of strontium fluorophosphate bioactive glass (Sr-FPG) on color, microhardness and surface roughness of enamel bleached with 35% hydrogen peroxide. The labial enamel of 36 extracted intact human anterior teeth were divided into 3 groups (n= 12), group 1 (HP): bleaching with 35% hydrogen peroxide only, group 2 (Sr-HP): bleaching with Sr-FPG incorporated 35% hydrogen peroxide and group 3 (HP-SrFPG): bleaching with 35% hydrogen peroxide followed by remineralization with Sr-FPG. Four consecutive eight-minute applications of the bleaching gel were done twice in all the groups. Color change (ΔE), microhardness and surface roughness were evaluated at baseline, post-bleaching and post-remineralization using spectrophotometer, Vickers hardness tester and profilometric analysis respectively. The mean ΔE among the groups was statistically similar (p> 0.05). Bleaching with HP significantly reduced microhardness (p< 0.05), whereas bleaching with Sr-HP and HP-SrFPG did not (p> 0.05). Post-bleaching microhardness in Sr-HP was significantly higher than HP-SrFPG (p< 0.05). An increased surface roughness was seen in Sr-HP bleached samples (p< 0.05). The addition of Sr-FPG to hydrogen peroxide significantly improved enamel microhardness than its use post-bleaching. An increase in surface roughness was seen post-bleaching with HP and Sr-HP.

Influence of Different Mouthwashes on the Efficacy of Fluoridated Dentifrices in Prevention of Enamel Erosion: An In Vitro Study.

The purpose of the current study was to evaluate the impact of three various mouthwashes on the effectiveness of fluoride dentifrices in preventing enamel erosion. A total of 120 sound intact human premolar teeth which were extracted for orthodontic treatment were selected for the study. A 3 × 3 mm window section was positioned in the middle of the coronal surface of the tooth in order to define the study area. Each sample was placed in a solution of 1% citric acid (pH 3.5) for 10 minutes in order to produce an eroded surface. All samples were divided into two main groups (60 samples each) as follows: Group A for sodium fluoride dentifrices and group B for stannous fluoride dentifrices, again it is subdivided into: CHX: Chlohex ADS®, EO: Listerine®, CPC: Colgate® Plax (20 samples in each subgroup). After that, samples underwent the pH cycling model for 5 days. Samples were examined for surface loss using a scanning electron microscope. In sodium fluoride dentifrices group, before intervention, the surface loss was 3.12 ± 1.03 in CHX group, 3.08 ± 1.20 in EO group, and 3.09 ± 0.96 in CPC group. After intervention, the less surface loss found with CHX group (2.18 ± 0.84), followed by CPC (2.34 ± 0.74) and EO group (2.46 ± 0.97). In stannous fluoride dentifrices group, before intervention, the surface loss in CHX group was 3.26 ± 1.19, in EO group, it was 3.18 ± 1.31, and in CPC group, it was 3.22 ± 1.06. After intervention, the less surface loss found with CHX: group (1.90 ± 0.54), followed by CPC (2.24 ± 0.28) and EO group (2.38 ± 0.20). The present study concluded that the fluoride dentifrices' preventive effects against tooth surface loss were unaffected by a different mouthwashes with varying compositions and major constituents. In terms of erosion, fluoridated toothpaste containing stannous fluoride was found to provide better surface loss protection than sodium fluoride. Primary prevention and the eradication of contributing causes are the greatest strategies for preventing erosion. Simultaneously, antibacterial agent in the mouthwashes may help in enhancing the effect of fluoride in the enamel, owing to their high affinity for teeth structures. Therefore, in addition to cause-related treatment, further efforts to reduce tooth tissue loss are also necessary.

Spectrophotometric Analysis of Color Stability Induced by Various Calcium Silicate Cements in Full Pulpotomy of Permanent Molars: Theracal PT, Biodentine, and ProRoot MTA

AimThe objective of this study was to assess the color stability induced by Theracal PT, Biodentine, and ProRoot MTA in teeth subjected to full pulpotomy, over a span of 6 months. Materials and MethodsThe study employed a total of 48 freshly extracted intact human third molar teeth. Samples were randomly assigned into four groups (n = 12). All teeth, with the exception of the control group, underwent endodontic access. All materials were mixed in accordance with the manufacturer's guidelines and applied at a thickness of 3 mm at the orifice level before they set. The study groups were negative control (was not prepared), positive control (ProRootMTA), Biodentine, and Theracal PT. Glass ionomer and composite resin material was applied to the cavities. The color measurements were performed using the VITA Easy Shade spectrophotometer. All measurements were repeated 3 times in the determined area on the middle buccal surface of the tooth at baseline that (T0); after access preparation and material placement and setting) and then subsequently at 7 (T1), 30 (T2), 90 (T3), and T4 (180) days later. Data were statistically analyzed by using Kruskal-Wallis H at a confidence level of 95% (P < .05). ResultsCompared with the negative control group, Biodentine and Theracal PT showed color stability (ΔE ≤ 3.7). The teeth treated with MTA showed clinically observable discoloration (ΔE ≥ 3.7) at T0, T1, T2, T3, and T4 intervals. At all-time intervals, the MTA group induced more discoloration than Biodentine and Theracal PT (P < .05). ConclusionsTheracal PT and Biodentine caused least discoloration compared to PMTA even 6 months after its application in teeth undergoing pulpotomy, thereby offering clinicians a reliable alternative for use in the esthetic zone.

The Effect Of Er,Cr:YSGG Laser Conditioning on Dentin Bond Strength and Nanoleakage of Universal Adhesive Systems: An In Vitro Study.

To investigate the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives. A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (µTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey's honestly significant difference, and chi-square tests. The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05). Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the µTBS and nanoleakage, likely by affecting the structure of the hybrid layer.

Transdentinal cytotoxicity of resin luting cements using the bovine and human dentin barrier

Based upon ethical questions and because of the difficulty of obtaining intact human teeth, researchers have used bovine teeth to assess the physical and mechanical properties of different dental materials. However, data from transdentinal cytotoxicity tests showing that the bovine dentin barrier is similar to the human dentin barrier is lacking. The purpose of this in vitro study was to evaluate whether the bovine dentin barrier produces similar results to those obtained when the human dentin barrier is used to assess the transdentinal cytotoxicity of resin luting cements. The number and diameter of dentinal tubules present in the human dentin barrier and bovine dentin barrier were evaluated and assessed with a t test (α=.05). After inserting the standardized dentin barriers into artificial pulp chambers, murine dental papilla-derived cells (MDPC-23) were seeded on the pulpal surface of the specimens, and the luting cements were applied to their occlusal surfaces. Then, the following groups were established for both human and bovine dentin barriers: no treatment (negative control); Single Bond Universal; RelyX Luting 2; RelyX U200; and RelyX Ultimate. After 24 hours, the viability (alamarBlue) and morphology (scanning electron microscopy) of the cells were evaluated with a 2-way analysis of variance and the Tukey honest significance test (α=.05). Dentinal tubules with larger diameters were observed in bovine dentin (P<.05), but the number of tubules was similar (P>.05). A reduction in viability and notable changes in the morphology of MDPC-23 cells occurred in the Single Bond Universal and RelyX Luting 2 groups in comparison with the negative control (P<.05). The RelyX U200 and RelyX Ultimate groups were statistically similar to the negative control (P>.05). No difference was found in cytotoxicity when the same luting cement was applied on human or bovine dentin barriers (P>.05). For transdentinal cytotoxicity tests of resin luting cements, the bovine dentin barrier proved similar results to the human dentin barrier.

Influence of voxel size and filter type on detecting vertical root fracture using cone-beam computed tomography.

Vertical root fractures (VRFs) can start at any level of the root and progress longitudinally to the coronal attachment. This study aimed to investigate the effects of different exposure parameters used when obtaining CBCT scans in detecting simulated VRFs. Hence, 80 intact human mandibular single-rooted pre-molar teeth without root fractures were included in the study. No statistically significant difference was found between the filters in terms of VRF detection in the group with the roots with only root canal filling (Groups 1 and 5); however, 100 voxels were found to be more successful in terms of VRF detection than other voxel sizes. Results of this study suggest that using lower voxel sizes leads to an accurate diagnosis of vertical root fracture, in addition, our results revealed that using AR filters did not improve the diagnostic accuracy in detecting VRFs.

Fracture Load of Mesio–Occluso–Distal Composite Restorations Performed with Different Reinforcement Techniques: An In Vitro Study

Mesio-occluso-distal (MOD) cavity preparations are often fragile due to the amount of tooth and carious structure removed. MOD cavities can often fracture if left unsupported. The study investigated the maximum fracture load of mesi-occluso-distal cavities restored using direct composite resin restorations with various reinforcement techniques. Seventy-two freshly extracted, intact human posterior teeth were disinfected, checked, and prepared according to predetermined standards for mesio-occluso-distal cavity design (MOD). The teeth were assigned randomly into six groups. The first group was the control group restored conventionally with a nanohybrid composite resin (Group I). The other five groups were restored with a nanohybrid composite resin reinforced with different techniques: the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and layered with a nanohybrid composite (Group II); the everX Posterior composite resin layered with a nanohybrid composite (Group III); polyethylene fibers called "Ribbond" placed on both axial walls and the floor of the cavity, and layered with a nanohybrid composite (Group IV); polyethylene fibers placed on both axial walls and the floor of the cavity, and layered with the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and nanohybrid composite (Group V); and polyethylene fibers placed on both axial walls and the floor of the cavity and layered with the everX posterior composite resin and nanohybrid composite (Group VI). All teeth were subjected to thermocycling to simulate the oral environment. The maximum load was measured using a universal testing machine. The highest maximum load was exhibited by Group III with the everX posterior composite resin, followed by Group IV, Group VI, Group I, Group II, and Group V. A statistically significant difference was demonstrated between groups (p = 0.0023). When adjusting for multiple comparisons, there were statistical differences specific to comparisons between Group III versus I, Group III versus II, Group IV versus II, and Group V versus III. Within the limitations of the current study, it can be concluded that a higher maximum load resistance can be achieved (statistically significant) when reinforcing nanohybrid composite resin MOD restorations with everX Posterior.

AN IN VITRO COMPARISION OF BOND STRENGTH OF PRECOATED AND UNCOATED BRACKETS USING SELF ETCHING PRIMER

Aim: To test the hypothesis that there is no significant difference in the shear bond strength and the adhesive remnant on the tooth after debonding between precoated and uncoated brackets using a self etching primer.Materials and Methods: Adhesive Pre Coated Plus brackets, Uncoated brackets, Transbond XT adhesive and Transbond Plus self etching primer (TPSEP) were used in this study. The brackets were bonded to intact human premolar teeth. All the samples were divided into two groups --Group 1 (Uncoated brackets + Transbond Self Etching Primer + Transbond XT) &amp; Group 2 (Adhesive Precoated Brackets + Transbond Self Etching Primer). Universal Testing Machine was used for calculating the shear bond strength of all samples. Image analysis equipment was used to measure the adhesive remnant on each tooth after debonding. Scanning Electron Microscope was used for this purpose.Results: Group 1 (Uncoated brackets + Transbond Self Etching Primer + Transbond XT) &amp; Group 2 (Adhesive Precoated Brackets + Transbond Self Etching Primer) had nearly equal mean shear bond strength which is 8.86 +2.14 Mpa for precoated while 9.08 + 2.76 Mpa for the uncoated group. Statistically both the groups have almost same shear bond strength and significant difference was absent. In percentage of adhesive remnant also statistical difference between group 1 &amp; group 2 was absent.Conclusion: There was no significant difference in the shear bond strength and the adhesive remnant on the tooth after debonding between precoated and uncoated brackets using a self etching primer.

Development of Electron Paramagnetic Resonance Magnet System for In Vivo Tooth Dosimetry

As part of a homebuilt continuous wave electron paramagnetic resonance (EPR) spectrometer operating at 1.2 GHz, a magnet system for in vivo tooth dosimetry was developed. The magnet was designed by adopting NdFeB permanent magnet (PM) for the main magnetic field generation. For each pole of the magnet, 32 cylindrical PMs were arranged in 2 axially aligned ring arrays. The pole gap was 18 cm, which was wide enough for a human head breadth. The measured magnetic field was compared with the magnetic field distribution calculated in a finite element method (FEM) simulation. EPR spectra of intact human teeth irradiated 5 and 30 Gy were measured for the performance test with the developed magnet system and spectrometer. The measured mean magnetic flux density was estimated to be 44.45 mT with homogeneity of 1,600 ppm in a 2 cm diameter of the spherical volume of the XY plane, which was comparable to the FEM simulation results. The sweep coefficient of the magnetic field sweep coil was 0.35 mT per Ampere in both the measurement and FEM simulation. With ±9 A current, the sweep range was 5.7 mT, which was sufficiently wide to measure the tooth radiation-induced signal (RIS) and reference material. The peak-to-peak amplitude of the measured modulation field was 0.38 mT at the center of the magnet. With the developed magnet fully integrated into an EPR system, the EPR spectra of 5 and 30 Gy irradiated teeth were successfully acquired. The developed magnet system showed sufficiently acceptable performance in terms of magnetic flux density and homogeneity. The EPR spectrum of tooth RIS could be measured ex vivo. The RIS of 5 and 30 Gy irradiated teeth was clearly distinguishable from intact human teeth.

An In Vitro Study Comparing the Antimicrobial Efficacy of 0.2% Chitosan, 3% Sodium Hypochlorite, 2% Chlorhexidine against Enterococcus faecalis, Alone and in Conjunction with Diode Laser.

The aim and objective of this study was to compare the antimicrobial efficacy of 0.2% chitosan, 3% sodium hypochlorite, 2% chlorhexidine against Enterococcus faecalis, alone and in conjunction with diode laser.Materials and methodsThe root canals of 72 extracted intact human single-rooted teeth with single canals were prepared, and E. faecalis was incubated in the root canals for 7 days. The teeth were then randomly divided into the following four experimental groups: group I: Saline, group II: 0.2% Chitosan, group III: 3% Sodium hypochlorite, and group IV: 2% Chlorhexidine. These groups were further subdivided into three groups: (1) 10 mL irrigant only, (2) 10 mL irrigant, dried and irradiation with diode laser, (3) Diode laser was used for activation of irrigant solution. Samples were obtained from subgroups in each group and checked for turbidity. The effect of each irrigant was evaluated by counting the number of colony-forming units observed on inoculation with samples taken from the irrigated canal on bile esculin azide agar. The data thus obtained was recorded and put to statistical analysis.ResultsSignificant reductions were noted in E. faecalis colony counts in all groups (p < 0.05). The greatest reduction in colony count (0%) was noted in group IV followed by group II. Also, samples disinfected with diode laser after root canal irrigation showed less number of colony-forming units per mL as compared to the samples irrigated with root canal solutions alone or diode laser alone.ConclusionChitosan has the capability for use as an accessory for disinfection of the root canal system. The application of an 810-nm diode laser by itself did not have the adequate antimicrobial activity to be used as an adjunct in root canal therapy. Irradiation with diode laser ought to be used in conjunction with the irrigant to gain maximum antibacterial effect against E. faecalis.How to cite this articleGoel P, Galhotra V, Makkar S, et al. An In-vitro Study Comparing the Antimicrobial Efficacy of 0.2% Chitosan, 3% Sodium Hypochlorite, 2% Chlorhexidine against Enterococcus faecalis, Alone and in Conjunction with Diode Laser. Int J Clin Pediatr Dent 2022;15(1):109-114.

Comparison of Dentinal Microleakage in Three Interim Dental Restorations: An In Vitro Study.

The aim of this study was to assess and compare the coronal microleakage of e-Temp (DiaDent, Korea), intermediate restorative material (IRM) (Dentsply, Sirona), and Systemp Inlay (Ivoclar Vivadent, Germany) temporary restorative materials used to seal the class I cavity preparations. In this in vitro experimental study, three temporary restorative materials were assessed for microleakage. A standardized class I access cavities (2 mm × 4 mm) were prepared in 30 freshly extracted intact human premolar teeth. Teeth were then divided randomly into three groups consisting of 10 samples each. Teeth were restored with e-Temp (n = 10), IRM (n = 10), and Systemp Inlay (n = 10), temporary restorations, and subjected to thermocycling 5000 times in a cold bath followed by a temperature of 55°C with a dwell time of 30 seconds. Teeth were painted with two layers of nail polish except for 1 mm around the restoration margin, soaked in 1% methylene blue dye solution (pH 7.4), and kept for 24 h. Sticky wax was used to seal the apical foramina. All the teeth were sectioned mesiodistally, and the specimens were examined for the amount of dye penetration (microleakage) through the restoration using Digital Microscope under 50× magnification. Data were analyzed using descriptive statistics, Mann-Whitney U, and Kruskal-Wallis tests. e-Temp showed 1 (10%) specimen with dye penetration up to 1 mm (Score 1). The specimens restored with IRM showed a 1 (10%) and 9 (90%) of scores for 1 and 3 dye penetration. However, 2 (20%) teeth restored with Systemp Inlay showed a dye penetration up to 3 mm or more (Score 3). A comparison of mean microleakage values of e-Temp (0.03 ± 0.10), IRM (2.69 ± 0.77), and Systemp Inlay (0.78 ± 1.64) showed a statistically significant difference (P < 0.001). IRM specimens showed significantly higher microleakage values than e-Temp and Systemp Inlay specimens (P < 0.05). All the temporary restorative materials tested in this in vitro experiment showed a certain extent of microleakage. The temporary restorative material e-Temp showed the least microleakage values followed by Systemp Inlay and IRM.

A Pilot Study on the Degree of Tooth Staining Caused by Pollen Water and Chlorhexidine: In Vitro Study

Background: Chlorhexidine oral rinse has been used as an adjuvant in the treatment of periodontal disease. However, there are drawbacks of using chlorhexidine i.e. tooth staining and other side effects, including allergy reaction. In light of the proven therapeutic properties of pollen water as well as its relatively cheap cost in the market, pollen water has a potential to be an effective alternative to chlorhexidine oral rinse. The aim of this study is to compare the degree of tooth staining influenced by water-based pollen mouthwash to the standard Chlorhexidine mouthwash using spectrophotometer. Materials and Methods: 24 specimens from extracted intact human teeth were soaked into the three different solutions, Chlorhexidine, Pollen water (date palm pollen water suspension), and normal water. Color measurements were carried out by a spectrophotometer devise and recorded at 5 different time intervals. Color change (∆E), Chroma (C*) and Hue (H*) were analyzed and compared among the three solutions. Results: Overall mean ∆E was similar in all groups, significant difference between all time points was found only in pollen water. The change in C* was higher in pollen water as compared to other solutions. There was a subtle increase in H* in the Chlorhexidine samples after week 3. The H* values in pollen water were stable, but a sudden decrease was observed in week 6. The difference in H* among the three solutions was significant after 3 weeks. Conclusion: Within the limitation of our study, it can be concluded that Pollen water stained teeth to a lesser extent than did chlorhexidine. It might be beneficial to use Pollen water as mouthwash however, further investigation is needed regarding the efficacy of plaque control.

The effect of dental restoration geometry and material properties on biomechanical behaviour of a treated molar tooth: A 3D finite element analysis

ObjectivesTo test the hypothesis that restoration of class II mesio-occlusal-distal (MOD) cavities can be strengthened through judicious choice of restoration geometry and material properties. MethodsAn intact extracted human maxillary molar tooth was digitized, segmented, reconstructed, and four 3D restored tooth models were developed with four different restoration geometries: one straight, one single-curved, and two double-curved. Stress analysis was conducted for representative loading using finite element analysis, and maximum principal stresses were determined at the dentine-enamel and restoration-enamel junctions. A range of restorative material elastic moduli (5–80 GPa) and Poisson's ratios (0.25–0.35) were studied. Vertical loads of 400 N were applied on occlusal points, while the roots of the molar teeth, below the crevices, were supported in all directions. All the materials were modelled as homogeneous, isotropic, and elastic. ResultsThe maximum principal stresses at the restoration-enamel junctions were strongly dependent on the MOD restoration geometries. Peak stresses occurred along the palatal surface of the restoration rather than the opposite buccal surface. Double-curved restorations showed the lowest peak stress at restoration-enamel junctions. Choice of the mechanical properties of restorative material in the range of 5–35 GPa further reduced stress concentrations on the enamel. SignificanceClass II MOD restorations may be stronger if designed with double-curved marginal geometries that can reduce stress concentrations. Designs with convex and concave geometries were particularly effective because they reduced stress concentrations dramatically. Results suggest that relatively minor changes to the geometry of a restoration can have a substantial effect on stress at the restoration-enamel junction and motivate future experimental analysis.

Evaluation of the Effect of Cavity Preparation Using Er,Cr:YSGG Laser on Microleakage of Class V Composite Restorations

Background: The application of laser in dentistry for medical purposes such as caries removal, preparation of restorative cavities, and dental surface treatment for more effective bonding of restorative materials to the tooth has been significant. The present experimental study aimed to evaluate the effect of cavity preparation on microleakage by using erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) lasers, and to compare it with the effect of bur on microleakage in class V composite restorations. Methods: In this experimental study, 20 intact human premolar teeth were randomly divided into 2 equal groups according to the cavity preparation technique: G1: laser cavity preparation (LCP) using a Er,Cr:YSGG laser (Bio Lase, USA), and G2: bur cavity preparation (BCP). Standard class V cavity was prepared on both lingual and buccal surfaces in two groups. The samples underwent thermocycling for 3000 times (5-55ºC) and were immersed in a methylene blue 2% solution for 24 hours. After buccolingual sectioning from the middle of the restoration, a stereomicroscope with 20 x magnification was used to measure the penetration rate of the dye and to determine the score for microleakage. Data were analyzed using SPSS (version 16) software and Mann-Whitney U test (α=5%). Results: According to the study results, the minimum and maximum microleakage values were observed in the occlusal and gingival margins, respectively, which were identically for both groups. Comparing two groups (BCP and LCP) revealed that there was no significant difference between them in terms of microleakage values at the occlusal and gingival margins (P&gt;0.05). Conclusions: It was concluded that cavity preparation using Er,cr:YSGG laser had microleakage values similar to those found with conventional cavity preparation (bur) method in class V composite restorations.

Sealing Ability of New Translucent Zirconia Crowns Made with Digital Workflow and Cemented with Different Types of Cement.

This article evaluated the sealing capacity of single crowns made of a new zirconia (Katana STML, Kuraray Noritake) when cemented with two different cement types and two different marginal preparation types. Forty intact human anterior teeth, extracted for periodontal reasons, were used. Each sample was prepared with two margin preparations: knife-edge (KE) on one half of the tooth and chamfer (CH) on the other half. Based on the type of cement used, abutments were randomly distributed into one of two groups: Group 1 used resin cement (Panavia V5, Kuraray Noritake), and Group 2 used reinforced glass-ionomer cement (FujiCEM 2, GC). A digital workflow was utilized for crown fabrication. After the cementing procedures, samples were processed, and microleakage and scanning electron microscopic observations were made. Microleakage varied significantly depending on the type of cement combination used. Group 1 samples showed less microleakage (medians: 0.76 for CH and 0.51 for KE in Group 1, and 4.1 and 3.45 for Group 2, respectively) than Group 2 specimens; the difference was statistically significant (P < .000). KE preparation showed less microleakage than CH, although no statistically significant differences were found (P < .0558). Under microscopic observations, some samples showed internal fractures within the zirconia material. KE and CH seal the margin of zirconia crowns similarly. The resin cement system ensured better adhesion than reinforced glass-ionomer cement.

Microleakage Evaluation in Class V Cavities Restored with Five Different Resin Composites: In vitro Dye Leakage Study.

PurposeRestorative materials and techniques have improved the clinical success of a variety of restorative procedures. Despite these new improvements, microleakage remains one of the leading causes of restoration failure and may lead to postoperative sensitivity, enamel microcracks, marginal staining, discoloration, recurrent caries, and deformation of teeth. This study evaluated microleakages of five recent resin composites in class V cavities.Materials and MethodsStandardized class V cavities were prepared on the labial surfaces of one hundred extracted intact and noncarious human permanent premolar teeth. The cavities were divided into five groups (n=20) according to the resin composite material. Groups: A1, A2, A3, A4 and A5 were restored with Omnichroma, Spectrum, Mosaic, Tetric N-Ceram and Harmonize, respectively. The teeth were stained with methylene blue and then sectioned, and the extent of dye penetration was examined under a stereomicroscope and scanning electron microscope (SEM) to evaluate microleakage. One-way ANOVA test was used to statistically analyze the data. Statistical Package for Social Sciences Computer Software (SPSS) version 15.0 was used.ResultsDye penetration was observed at the tooth-restoration interface in all the studied samples, with varying degrees of penetration. At the cervical margins of the cavities, no statistically significant difference in the microleakage scores was observed (P=0.16). At the cavity floor, no statistically significant difference in microleakage scores was observed (P=0.74). Omnichroma resin composite had the highest microleakage results.ConclusionNanohybrid resin composites showed less microleakage than other resin composites. Among all the groups, Omnichroma showed the highest microleakage at the cavity floor and at the cervical areas.Clinical SignificanceIn light of our findings, nanohybrid resin composites appear to be capable of reducing microleakage, and the results reported herein must be verified by additional clinical trials.