Tissue responses to an experimental calcium phosphate cement and mineral trioxide aggregate as materials for furcation perforation repair: a histological study in dogs

Does radiation therapy affect adhesion of tricalcium silicate cements to root dentin?

OBJECTIVE

This study aimed to analyze the effect of irradiation on the push-out bond strength of mineral trioxide aggregate (MTA) and Biodentine to radicular dentin.

METHODOLOGY

A total of 60 extracted mature human teeth with single root canals were categorized into two groups (irradiated and non-irradiated) (n=30). Each group was further divided into two sub-groups based on cements used (Biodentine and MTA). Then, a cumulative radiation dose of 60 Gy was divided into 30 fractions (two Gy for every fraction) and administered for five successive days per week over six weeks. Obturation was then performed using MTA and Biodentine. Afterwards, 1.5 mm thick horizontal sections were procured from the middle one-third of all the specimens and then subjected to push-out bond test. Results were analyzed using one-way analysis of variance with post-hoc Tukey's test.

RESULTS

The bond strength of Biodentine and MTA to irradiated teeth was lower than non-irradiated teeth. Highest push-out bond strength was observed in non-irradiated specimens filled with Biodentine (p=0), followed by irradiated specimens filled with Biodentine (p=0); non-irradiated specimens filled with MTA (p=0); and irradiated specimens filled with MTA (p=0.9).

CONCLUSION

The push-out bond strength of Biodentine and MTA to root canal dentin decreased significantly post irradiation.

Evaluating the Effect of Different Intra-Orifice Barriers and Various Bleaching Agents on the Fracture Resistance of Teeth After the Walking Bleach Procedure: An In Vitro Study

Objective This study aimed to evaluate the effect of three different commercially available intra-orifice barriers and bleaching agents on root canal-treated teeth. Materials and methods Forty-five freshly extracted single-rooted incisors, canine, and premolars were collected and stored in 10% formalin. Root canal procedures were performed on the extracted teeth and these were classified into three groups and three subgroups (n=5). Group 1: resin-modified glass ionomer cement (RMGIC); placed at the level of cemento-enamel junction (CEJ) and cured for 20 seconds. Group 2: Biodentin^TM (Septodont Ltd., Saint Maur des Fausse´s, France); powder and liquid were mixed according to the manufacturer's instructions and placed at the level of CEJ, and waited for 15 minutes to set. Group 3: bulk-fill composite; placed at the level of CEJ. Group A was treated with 35% carbamide peroxide (Ultradent Opalescence 35% PF regular). Group B was bleached with 35% hydrogen peroxide (Pola Office). Group C, which was the control group, was treated with distilled water. The bleaching procedure was repeated once every seven days for a period of three weeks. After bleaching, every sample was sectioned 2 mm above the level of CEJ to remove the crown. Auniversal testing machine (UTM) was used for the evaluation of the fracture resistance of teeth. Data were analyzed for significance by using analysis of variance (ANOVA) and further pair-wise comparison was performed by pos-hoc analysis. The level of significance was set at p<0.05 Results There was a significant difference between the fracture resistance of the three materials when bleached using distilled water (p<0.05). The fracture resistance of Group 3 was significantly greater than that of Group 2 and Group 1 (p<0.05). The difference in the fracture resistance between Group 1 and Group 2 was nonsignificant (p>0.05). Conclusion Walking bleach performed via bleaching agents 35% carbamide peroxide and 35% hydrogen peroxide leads to a reduction in the fracture resistance of endodontically treated teeth; 35% hydrogen peroxide causes more fracture resistance reduction than carbamide peroxide of the same concentration. The presence of intra-orifice barriers leads to greater fracture resistance and reinforcement of endodontically treated teeth that undergo the walking bleach procedure. Bulk-fill composite can be used as an intra-orifice barrier with good fracture resistance.

Effect of Intracoronal Sealing Biomaterials on the Histological Outcome of Endodontic Revitalisation in Immature Sheep Teeth-A Pilot Study

The influence of intracoronal sealing biomaterials on the newly formed regenerative tissue after endodontic revitalisation therapy remains unexplored. The objective of this study was to compare the gene expression profiles of two different tricalcium silicate-based biomaterials alongside the histological outcomes of endodontic revitalisation therapy in immature sheep teeth. The messenger RNA expression of TGF-β, BMP2, BGLAP, VEGFA, WNT5A, MMP1, TNF-α and SMAD6 was evaluated after 1 day with qRT-PCR. For evaluation of histological outcomes, revitalisation therapy was performed using Biodentine (n = 4) or ProRoot white mineral trioxide aggregate (WMTA) (n = 4) in immature sheep according to the European Society of Endodontology position statement. After 6 months' follow-up, one tooth in the Biodentine group was lost to avulsion. Histologically, extent of inflammation, presence or absence of tissue with cellularity and vascularity inside the pulp space, area of tissue with cellularity and vascularity, length of odontoblast lining attached to the dentinal wall, number and area of blood vessels and area of empty root canal space were measured by two independent investigators. All continuous data were subjected to statistical analysis using Wilcoxon matched-pairs signed rank test at a significance level of p < 0.05. Biodentine and ProRoot WMTA upregulated the genes responsible for odontoblast differentiation, mineralisation and angiogenesis. Biodentine induced the formation of a significantly larger area of neoformed tissue with cellularity, vascularity and increased length of odontoblast lining attached to the dentinal walls compared to ProRoot WMTA (p < 0.05), but future studies with larger sample size and adequate power as estimated by the results of this pilot study would confirm the effect of intracoronal sealing biomaterials on the histological outcome of endodontic revitalisation.

Biocompatibility, bioactive potential, porosity, and interface analysis calcium silicate repair cements in a dentin tube model

OBJECTIVES

This study is to evaluate biocompatibility, bioactive potential, porosity, and dentin/material interface of Bio-C Repair (BIOC-R), MTA Repair HP (MTAHP), and Intermediate Restorative Material (IRM).

MATERIALS AND METHODS

Dentin tubes were implanted into subcutaneous of rats for 7, 15, 30, and 60 days. Thickness of capsules, number of inflammatory cells (ICs), interleukin-6 (IL-6), osteocalcin (OCN), and von Kossa were evaluated. Porosity and material/dentin interface voids were also analyzed. Data were submitted to ANOVA and Tukey's tests (p < 0.05).

RESULTS

IRM capsules were thicker and contained greater ICs and IL-6-immunopositive cells at 7 and 15 days. BIOC-R capsules exhibited higher thickness and ICs at 7 days and greater IL-6 at 7 and 15 days than MTAHP (p < 0.05). At 30 and 60 days, no significant difference was observed among the groups. OCN-immunopositive cells, von Kossa-positive, and birefringent structures were observed in BIOC-R and MTAHP. MTAHP exhibited higher porosity and interface voids (p < 0.05).

CONCLUSIONS

BIOC-R, MTAHP, and IRM are biocompatible. Bioceramics materials demonstrate bioactive potential. MTAHP presented the highest porosity and presence of voids.

CLINICAL RELEVANCE

BIOC-R and MTAHP have adequate biological properties. BIOC-R demonstrated lower porosity and presence of voids, which may represent better sealing for its clinical applications.

Outcomes of furcal perforation management using Mineral Trioxide Aggregate and Biodentine: a systematic review

Furcal perforation is an iatrogenic or pathologic communication between the pulp chamber floor and the alveolar bone. The outcome of perforation sealing depends greatly on the tissue compatibility and bioactivity and sealing properties of the repair materials. Mineral trioxide aggregate (MTA) and Biodentine are currently the most used materials to treat this condition. The present systematic review aimed to report the treatment outcome of repaired furcal perforation using MTA and Biodentine and identify which material would yield a better outcome.

METHODOLOGY

A comprehensive search was conducted using the PubMed database to identify experimental studies and case reports that describe treatment of furcal perforation. Studies and case reports that evaluated the outcome of repaired furcal perforations using MTA and Biodentine, published in English from 2018 to April 2022, were identified. Unavailable full texts were excluded.

RESULTS

Initial screening of 724 articles (670 studies and 54 case reports). After discarding the duplicated studies, we reviewed 50 studies, selecting 13 for abstract analysis. We retrieved and evaluated full texts of eight studies and five case reports. Both materials had an equivalent success rate in the first three months but by 12 months Biodentine performed better than MTA clinically and radiographically.

CONCLUSIONS

Repair of furcal perforation with Biodentine yields a better outcome compared to MTA.

Valuation of angiogenesis in bovine xenografts implanted in intracorporal sites of rabbits as models of in-vivo bioreactors

ABSTRACT The aim of this study was to evaluate neovascularization of bovine xenografts implanted in intracorporeal sites of rabbits (bioreactors). 30 rabbits were used, divided into 6 groups, according to the evaluation time (7, 15, 30, 45, and 60 days); each animal received xenogenic implants in 3 different intracorporeal sites (A1 - omentum bag; A2 - intermuscular space of quadriceps femoris; A3 - subperiosteal of ilium bone). Histological assessments graded the presence of angiogenesis, the number of inflammatory cells, newly formed bone tissue, and the presence of giant cells. Histological analyses showed intense angiogenesis in all implanted xenografts. Presence of inflammatory infiltrate and giant cells at the A1 implant site and presence of bone neoformation at the A3 implant site were noted. Degeneration of implants and formation of a fibrous capsule were noted. When comparing the interaction of the site with the days of evaluation, statistical analysis showed a significant difference (p≤0.05) in any time of neovascularization analysis. The vascular endothelial growth factor (VEGF) and inflammatory cells of the omentum in its structure, may have contributed to the greater presence of neovessels and inflammatory cells, a fact that may indicate functionality as a possible bone substitute.

Comparison of Biocompatibility of Experimental Tricalcium Phosphate Cement versus Biodentin and Mineral Trioxide Aggregate used for Furcation Perforation Repair (in vivo study)

Background:

The interaction between the root canal system and the oral cavity caused by iatrogenic perforations significantly affects the treatment outcome and tooth survival.

Objectives:

This study was directed to compare the biocompatibility of an experimental tricalcium phosphate cement versus biodentine and mineral Trioxide aggregate used for furcation perforation repair in dogs.

Methods:

Perforations were done in 60 teeth (premolars and molars) of six adult dogs. Animals were divided randomly into 3 equal groups of 2 animals each according to the post-operative evaluation period of 1 week, 1 month, and 3-months. Each group was further subdivided into 4 subgroups according to either being repaired with the experimental tricalcium phosphate cement (n=6), or Biodentine (n=6), Mineral Trioxide Aggregate (MTA) (n=6), and positive control(n=2). After evaluation periods, tissue blocks were harvested and histologically examined.

Results:

No statistically significant difference was found regarding bone deposition scores and inflammatory reaction in the three groups after 1 week, 1 month, or 3 months. All three groups showed a statistically significant difference between all three time periods. Regardless of the repair material used, inflammation scores at 1-week showed the highest scores, decreasing over time except for the control group.

Conclusion:

The experimental material could be considered as a successful treatment option for repairing furcation perforation.

Does MTA provide a more favourable histological response than other materials in the repair of furcal perforations? A systematic review

BACKGROUND

There is no consensus on which furcal perforation repair material induces a more favourable histological response. This systematic review of laboratory studies provides an overview of the studies comparing repair materials in animal models.

OBJECTIVES

To evaluate whether mineral trioxide aggregate (MTA) yields a more favourable histological response than other materials when used to repair furcal perforations in animal experimental models.

METHODS

This review followed the PRISMA checklist. The studies included various materials used to repair furcal perforations and compared the histological responses with MTA. An electronic search was conducted in EMBASE, PubMed, Scopus and Web of Science up to 2 September 2020, with no language or publication date restrictions. Studies whose full text was unavailable were excluded. The ARRIVE and SYRCLE tools were used to assess the methodological quality and risk of bias (RoB) of the studies.

RESULTS

The studies included in the qualitative synthesis were conducted in rat (n = 3) and dog (n = 17) models. They were classified as having a low quality, high methodological heterogeneity and high RoB. MTA and Biodentine, the materials most often compared, reduced the inflammatory reaction to mild over time. In addition, a mineralized tissue was formed in all studies. The response yielded by MTA was better than or equivalent to that of the other tested materials.

DISCUSSION

This review confirmed that MTA is the reference standard material for furcal perforation repair. However, research using animal models has inherent limitations, and the substantial methodological heterogeneity across the studies included should be considered. Therefore, the knowledge generated by this systematic review should be translated into clinical practice cautiously.

CONCLUSIONS

Features described in the report and quality assessment guidelines, such as PRIASE, ARRIVE and SYRCLE, should guide researchers. Despite the high RoB and the low methodological quality of the studies included, findings indicated that MTA yields a more favourable histological response than other materials in the repair of furcal perforations.

REGISTRATION

PROSPERO (CRD42020181297).

Biocompatibility of NeoMTA Plus® versus MTA Angelus as delayed furcation perforation repair materials in a dog model

BACKGROUND

The biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials.

METHODS

Pulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value < 0.05 was considered significant.

RESULTS

In all subgroups, the control group exhibited the highest number of inflammatory cell count, followed by MTA Angelus group and the least inflammatory cell count was shown by NeoMTA Plus® group. There was a significant difference in the inflammatory cell count between the NeoMTA Plus® and MTA Angelus after one week (P < 0.05) while no significant differences were recorded between them after one month and three months (P > 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair.

CONCLUSION

NeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months.

The role of calcium ion release on biocompatibility and antimicrobial properties of hydraulic cements

Tricalcium silicate (TCS)-based materials produce calcium hydroxide as a byproduct of their hydration reaction. The present study investigated whether calcium ion release (CIR) affects their biological and antimicrobial properties when used as pulp protection materials. The effect of incorporation of micro-silica and calcium phosphate monobasic to radiopacified TCS-based materials was investigated. The commercial TCS-based Biodentine, Bio-C Pulpo, TotalFill Root Repair Material, TheraCal LC and a base/liner- ACTIVA BioACTIVE (Activa) were also evaluated. The hydration and CIR were monitored and correlated with biocompatibility and antimicrobial assessment of eluates. Overall, the additives altered the hydration and leaching profile of the prototype cements. The micro-silica inclusion resulted in a decreased long-term calcium hydroxide formation which was associated with neutralised cytotoxicity and antibacterial activity. Calcium phosphate did not alter the leaching profile, although a stronger antibacterial effect was induced. The commercial materials also had different CIR profiles. The water-based ones had higher CIR, and this was associated with stronger antimicrobial effect but not enhanced biological activity. Both TheraCal LC and Activa exhibited poor degree of conversion, low CIR, acceptable biocompatibility and moderate antibacterial activity. A positive correlation of CIR with antibacterial effectiveness was observed (0.3 < r < 0.49; p = 0.021, p = 0.011 for the two test bacterial cultures). No relation was shown between CIR and cytotoxicity (0.3 < r < 0.49; p = 0.150, p = 0.068 for the two cell cultures studied). The additives modified the CIR. The antimicrobial properties were dependent on the CIR; the cytotoxicity of the materials was unaffected.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Biodentine for Furcation Perforation Repair: An Animal Study with Histological, Radiographic and Micro-Computed Tomographic Assessment

Introduction:

Biodentine has been scarcely studied as a furcation perforation (FP) repair material, mostly by in vitro methodologies. This animal study aimed to compare the histological responses, radiographic, and micro-computed tomographic (micro-CT) outcomes after FP repair with Biodentine or ProRoot MTA (MTA) in dogs’ teeth.

Methods and Materials:

Fifty teeth from five dogs were divided into 4 groups: MTA (n=20, FP repaired with ProRoot MTA), BDT (n=20, FP repaired with Biodentine), PC (n=5, positive control, FP without repair) and NC (n=5, negative control, without perforation). The animals were euthanized after 4 months. Histological assessment included inflammatory cell infiltration, hard tissue resorption, hard tissue repair, and cement repair in the furcation area. Immediate postoperative and 4 months follow-up radiographs were compared for radiolucency in the furcation region. The volume of extruded material was quantified using micro-CT images.

Results:

The tested materials showed equivalent radiographic response, together with similar hard tissue resorption and repair but, BDT group showed significantly less inflammation, lower volume of extruded material and higher cement repair than MTA group.

Conclusion:

The outcomes of this study, taken together with other favorable results in literature, are highly suggestive that Biodentine is a promising biomaterial to be used for FP repair.

Calcium phosphate cements for bone engineering and their biological properties

Calcium phosphate cements (CPCs) are frequently used to repair bone defects. Since their discovery in the 1980s, extensive research has been conducted to improve their properties, and emerging evidence supports their increased application in bone tissue engineering. Much effort has been made to enhance the biological performance of CPCs, including their biocompatibility, osteoconductivity, osteoinductivity, biodegradability, bioactivity, and interactions with cells. This review article focuses on the major recent developments in CPCs, including 3D printing, injectability, stem cell delivery, growth factor and drug delivery, and pre-vascularization of CPC scaffolds via co-culture and tri-culture techniques to enhance angiogenesis and osteogenesis.

Animal models used in furcation perforation studies: A systematic review and comprehensive synthesis of model characteristics

In order to systematise furcation perforation (FP) experimental animal models described in the literature and to determine whether there is evidence that a model is superior to others, MEDLINE/PubMed, SciELO and Cochrane Library were searched to find studies which used animal models of FP. Data were gathered concerning model characteristics, chosen groups, sample numbers, type of outcomes, journal and main area studied. Twenty-five articles were included in this systematic review, four conducted in rodent models, three in non-human primates and 18 in dogs. Medians were six animals and 34 teeth per study; 10 teeth per test group and, when performed, six teeth per control group. Twenty-four studies investigated the use of materials for FP repair; eight also tested adjuvant materials/substances. Although there is no model which can be described as ideal and superior than others for FP studies, dogs appear to possess the most suitable model characteristics.

Silicon bioceramic loaded with vancomycin stimulates bone tissue regeneration

Porous ceramics doped with silicon and pure β-TCP were analyzed in terms of internal microstructure, cell behavior, and the percentage of newly formed bone. Additionally the materials were tested to determine which of the two had better properties to load and release vancomycin hydrochloride. Internal pore distribution and porosity were determined through high pressure mercury porosimetry and the specific surface area was measured by the Brunauer Emmet-Teller method. The proliferation and viability of the human osteoblast-like cell line MG-63 was studied to validate both materials. The materials were tested on eight New Zealand rabbits which created defects, 10 mm in diameter, in the calvaria bone. After 8 and 12 weeks a histological and histomorphometric analysis was performed. Si-β-TCP showed a higher porosity and specific surface area. The cytocompatibility test revealed acceptable results in terms of proliferation and viability whereas the percentage of new bone was higher in Si-β-TCP with a two-time study being statistically significant with 12 weeks of healing (p < 0.05).The vancomycin loaded within the ceramic scaffolds were burst released and the material had the ability to inhibit bacterial growth. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2307-2315, 2018.

In Vitro Sealing Properties of Calcium-Enriched Mixture and Mineral Trioxide Aggregate Orifice Barriers during Intra-Coronal Bleaching

Introduction:

This study aimed at evaluating the sealing properties of calcium-enriched mixture (CEM) compared to mineral trioxide aggregate (MTA) as a cervical barriers in intra-coronal bleaching.

Methods and Materials:

In this in vitro study, endodontic treatment was performed on 60 extracted human incisors and canines without canal calcification, caries, restorations, resorption or cracks. The teeth were then randomly divided into two experimental groups and two control groups (n=15). Then, CEM cement and MTA were applied as 3-mm intra-orifice barriers in the test groups; a mixture of sodium perborate and 30% hydrogen peroxide bleaching agents were placed within the pulp chamber for one week. Dye penetration method was used to evaluate the sealing ability of agents. Statistical analysis was performed using SPSS software. The Kendall coefficient was used to evaluate inter-observer agreement. The chi-squared test was used for statistical analysis.

Results:

The results showed that the penetration rates of CEM and MTA were the same as positive control group, with no significant differences (P=0.673 and P=0.408, respectively). However, there was a significant difference between the negative control group and CEM and MTA groups (P=0.001 for both groups). In addition, the sealing ability of MTA and CEM cement were not significantly different (P=0.682).

Conclusion:

During intra-coronal bleaching procedures CEM cement can be used as a cervical barrier with sealing properties comparable to that of MTA.

Push-Out Bond Strength and Surface Microhardness of Calcium Silicate-Based Biomaterials: An in vitro Study

OBJECTIVE

This was an in vitro evaluation of push-out bond strength and surface microhardness of calcium silicate-based biomaterials in coronal and apical root dentin.

MATERIALS AND METHODS

Ninety sections (2 mm thick) of coronal and apical root dentin were obtained from roots of 60 extracted teeth; the canals were enlarged to a standardized cavity diameter of 1.3 mm. Sections were randomly divided into 6 groups (n = 15 per group), and cavities were filled with Biodentine™, BioAggregate, or ProRoot mineral trioxide aggregate (MTA), according to the manufacturers' instructions. Push-out bond strength values were measured using a universal testing machine under a compressive load at a speed of 1 mm/min. Samples were analyzed under a light microscope to determine the nature of bond failure. Ten samples (2 mm thick) were prepared for all the materials, and Vickers microhardness was determined using a digital hardness tester. Data were analyzed using one-way analysis of variance and Tukey-Kramer multiple comparison tests at a significance level of p < 0.05.

RESULTS

Biodentine (42.02; 39.35 MPa) and ProRoot MTA (21.86; 34.13 MPa) showed significantly higher bond strengths than BioAggregate (6.63; 10.09 MPa) in coronal and apical root dentin, respectively (p < 0.05). Biodentine also differed significantly from ProRoot MTA in coronal dentin. Bond failure was predominantly adhesive in Biodentine and ProRoot MTA, while BioAggregate showed predominantly mixed failure. ProRoot MTA (158.52 HV) showed significantly higher microhardness and BioAggregate (68.79 HV) showed the lowest hardness.

CONCLUSION

Biodentine and ProRoot MTA showed higher bond strength and microhardness compared to BioAggregate.

Histologic tissue response to furcation perforation repair using mineral trioxide aggregate or dental pulp stem cells loaded onto treated dentin matrix or tricalcium phosphate

Objectives

The aim of this study is to compare the effect of treated dentine matrix (TDM) and tricalcium phosphate (TCP) scaffolds on odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs) in furcation perforations created in the pulp chamber floor of premolar teeth in dogs.

Material and methods

DPSCs were isolated and cultured from the dental pulp of the maxillary left second and third premolars of dogs. The DPSCs were loaded on TCP (SC+TCP) and TDM (SC+TDM) scaffolds and inserted into intentionally perforated pulp chamber floors of premolars in dogs; six teeth were used for each group. Three more groups of six specimens were created, and mineral trioxide aggregate (MTA), TDM, and TCP were inserted into the perforations to act as controls. An intact premolar and no treatment in the perforation site were used as positive and negative controls respectively. After 3 months, the animals were sacrificed and the type of inflammation, presence of dentine, continuation and type of cementum, type of connective tissue, and presence of foreign body reaction were evaluated, and significant differences were between groups determined using the Fisher’s exact test. The evaluation of the amount of inflammation and the percentage of new bone formation was evaluated using the Mann-Whitney U test.

Results

The negative control group was associated with severe inflammation and granulation tissue formation. In the positive control group, intact periodontal tissues and no inflammation were observed. Dentine bridge formation was not seen in specimens of any group. The specimens in the SC+TDM group were associated with significantly more bone formation than other groups (P < 0.001). The amount of inflammation was less than 10 % in specimens of all groups with the exception of three specimens in the TCP group that were categorized as 10–30 %. Chronic inflammation without foreign body reactions was the major pattern of inflammation in groups. Formation of cementum with a cellular and continuous appearance was seen in all specimens.

Conclusions

SC+TDM was associated with significantly more bone formation when used to repair uninfected furcation perforations in the premolar teeth of dogs.

Clinical relevance

Application of TDM as a biological scaffold in combination with DPSCs may offer an advantage during the repair of root perforation defects.

Effect of Calcium Hydroxide on the Push-out Bond Strength of Endodontic Biomaterials in Simulated Furcation Perforations

Introduction:

The aim of this in vitro study was to evaluate the effect of calcium hydroxide (CH) on push-out bond strength of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) cement in simulated furcation perforations.

Methods and Materials:

Furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. The teeth were then divided into 4 groups (n=20). In groups 1 and 3 CH was placed in the perforation for one week, before placement of WMTA and CEM. In groups 2 and 4 perforations were repaired without placement of CH. In groups 1 and 2 the perforation sites were repaired with WMTA and CEM cement was used in groups 3 and 4. After 7 days, the push-out test was carried out using a universal testing machine. Data were analyzed with two-way ANOVA. The level of significance was set at 0.05.

Results:

The maximum and minimum bond strength values were recorded in the WMTA/CH (13.08±1.8 MPa) and CEM cement groups (8.03±0.98 MPa), respectively. There were significant differences in resistance to dislodgement between the WMTA/CH and other groups (P<0.05).

Conclusion:

Placement of CH before placement of WMTA in furcation perforation improves the push-out bond strength of this material.

Repair of bone defect by nano-modified white mineral trioxide aggregates in rabbit: A histopathological study

Background

Many researchers have tried to enhance materials functions in different aspects of science using nano-modification method, and in many cases the results have been encouraging. To evaluate the histopathological responses of the micro-/nano-size cement-type biomaterials derived from calcium silicate-based composition with addition of nano tricalcium aluminate (3CaO.Al2O3) on bone healing response.

Material and Methods

Ninety mature male rabbits were anesthetized and a bone defect was created in the right mandible. The rabbits were divided into three groups, which were in turn subdivided into five subgroups with six animals each based on the defect filled by: white mineral trioxide aggregate (WMTA), Nano-WMTA, WMTA without 3CaO.Al2O3, Nano-WMTA with 2% Nano-3CaO.Al2O3, and empty as control. Twenty, forty and sixty days postoperatively the animals were sacrificed and the right mandibles were removed for histopathological evaluations. Kruskal-Wallis test with post-hoc comparisons based on the LSMeans procedure was used for data analysis.

Results

All the experimental materials provoked a moderate to severe inflammatory reaction, which significantly differed from the control group (p< 0.05). Statistical analysis of bone formation and bone regeneration data showed significant differences between groups at 40- and 60- day intervals in all groups. Absence of 3CaO.Al2O3 leads to more inflammation and foreign body reaction than other groups in all time intervals.

Conclusions

Both powder nano-modification and addition of 2% Nano-3CaO.Al2O3 to calcium silicate-based cement enhanced the favorable tissue response and osteogenesis properties of WMTA based materials.

Key words:Bone regeneration, cement, endodontics, histopathology, nano-wmta, tricalcium aluminate.

Physical properties and biological/odontogenic effects of an experimentally developed fast-setting α-tricalcium phosphate-based pulp capping material

Background

Recently, fast-setting α-tricalcium-phosphate (TCP) cement was developed for use in the pulp capping process. The aim of this study was to investigate the physical properties and biological effects of α-TCP cement in comparison with mineral trioxide aggregate (MTA).

Methods

We measured the setting time, pH values, compressive strength, and solubility of the two materials. We evaluated biocompatibility on the basis of cell morphology and a viability test using human dental pulp cells (hDPCs). Chemical composition of each material was analyzed by energy dispersive x-ray spectroscopic (EDS) analysis. The expression of odontogenic-related genes was evaluated by Western blotting and immunofluorescence. The calcified nodule formation was measured by Alizarin red staining. We performed the pulp capping procedure on rat teeth for histological investigation. The data were analyzed by an independent t-test for physical properties, one-way ANOVA for biological effects, and the Mann-Whitney U test for tertiary dentin formation. A P value of less than 0.05 was considered statistically significant for all tests.

Results

The setting time, pH values, and compressive strength of α-TCP was lower than that of MTA (P < 0.05); however, the solubility of α-TCP was higher than that of MTA (P < 0.05). The resultant cell viability observed with the two materials was similar (P > 0.05). Scanning electron microscopy (SEM) revealed that cells attached to both materials were flat and had cytoplasmic extensions. The expression of odontogenic-related markers and mineralized nodule formation were higher in the two experimental groups compared to the control group (P < 0.05). Continuous tertiary dentin was formed underneath the capping materials in all samples of the tested groups.

Conclusions

Our study demonstrated that the α-TCP exhibited biocompatibility and odontogenicity comparable to MTA, whereas it had a quicker setting time.

Surgical management of a failed internal root resorption treatment: a histological and clinical report

This article presents the successful surgical management of a failed mineral trioxide aggregate (MTA) orthograde obturation of a tooth with a history of impact trauma and perforated internal root resorption. A symptomatic maxillary lateral incisor with a history of perforation due to internal root resorption and nonsurgical repair using MTA was referred. Unintentional overfill of the defect with MTA had occurred 4 yr before the initial visit. The excess MTA had since disappeared, and a radiolucent lesion adjacent to the perforation site was evident radiographically. Surgical endodontic retreatment was performed using calcium enriched mixture (CEM) cement as a repair material. Histological examination of the lesion revealed granulation tissue with chronic inflammation, and small fragments of MTA encapsulated within fibroconnective tissue. At the one and two year follow up exams, all signs and symptoms of disease had resolved and the tooth was functional. Complete radiographic healing of the lesion was observed two years after the initial visit. This case report illustrates how the selection of an appropriate approach to treatment of a perforation can affect the long term prognosis of a tooth. In addition, extrusion of MTA into a periradicular lesion should be avoided.

Self-setting calcium orthophosphate formulations

In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are bioactive and biodegradable grafting bioceramics in the form of a powder and a liquid. After mixing, both phases form pastes, which set and harden forming either a non-stoichiometric calcium deficient hydroxyapatite or brushite. Since both of them are remarkably biocompartible, bioresorbable and osteoconductive, self-setting calcium orthophosphate formulations appear to be promising bioceramics for bone grafting. Furthermore, such formulations possess excellent molding capabilities, easy manipulation and nearly perfect adaptation to the complex shapes of bone defects, followed by gradual bioresorption and new bone formation. In addition, reinforced formulations have been introduced, which might be described as calcium orthophosphate concretes. The discovery of self-setting properties opened up a new era in the medical application of calcium orthophosphates and many commercial trademarks have been introduced as a result. Currently such formulations are widely used as synthetic bone grafts, with several advantages, such as pourability and injectability. Moreover, their low-temperature setting reactions and intrinsic porosity allow loading by drugs, biomolecules and even cells for tissue engineering purposes. In this review, an insight into the self-setting calcium orthophosphate formulations, as excellent bioceramics suitable for both dental and bone grafting applications, has been provided.

Calcium orthophosphates in dentistry

Dental caries, also known as tooth decay or a cavity, remains a major public health problem in the most communities even though the prevalence of disease has decreased since the introduction of fluorides for dental care. Therefore, biomaterials to fill dental defects appear to be necessary to fulfill customers' needs regarding the properties and the processing of the products. Bioceramics and glass-ceramics are widely used for these purposes, as dental inlays, onlays, veneers, crowns or bridges. Calcium orthophosphates belong to bioceramics but they have some specific advantages over other types of bioceramics due to a chemical similarity to the inorganic part of both human and mammalian bones and teeth. Therefore, calcium orthophosphates (both alone and as components of various formulations) are used in dentistry as both dental fillers and implantable scaffolds. This review provides brief information on calcium orthophosphates and describes in details current state-of-the-art on their applications in dentistry and dentistry-related fields. Among the recognized dental specialties, calcium orthophosphates are most frequently used in periodontics; however, the majority of the publications on calcium orthophosphates in dentistry are devoted to unspecified "dental" fields.

Sealing ability of mineral trioxide aggregate, calcium phosphate cement, and glass ionomer cement in the repair of furcation perforations

OBJECTIVES

The purpose of this study was to evaluate the in vitro sealing ability of three repair materials. Mineral trioxide aggregate (MTA; Group A), calcium phosphate cement (CPC; Group B), and light cured glass ionomer cement (GIC; Group C) when used to repair the perforation created in the pulpal floor of fifty extracted human permanent molars.

MATERIALS AND METHODS

Preparation of access openings and furcation perforations were done, and the teeth divided into five experimental groups (A, B, C) including two controls (D, E) with ten samples in each group randomly. Following the repair procedure, the pulp chambers and access openings were filled with composite resin and immersed in 2% methylene blue solution for 48 hours. The teeth were sectioned longitudinally and the linear dye penetration measured under a stereomicroscope.

RESULTS

The comparison of the linear length of micro-leakage (mm) among the experimental groups revealed no significant difference (p = 0.332). On calculating the percentage of depth of leakage to the total length of the perforation, it was observed that the mean leakage was 35.5% in Group A, 53.6% in Group B and the highest, 87.5% in Group C. The mean of leakage percentage was statistically significant by Kruskal-Wallis test (p = 0.003). The results indicated that the dye penetration used as furcation perforation repair material was least with mineral trioxide aggregate. Comparing the depth of penetration of dye, 50% of the Group A samples showed less than 25% of depth penetration. While 40% of Group B cases had more than 50% dye penetration. In our study, all Group C teeth had > or = 50% dye penetration.

CONCLUSIONS

The present study indicated that GIC had the greatest dye penetration followed by CPC and MTA. Mineral trioxide aggregate and calcium phosphate cement had comparatively better sealing ability than glass ionomer cement.

Osseous reaction to implantation of two endodontic cements: Mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)

Aim: The aim of the present in vivo study was to determine bone tissue reaction to calcium enriched mixture (CEM) and mineral trioxide aggregate (MTA) using a rat femur model. Study Design: Sixty-three rats were selected and randomly divided into three groups of 21 each [experimental groups (n=15), control (n=6)]. Implantation cavities were prepared in each femoral bone and randomly filled with the biomaterials only in the experimental groups. The animals in three groups were sacrificed 1, 4, and 8 weeks postoperatively. Histologic evaluations comprising inflammation severity and new bone formation were blindly made on H&E-stained decalcified 6-µm sections. Results: At 1, 4, and 8 weeks after implantation number of inflammatory cells had decreased in the CEM, MTA and control groups, respectively, with no statistically significant differences. Conversely, new bone formation had increased in all the experimental and control groups, without statistically significant differences. Conclusion: The results suggest that biocompatibility of MTA, as gold standard, and CEM cement as a new endodontic biomaterial are comparable

Key words:Endodontics, MTA,CEM, osseous reaction.

Periradicular Tissue Responses to Biologically Active Molecules or MTA When Applied in Furcal Perforation of Dogs' Teeth

The aim of this study was the comparative evaluation of inflammatory reactions and tissue responses to four growth factors, or mineral trioxide aggregate (MTA), or a zinc-oxide-eugenol-based cement (IRM) as controls, when used for the repair of furcal perforations in dogs' teeth. Results showed significantly higher inflammatory cell response in the transforming growth factorβ1 (TGFβ1) and zinc-oxide-eugenol-based cement (IRM) groups and higher rates of epithelial proliferation in the TGFβ1, basic fibroblast growth factor (bFGF), and insulin growth factor-I (IGF-I) groups compared to the MTA. Significantly higher rates of bone formation were found in the control groups compared to the osteogenic protein-1 (OP-1). Significantly higher rates of cementum formation were observed in the IGF-I and bFGF groups compared to the IRM. None of the biologically active molecules can be suggested for repairing furcal perforations, despite the fact that growth factors exerted a clear stimulatory effect on cementum formation and inhibited collagen capsule formation. MTA exhibited better results than the growth factors.

Radiographic evaluation of furcal perforations sealed with different materials in dogs' teeth

OBJECTIVE

The objective of this work was to evaluate, using radiographic images, the behavior of four materials used to repair root perforations in dogs' teeth.

MATERIAL AND METHODS

Second and third premolars of 6 dogs were used. The 48 teeth were randomly divided into 4 groups (n=12) and the perforations were sealed with one of the following materials: MTA, AH Plus, Vitremer and gutta-percha. Dogs were submitted to general anesthesia, teeth were radiographed and pulp was accessed. Perforations were done, at the maximum curve of the pulp floor, sealed and the accessed coronal cavity was filled with glass ionomer cement (Vidrion R). After 90 days, the dogs were sacrificed and the last x-ray image was taken. Images were analyzed for the presence/absence of periodontal lesions at the perforation region. Data were analyzed statistically by chi-square test at 5% significance level.

RESULTS

There were no statistically significant differences (p>0.05) among AH Plus, Vitremer and gutta-percha groups. MTA produced the smallest number of periodontal lesions (p<0.05).

CONCLUSIONS

It may be concluded that none of the tested materials was able to preserve the integrity of the periodontal tissues in the furcation region, and the use of MTA resulted in the least formation of adjacent periodontal bone lesions revealed by the radiographic comparisons.

Evidenced-based review of clinical studies on periodontics

Periodontal diseases have several implications for the practice of endodontics. First, advanced periodontitis often has direct implications for the long-term prognosis of the case and requires careful evaluation and coordinated treatment of both the periodontic and endodontic diseases. Second, the potential for functional interactions between odontogenic pathoses and marginal periodontitis requires careful collection of clinical observations and monitoring the outcome of various treatments. In this section, we provide an analysis of recent clinical studies in this area.

Calcium Orthophosphate Cements and Concretes

In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA) or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone), calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report

Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11–20 months (mean, 13.9 ± 3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8 ± 1.7 mm and mean clinical attachment level gain 4.3 ± 2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8 ± 1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8 ± 2.8% and 32.1 ± 8.3%, respectively. Within their limits, the present findings indicate that the described surgical approach may be successfully used in certain clinical cases to simultaneously treat intrabony defects and to reconstruct the resorbed alveolar ridge.

Efficacy of open flap debridement with and without enamel matrix derivatives in the treatment of mandibular degree II furcation involvement

The aim of the present study was the evaluation of the efficacy of open flap debridement (OFD) with and without enamel matrix derivatives (EMD) in the management of class II furcation involvement. Twenty similar bilateral class II furcation defects in ten healthy nonsmoker patients were selected. One defect in each subject was treated with OFD alone (OFD group) and the contralateral one with OFD and simultaneous application of enamel matrix derivatives (EMD group). Clinical probing depth, vertical clinical attachment level, horizontal clinical attachment level, and the location of the gingival margin, horizontal probing depth of bony defect (E-HPD), vertical depth of bone crest, vertical depth of the base of bony defect (V-DBD), and length of the intrabony defect were measured at baseline and during reentry surgery after 6 months. Wilcoxon signed-rank test and Mann-Whitney U test were used to analyze the data. Among soft tissue parameters, only horizontal attachment gain in EMD was significantly more than OFD (P = 0.002). Application of EMD significantly enhanced the horizontal (E-HPD) and vertical (V-DBD) resolution of the bony defect (P < 0.05). In conclusion, it seems that the adjunctive use of EMD enhances the efficiency of OFD in the management of mandibular class II furcation defects.