Assessment of sealing efficacy, radiopacity, and surface topography of a bioinspired polymer for perforation repair.

Background: Root perforation repair presents a significant challenge in dentistry due to inherent limitations of existing materials. This study explored the potential of a novel polydopamine-based composite as a root repair material by evaluating its sealing efficacy, radiopacity, and surface topography. Methods: Confocal microscopy assessed sealing ability, comparing the polydopamine-based composite to the gold standard, mineral trioxide aggregate (MTA). Radiopacity was evaluated using the aluminium step wedge technique conforming to ISO standards. Surface roughness analysis utilized atomic force microscopy (AFM), while field emission scanning electron microscopy (FESEM) visualized morphology. Results: The polydopamine-based composite exhibited significantly superior sealing efficacy compared to MTA (P < 0.001). Radiopacity reached 3 mm aluminium equivalent, exceeding minimum clinical requirements. AFM analysis revealed a smooth surface topography, and FESEM confirmed successful composite synthesis. Conclusion: This study demonstrates promising properties of the polydopamine-based composite for root perforation repair, including superior sealing efficacy, clinically relevant radiopacity, and smooth surface topography. Further investigation is warranted to assess its clinical viability and potential translation to endodontic practice.

Assessment of the biointeractivity of a novel vital pulp therapy agent derived from eggshell biowaste: An in vitro study.

This study aimed to assess the calcium (Ca2+) and hydroxyl (OH-) ion-releasing ability, namely the biointeractivity of eggshell-derived hydroxyapatite (ESDHA) in comparison with mineral trioxide aggregate (MTA) and calcium hydroxide (CH). ESDHA, MTA and CH samples (n = 10; 8 × 1.6 mm) were immersed in 10 mL of deionised water (37°C, pH 6.8). Ca2+ and OH- ion releases were detected in 1, 7 and 21 days. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses were also conducted. IBM SPSS 20.0 was used for statistical analyses. The cumulative Ca2+ ions (56.22 ± 11.28 ppm) were detected as most significant in ESDHA (day 21; p < 0.05). The OH- ion values of the ESDHA group were statistically higher than MTA and CH (days 1 and 7; p < 0.05). ESDHA and CH showed a similar pattern with sharp peaks in Ca2+, oxygen and carbon elements. ESDHA being a sustainable material with a high ion-releasing ability may be a preferable alternative to the commercial vital pulp therapy agents.

Dental and composite resin discoloration induced by different hydraulic calcium silicate-based cements: two-year in vitro assessment.

Few long-term studies assess the discoloration induced by hydraulic calcium silicate-based cement on dental structures. In addition, as far as we know, no long-term study has assessed the discoloration induced by these cement on composite resin. This in vitro study aimed to assess, during a period of two years, the discoloration potential of different hydraulic calcium silicate-based cements (hCSCs) on the enamel/dentin structure and composite resin restoration. A total of 40 enamel/dentin discs were obtained from bovine incisors, and 40 composite resin discs (10 mm in diameter × 2 mm thick) were fabricated. A 0.8 mm-deep cavity was made in the center of each disc and filled with the following hCSCs (n=10): Original MTA (Angelus); MTA Repair HP (Angelus); NeoMTA Plus (Avalon); and Biodentine (Septodont). An initial color measurement was performed (T0 - baseline). After 7, 15, 30, 45, 90, 300 days, and two years, new color measurements were performed to determine the color (ΔE00), lightness (ΔL'), chroma (ΔC'), hue differences (ΔH'), and whiteness index (WID). For enamel/dentin, the ΔE00 was significant among groups and periods (p<0.05). NeoMTA Plus had the greatest ΔE00. The NeoMTA Plus group had the greatest ΔE00 after two years for composite resin. Significant reduction in lightness was observed for all groups after two years (p<0.05). The most significant WID values were observed after 30 days for Biodentine (enamel/dentin) and MTA Repair HP groups (composite resin) (p<0.05). The hCSCs changed the colorimetric behavior of both substrates, leading to greater darkening over time. The Bi2O3 in the Original MTA seems relevant in the short periods of color change assessment.

Assessment of bone quality of apical periodontitis treated with MTA plug and regenerative endodontic techniques.

Fractal analysis (FA) is a quantitative, objective and non-invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1-year follow-up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single-canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box-counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1-year follow-up (p < 0.01). However, there was no significant difference between the MTA plug and RET (p > 0.01). Significantly higher fractal dimension values were detected at 1-year follow-up in both MTA plug and RET cases (p < 0.01). However, the difference was not significant between the groups (p > 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity.

Partial pulpotomy without age restriction: a retrospective assessment of permanent teeth with carious pulp exposure.

OBJECTIVES: This study aimed to retrospectively evaluate clinical and radiographic outcomes of partial pulpotomy performed in permanent teeth with carious pulp exposure. MATERIALS AND METHODS: Records of patients undergoing treatment at an undergraduate dental clinic between 2010 and 2019 were screened for partial pulpotomies in teeth with a presumptive diagnosis of normal pulp or reversible pulpitis. The follow-up had to be ≥ 1 year. Patient data were retrieved and analyzed using Mantel-Cox chi square tests and Kaplan-Meier statistics. The level of significance was set at α = 0.05. RESULTS: Partial pulpotomy was performed in 111 cases, of which 64 (58%) fulfilled the eligibility criteria. At the time of partial pulpotomy, the mean age was 37.3 (± 13.5) years (age range 18-85). The mean observation period was 3.1 (± 2.0) years. Two early failures (3.1%) and five late failures (7.7%) were recorded. The overall success rate of maintaining pulp vitality was 89.1%, with 98.4% tooth survival. The cumulative pulp survival rates of partial pulpotomy in patients aged < 30 years, between 30 and 40 years, and > 40 years were 100%, 75.5%, and 90.5%, respectively, with no significant difference between the age groups (p = 0.225). At follow-up, narrowing of the pulp canal space and tooth discoloration were observed in 10.9% and 3.1% of cases, respectively. CONCLUSIONS: Across age groups, partial pulpotomy achieved favorable short and medium-term outcomes in teeth with carious pulp exposure. CLINICAL RELEVANCE: Adequate case selection provided, partial pulpotomy is a viable operative approach to treat permanent teeth with deep carious lesions irrespective of patients' age.

In Vitro Assessment of Sealing Ability of Various Materials Used for Repair of Furcal Perforation: A SEM Study.

AIM: The aim of the current in vitro research was to evaluate the sealing capacity of three different agents employed for the repair of perforations at the furcation area. MATERIALS AND METHODS: Recently 60 extracted human mandibular permanent molars having well apart plus fully formed roots, and intact furcation were chosen. The 60 samples were allocated at random to three groups of 20 samples: Group I: Furcation perforation repair by means of mineral trioxide aggregate (MTA)-Angelus, Group II: Furcal perforation repair using Biodentine, Group III: Furcal perforation repair by EndoSequence. The specimens were subjected to sectioning with a hard tissue microtome and the sectioned parts of the samples were then examined. The specimens were subjected to gold sputtering and visualizing beneath scanning electron microscope (SEM) at 2000× magnification for assessing the sealing capacity of the agents. RESULTS: The highest sealing capacity was noted with the use of Biodentine at 0.96 ± 0.10, in pursuit by EndoSequence use at 1.18 ± 0.14 and MTA-Angelus use at 1.74 ± 0.08. The disparity amid the three groups was statistically significant with p < 0.001. CONCLUSION: In conclusion, it may be inferred that Biodentine exhibited the finest sealing capacity than EndoSequence and MTA- Angelus. It may thus be given consideration as a substance of preference for the repair of furcal perforation. CLINICAL SIGNIFICANCE: Using biologically compatible substances may be suggested to amend perforations thereby decreasing the occurrence of inflammatory response in the neighboring tissues. The sealing capacity is a significant feature in supporting the result of a root canal treatment of a tooth.

Assessment of Clinical and Radiographic Success Rate of Formocresol-based Pulpotomy versus Collagen-based Pulpotomy: An In Vivo Study.

AIM: The aim of the study is (a) To use collagen as a pulpotomy material in comparison with the gold standard formocresol-based pulpotomy, (b) to assess the clinical and radiographic success rate of formocresol pulpotomy and collagen-based pulpotomy, and (c) to compare the success rate of formocresol-based pulpotomy and collagen-based pulpotomy over a definitive interval of time. MATERIALS AND METHODS: Totally 30 primary first or second molars indicated for pulpotomy after confirming with the operative diagnosis were taken as samples for this study. This split-mouth technique consists of two groups: Group 1-formocresol pulpotomy (n = 15), and group 2-collagen-based pulpotomy (n = 15). Both the procedures were done in the same patient on regular appointments. Pre- and postoperative radiographs were taken. The children were recalled for clinical and radiographic follow-up at 2, 4, and 6 months. The success of the procedure was assessed based on clinical signs (pain, tenderness to percussion, abscess, swelling, fistula, and pathologic mobility) and radiographic findings (radicular radiolucency, internal and external root resorption, periodontal ligament (PDL) space widening, and furcation radiolucency). The Chi-square test was used to compare the differences between the groups. RESULT: The overall success rate for formocresol pulpotomy (n = 15) was 14, 13, and 10 for the second-, fourth-, and sixth-month review period, respectively. For collagen pulpotomy group (n = 15), the overall success rate was 14, 14, and 14 for the second-, fourth-, and sixth-month review period, respectively. The obtained data from the overall success rate were subjected to statistical analysis, and chi-square test was used. The p-value less than 0.1 was considered a statistically significant result. The chi-square value for the fourth- and sixth-month review was 0.37 and 3.33, respectively. CONCLUSION: Statistically significant value was obtained from the sixth-month review period (p <0.1), which describes that the overall success rate was better for the collagen pulpotomy group when compared with the formocresol pulpotomy group. CLINICAL SIGNIFICANCE: Collagen had proven to be a very good alternative for formocresol, its biocompatibility, and regenerative efficiency and is a benchmark for a better clinical success rate in dentistry. However, its implication in pulpotomy should be subjected to further comparative research study on mineral trioxide aggregate (MTA), Biodentine, etc. Keywords: Collagen-based pulpotomy, Formocresol-based pulpotomy.

The Osteogenic Assessment of Mineral Trioxide Aggregate-based Endodontic Sealers in an Organotypic Ex Vivo Bone Development Model.

INTRODUCTION: Mineral trioxide aggregate (MTA)-based sealers are endodontic materials with widespread success in distinct clinical applications, potentially embracing direct contact with the bone tissue. Bone response to these materials has been traditionally addressed in vitro. Nonetheless, translational data are limited by the absence of native cell-to-cell and cell-to-matrix interactions that hinder the representativeness of the analysis. Ex vivo organotypic systems, relying on the culture of explanted biological tissues, preserve the cell/tissue composition, reproducing the spatial and organizational in situ complexity. This study was grounded on an innovative research approach, relying on the assessment of an ex vivo organotypic bone tissue culture system to address the osteogenic response to 3 distinct MTA-based sealers. METHODS: Embryonic chick femurs were isolated and grown ex vivo for 11 days in the presence of MTA Plus (Avalon Biomed Inc, Bradenton, FL), ProRoot MTA (Dentsply Tulsa Dental, Hohnson City, Germany), Biodentine (Septodont, Saint Maurdes Fosses, France), or AH Plus (Dentsply Sirona, Konstanz, Germany); the latter was used as a control material. Femurs were characterized by histologic, histochemical, and histomorphometric analysis. Gene expression assessment of relevant osteogenic markers was conducted by quantitative polymerase chain reaction. RESULTS: All MTA-based sealers presented an enhanced osteogenic performance compared with AH Plus. Histochemical and histomorphometric analyses support the increased activation of the osteogenic program by MTA-based sealers, with enhanced collagenous matrix deposition and tissue mineralization. Gene expression analysis supported the enhanced activation of the osteogenic program. Comparatively, ProRoot MTA induced the highest osteogenic functionality on the characterized femurs. CONCLUSIONS: MTA-based sealers enhanced the osteogenic activity within the assayed organotypic bone model, which was found to be a sensitive system for the assessment of osteogenic modulation mediated by endodontic sealers.

Tooth discoloration induced by the different phases of a calcium aluminate cement: One-year assessment.

OBJECTIVES: To assess the discoloration of teeth treated with the different phases of calcium aluminate cement (CAC), in comparison with the conventional CAC and mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Fifty bovine incisors were prepared and filled. Two millimeters of the filling was removed to fabricate a cervical plug with the following cements (n=10): CA(CaO.Al2 O3 ); CA2 (CaO.2Al2 O3 ); C12 A7 (12CaO.7Al2 O3 ); CAC and MTA. The initial color measurement was performed and after 7, 15, 30, 45, 90, 180, and 365 days new color measurements were performed to determine the color (ΔE00 ), lightness (ΔL'), chroma (ΔC'), hue differences (ΔH'), and the whiteness index (WID ). RESULTS: ΔE00 was significant for groups (p = 0.036) and periods (p < 0.05). The greater ΔE00 was observed after 365 days for CAC (12.8). C12 A7 (7.2) had the smallest ΔE00 . ΔL' and ΔC' were significant for groups and periods (p < 0.05). ΔH' was significant for periods (p < 0.05). After 365 days, significant reduction in lightness was observed for all groups. For CA, CA2 , CAC, and MTA groups, the WID values decreased over time (p < 0.05). CONCLUSIONS: The tested cements changed the color behavior of the samples, resulting in greater teeth darkening over time. CLINICAL SIGNIFICANCE: There is no long-term study assessing the discoloration induced by the different phases of CAC.

Assessment of marginal integrity of five different polymers in retrograde root-end filling following apicoectomy: An in-vitro analysis with scanning electron microscope and micro-radiography.

PURPOSE: The aim of the study was to evaluate marginal adaptation properties of five different sealers used as root filling material. MATERIALS: Apical resection was performed on 100 canals of 50 maxillary premolars in slaughtered pigs. The root end of 24 canals were retrogradely filled with Diaket™, 37 root canals with Super-EBA™ including 18 with Super-EBA™. Regular and 19 with Super-EBA™ fast, 20 canals with ProRoot® MTA and 19 canals with AH-Plus™. For quantitative examination, scanning electron microscope (SEM) analysis and for qualitative examination, microradiography was performed. RESULTS: Diaket™ achieved an overall average of 4.872 microns gap value as the best result. The mean values of marginal gap widths of AH-Plus™ and Super-EBA™ were almost with 8.044 microns and 9.951 microns in about the same magnitude, followed by Super-EBA™ Regular with 11,560 microns. Highest marginal gap value was found for ProRoot® MTA with 18.343 microns ( p < 0.001). CONCLUSIONS: Both in terms of its marginal integrity and material properties, Diaket™ is the most suitable material for retrograde obturation. A preliminary version of the current paper could be found at www.researchsquare.com/article/rs-6198/v1.

Maintaining pulpal vitality: Cost-effectiveness analysis on carious tissue removal and direct pulp capping.

OBJECTIVES: When managing deep carious lesions, dentists can maintain pulp vitality via (1) avoiding pulp exposure and complications by performing selective (SE) instead of non-selective (NS) carious tissue removal, and/or (2) treat exposed pulps by direct capping with mineral-trioxide-aggregate (MTA) instead of calcium hydroxide (CH). We assessed the cost-effectiveness of SE vs. NS combined with direct pulp capping using MTA vs. CH. METHODS: A mixed public-private-payer perspective within German healthcare was applied. We modeled a permanent molar with a deep carious lesion and a vital asymptomatic pulp. The lesion was treated by SE/NS and, in case of exposure, direct pulp capping using MTA/CH. The tooth was followed over the lifetime of an initially 30-year-old patient using Markov-models, informed by pairwise and Bayesian network meta-analyses and further data sources. The primary health outcome was tooth-retention time. Costs were derived from German fee item catalogues, combined with micro-costing. Monte-Carlo micro-simulation was performed, and uncertainty introduced via probabilistic and univariate sensitivity analyses. Value-of-information-analysis (VOI) was performed to quantify the value of further research. RESULTS: SE and, in case of pulp exposure, MTA had a high chance (>95 %) of being cost-effective, with teeth being retained for 37.37 years at costs of 2140 Euro in mean. Alternative strategies were both more costly and less effective; this ranking was robust in sensitivity analyses. The VOI was 1.18 Euro per treated case and 12.86 million Euro on population-level. CONCLUSION: Selective carious tissue removal and, in case of pulp exposure, direct capping with MTA was the most cost-effective strategy. CLINICAL SIGNIFICANCE: Avoiding pulp exposure was more relevant for cost-effectiveness than how the exposed pulp was managed. Overall differences remain limited, though, and dentists may want to tailor treatment strategies according to their expertise and patients' expectations.

Assessment of bone healing after mineral trioxide aggregate and platelet-rich fibrin application in periapical lesions using cone-beam computed tomographic imaging.

OBJECTIVES: The aim of this study was to compare the effects of mineral trioxide aggregate (MTA) and platelet-rich fibrin (PRF) use on periapical healing in surgically treated periapical lesions using three-dimensional (3D) cone-beam computed tomographic (CBCT) imaging. MATERIALS AND METHODS: A total of 40 periapical lesions undergoing apical surgery were selected between December 2016 and November 2017. The participants were randomly divided into four study groups: control, MTA, PRF, and MTA+PRF. No interventions were made in the control group except root-end resection. Routine radiographs were taken in the 3rd, 6th, and 12th months. The volume and density of periapical lesions at the 1-year follow-up were compared with the pre-op values using the MIMICS software program. Primary healing of the periapical tissues was evaluated, and the outcomes were noted. RESULTS: Post-op volume values were significantly decreased, and density values were significantly increased according to the pre-op measurements. In the post-op volume evaluation between the groups, significant differences were observed in the MTA and MTA+PRF groups compared with the control group (p < 0.005). However, no substantial significance was noted between the control and PRF groups. There were no significant differences in post-op density calculations between all groups. CONCLUSION AND CLINICAL RELEVANCE: High success rates were achieved using MTA in periapical lesions in endodontic microsurgery. The application of PRF to the surgical cavity may not necessarily improve outcomes. Further studies are needed with long-term follow-up. TRIAL REGISTRATION NUMBER: NCT03743987 (The Effect of MTA and PRF Application in Periapical Lesions).

Assessment of membrane bioreactor fouling with the addition of suspended aluminum nitride nanoparticles.

In this study, we assessed fouling in a membrane bioreactor (MBR) with the addition of suspended aluminum nitride (AlN) nanoparticles (NPs). Three parallel laboratory-scale submerged MBRs were operated with 0, 10, and 50 mg AlN NPs/L for over 70 days. The results showed that the addition of suspended AlN NPs did not significantly affect pollutant biodegradation; there was only a slight decrease in NH4+-N removal. Furthermore, the membrane's permeability was increased with effective fouling mitigation by the addition of a high amount of suspended AlN NPs. This was because the suspended AlN NPs decreased the content of polysaccharides in both the extracellular polymeric substances and soluble microbial products, and decreased the sludge floc size. However, the AlN NPs also promoted pore-blocking, particularly standard blocking, which enhanced irreversible fouling. Additionally, owing to the larger ionic radius and higher electronegativity, the AlN NPs inhibited the accumulation of framework components (SiO2). Therefore, suspended AlN NPs resulted in a thinner cake layer.

An assessment of vegetation management practices and burrow fumigation with aluminum phosphide as tools for managing voles within perennial crop fields in California, USA.

Voles (Cricetidae) cause extensive damage to a variety of crops throughout much of the Northern Hemisphere. The removal of vegetation from crop fields at the end of the growing season, combined with a subsequent burrow fumigant application of aluminum phosphide, has the potential to substantially curtail vole activity but has not been thoroughly examined. We set up a study to test the impact of these management tools in perennial globe artichoke (Cynara cardunculus var. scolymus) fields in Monterey County, CA, during 2010 and 2011, to determine their potential utility as part of an integrated pest management (IPM) program for managing California voles (Microtus californicus). We used both chewing indices and mortality estimates derived via radiotelemetry to assess the efficacy of aboveground vegetation removal and aluminum phosphide applications on vole abundance. We determined the impact of plowing artichoke fields on vole activity as well. Both removal of vegetation and applications of aluminum phosphide substantially reduced vole presence within treated fields. Plowing also reduced vole abundance to the point of little residual activity following treatment. These management practices appear to be effective at eliminating voles from crop fields. Combining these tools with management practices designed to slow down reinvasion by neighboring vole populations (e.g., barriers, repellents, traps) has the potential to substantially reduce farmer reliance on rodenticides for vole management, although rodenticides will still be needed to curtail populations that reestablish within crop fields. Such an IPM approach should substantially benefit both farmers and agro-ecosystems.

Iodine budget in forest soils: Influence of environmental conditions and soil physicochemical properties.

Due to its longevity, radioisotope 129I is a health concern following potential releases in the environment which raises questions about residence and exposure times relevant for risk assessments. We determined 127I concentrations (as a surrogate for 129I) in a series of French forest soils (i.e. litters, humus and mineral soils) under different vegetation and climate conditions in order to identify the major processes affecting its accumulation and persistence in the soil column. The input fluxes linked to rainfall, throughfall and litterfall were also characterized. Main results obtained showed that: (i) rainfall iodine concentrations probably influenced those of litterfall through absorption by leaves/needles returning to the ground; (ii) throughfall was the major iodine input to soils (mean = 83%), compared to litterfall (mean = 17%); (iii) humus represented a temporary storage of iodine from atmospheric and biomass deposits; (iv) iodine concentrations in soils depended on both the iodine inputs and the soil's ability to retain iodine due to its organic matter, total iron and aluminium concentrations; (v) these soil properties were the main factors influencing the accumulation of iodine in the soil column, resulting in residence times of 419-1756 years; and (vi) the leaching of iodine-containing organic matter dissolved in soil solution may be an important source of labile organic iodine for groundwater and streams.

Biocompatibility and biomineralization assessment of mineral trioxide aggregate flow.

OBJECTIVE: Evaluate, in vivo, the biocompatibility via subcutaneous inflammatory tissue response and mineralization ability of the new MTA Flow compared to MTA Angelus and ProRoot MTA. MATERIALS AND METHODS: Forty male Wistar rats were assigned and received subcutaneous polyethylene tube implants containing the test materials and a control group with empty tube (n = 10 animals/group). After days 7, 15, 30, and 60, the animals were euthanized and the polyethylene tubes were removed with the surrounding tissues. Inflammatory infiltrate and thickness of the fibrous capsule were histologically evaluated. Mineralization was analyzed by Von Kossa staining and under polarized light. Data were analyzed via Kruskal-Wallis and Dunn's test with a significance level of 5%. RESULTS: MTA Angelus induced the mildest reaction after 7 (P > .05) and 15 days (P < .05) followed by MTA Flow, both cements achieving mild inflammatory reaction after 15 days. ProRoot MTA induced a severe inflammation on day 7 and was reducing after day 15 (P > .05). No difference was observed after days 30 or 60 (P > .05). Von Kossa staining and birefringent structures were positive to all materials. CONCLUSIONS: At the end of the experiment, the novel MTA Flow showed biocompatibility and induced biomineralization in all time periods. CLINICAL RELEVANCE: The final consistence obtained in MTA Flow may facilitate several procedures, indicating that the MTA Flow has a promising application in endodontics.

Postoperative assessment of diode laser zinc oxide eugenol and mineral trioxide aggregate pulpotomy procedures in children: A comparative clinical study.

AIM: The present study is an attempt to compare and evaluate postoperative assessment of diode laser zinc oxide eugenol (ZOE) pulpotomy and diode laser mineral trioxide aggregate (MTA) pulpotomy procedures in children. MATERIALS AND METHODS: Forty carious primary molars indicated for pulpotomy within the age group of 4-9 years were selected and divided into two groups of 20 each using simple randomization, Group 1: Diode laser MTA and Group 2: Diode laser ZOE pulpotomy. The teeth were evaluated clinically for 1 year at 3, 6, and 12 months interval and radiologically for 6 and 12 months. RESULTS: Clinically and radiographically, 100% teeth treated with diode laser MTA and 94% treated with diode laser ZOE were considered successful after 12-month follow-up interval. No significant difference was seen between two groups. CONCLUSION: Despite the success rate, the cost factor of diode laser and MTA could be the limiting factor in its judicious use in pulpotomy procedure.

Cement AH Plus Adhesiveness Assessment Associated with Mineral Trioxide Aggregate in Different Proportions (Push-out Test).

AIM: The aim of the study is to evaluate the adhesiveness of the AH Plus plug cement, plus the mineral trioxide aggregate (MTA) in different proportions, through the push-out test. MATERIALS AND METHODS: The authors utilized fifty premolars with a single conduit, which were divided into five groups with 10 teeth. In group 1, the authors performed an obturation with AH Plus cement, group 2 was filled with AH Plus cement with 10% of MTA, group 3 was filled with AH Plus cement plus 20% MTA, group 4 was filled with AH Plus with 30% of MTA and group 5 filling was performed with the MTA Fillapex endodontic cement. The specimens were sectioned in 2 mm slices and submitted to the push-out test in a universal testing machine. The authors cataloged the data and follow through with statistical analysis based on T-test for independent samples, with a significance level of 5%. RESULTS: There was no statistical difference in group 2. Groups 3 and 4 presented better adhesion than AH Plus cement and MTA Fillapex. There was no statistical difference between the AH Plus cement and the MTA Fillapex. CONCLUSION: The authors concluded that the addition of MTA in the proportion of 10% to the AH Plus does not alter its adhesive property. They also observed that when the MTA increased by 20% and 30% there was an increase in the adhesiveness of the material when submitted to the push-out test. CLINICAL SIGNIFICANCE: The relevance of this study refers to the MTA inducing the deposition of mineralized tissue. However, it is necessary to compare it to the AH Plus cement considered "Gold Standard" in physical-chemical properties tests.

Assessment of coagulation pretreatment of leachate by response surface methodology.

Coagulation-flocculation is a relatively simple technique that can be used successfully for the treatment of old leachate by poly-aluminum chloride (PAC). The main objectives of this study are to design the experiments, build models and optimize the operating parameters, dosage m and pH, using the central composite design and response surface method. Developed for chemical organic matter (COD) and turbidity responses, the quadratic polynomial model is suitable for prediction within the range of simulated variables as it showed that the optimum conditions were m of 5.55 g/L at pH 7.05, with a determination coefficient R² at 99.33%, 99.92% and adjusted R² at 98.85% and 99.86% for both COD and turbidity. We confirm that the initial pH and PAC dosage have significant effects on COD and turbidity removal. The experimental data and model predictions agreed well and the removal efficiency of COD, turbidity, Fe, Pb and Cu reached respectively 61%, 96.4%, 97.1%, 99% and 100%.

Clinical assessment of mineral trioxide aggregate in the treatment of deep carious lesions.

OBJECTIVE: This clinical study aimed to assess the effectiveness of mineral trioxide aggregate (MTA) and calcium hydroxide (Ca[OH]2) in the treatment of deep carious lesions using the direct complete caries excavation technique. SUBJECTS AND METHODS: Hundred permanent molars/premolars were capped either with Ca (OH)2 (n = 49) or MTA (n = 51) and restored with composite resin in 73 patients. Periapical radiographs were taken prior to the treatment, at 6 months and 12 months. Two calibrated examiners clinically and radiographically assessed the periapical pathology and pulpal symptoms. Inter-group comparisons of the observed values were analyzed using Fisher's exact test. Significance was predetermined at α = 0.05. RESULTS: Recall rates were 100% at 6 and 12 months. Four teeth capped with Ca(OH)2 (two each at the end of 6 and 12 months) and one tooth capped with MTA (at the end of 12 months) received endodontic emergency treatment because of symptoms of irreversible pulpitis that were clinically and/or radiographically established. There was no significant difference between the protection of the tooth vitality and pulp capping agents at 6 and 12 months (P = 0.238, P = 0.606, respectively). CONCLUSION: Both materials were clinically applicable at the end of 12 months.