Periapical Tissue Responses and Cementum Regeneration with Amalgam, SuperEBA, and MTA as Root-End Filling Materials

Biocompatibility of root-end filling materials: recent update

The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials.

Apexificação com hidróxido de cálcio ou agregado trióxido mineral: revisão sistemática

OBJETIVO: O propósito deste trabalho foi realizar uma revisão sistemática de estudos clínicos, que avaliaram a eficácia de hidróxido de cálcio [Ca(OH)2] e agregado trióxido mineral (MTA) na terapia de dentes despolpados com rizogênese incompleta. METODOLOGIA: Foram utilizadas as seguintes bases de dados: PUBMED, WEB OF SCIENCE, SCOPUS com a palavra-chave "apexification" e BIREME com as palavras-chave "apexification", "apexificação" e "apicificação", no período de junho de 1992 a julho de 2012, com publicações em inglês e português. A revisão considerou como critério de inclusão estudos clínicos que avaliavam comparativamente o uso de Ca(OH)2 e MTA na terapia de dentes permanentes humanos com rizogênese incompleta. RESULTADO: Por palavras-chave pesquisadas, foi encontrado um total de 2.322 estudos. Contudo, apenas três estudos satisfizeram os critérios de inclusão, ou seja, estudos clínicos controlados que avaliaram comparativamente o uso de Ca(OH)2 e MTA na terapia de apexificação em dentes permanentes aplicados em seres humanos. CONCLUSÃO: Os resultados demonstraram que igualmente MTA ou hidróxido de cálcio são indicados para a técnica de apexificação em dentes permanentes imaturos. Não obstante, o número reduzido de ensaios clínicos controlados é um obstáculo na busca da evidência científica e sinaliza para a necessidade de novos estudos clínicos longitudinais com ambos os materiais.

Root-end filling with cement-based materials: An in vitro analysis of bacterial and dye microleakage

Background:

One ideal property of a root-end filling material is its apical sealing ability. The aim of this in vitro study was to assess bacterial and dye microleakage of white and gray mineral trioxide aggregate (WMTA and GMTA), Portland cement and calcium-enriched mixture (CEM) cement used as root-end filling material, and to assess the agreement between these two test methods.

Materials and Methods:

Fifty-four single-rooted teeth were used. The roots were randomly divided into four study and two control groups. After decoronation, root canals were instrumented and filled with gutta-percha and AH26 sealer. Root-ends were resected 3 mm above the root-end and 3 mm deep cavities were prepared. Root-end cavities were filled with each material. Enterococcus faecalis and methylene blue dye were used for determination of bacterial and dye leakage respectively. Data were analyzed using Fisher's Exact Test, one-way ANOVA, Kaplan-Meier analysis, and Cohen's Kappa.

Results:

There was 100% bacterial leakage in Portland cement and CEM cement, 58.3% in GMTA, and 91.7% in WMTA. GMTA showed significantly less bacterial leakage than Portland cement and CEM cement (P < 0.05). In those samples with leakage occurrence, times of observation of leakage were not significantly different; however, by survival analysis, the results of the GMTA group were significantly different from those of the CEM cement and Portland groups. The difference in complete dye leakage was not significant. There was poor agreement between dye and bacterial leakage methods.

Conclusion:

CEM cement provides leakage results comparable to other commonly used root-end filling materials such as WMTA.

Influence of a bioceramic root end material and mineral trioxide aggregates on fibroblasts and osteoblasts

OBJECTIVE

The biocompatibility of materials used in endodontic treatment is of high importance, because they can come in contact with periradicular tissues and there is a risk of possible systemic toxicity. The aim of the present study was to investigate the in vitro reaction to a bioceramic based root end material in comparison to mineral trioxide aggregates (MTA) as the established gold standard.

DESIGN

The root end materials grey MTA Angelus (GMTA), white MTA Angelus (WMTA), ProRoot MTA, and EndoSequence Root Repair Material (ERRM) were incubated with human periodontal ligament fibroblasts and osteoblasts (10(4)cells/ml) for up to 96h. Cell proliferation (RFU) was determined by means of the Alamar Blue assay. In addition, fluorescence staining was carried out to visually monitor cell growth and morphology.

RESULTS

For most of the observational time period of up to 96h, there was no statistically significant difference between the proliferation rates of the control cells and those in contact with ERRM. In contrast, the mineral trioxide based materials caused from 24 to 96h significantly lower proliferation rates in comparison to the controls (p<0.001). For proliferation rates of cells in contact with MTAs and ERRM significant differences were observed throughout the whole observation time for the osteoblasts, but only up to 24h for the human periodontal ligament fibroblasts.

CONCLUSION

Within the limits of this study the results suggest that the bioceramic root end material is biocompatible, but needs to be investigated in clinical studies before it can be recommended as retrograde sealer in endodontic practice.

Nanohydroxyapatite increases BMP-2 expression via a p38 MAP kinase dependent pathway in periodontal ligament cells

OBJECTIVE

Bone morphogenetic protein (BMP)-2 promotes the osteoblastic differentiation of human periodontal ligament (PDL) cells, which play a pivotal role in periodontal regeneration. Recently, nano-sized hydroxyapatite (nano-HA) has been highlighted due to its advantageous features over micro-sized materials.

DESIGN AND RESULTS

We investigated the effect of nano-HA on BMP-2 expression in human PDL cells. Real time PCR analysis revealed that the expression of BMP-2 increased upon stimulation with nano-HA in dose- and time-dependent manners. An immunofluorescence assay demonstrated the synthesis of BMP-2 proteins. Concentrations of Ca(2+) as well as phosphate (Pi) in culture supernatants were unchanged, suggesting that nano-HA functioned as a nanoparticle rather than as a possible source for releasing Ca(2+) and/or Pi extracellularly, which were shown to also enhance the expression of BMP-2. Nano-HA-induced BMP-2 expression was dependent on the p38 MAP kinase pathway because increases in BMP-2 expression were inhibited by treatment with SB203580, a p38 inhibitor, and phosphorylation of p38 was detected by Western blotting.

CONCLUSIONS

This novel mechanism of nano-HA will be important for the rational design of future periodontal regeneration.

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.

Biocompatibility and osteogenic potential of new generation endodontic materials established by using primary osteoblasts

INTRODUCTION

Generex A and Generex B (calcium silicate based), Capasio (calcium-phospho-alumino silicate based) along with Ceramicrete-D (magnesium phosphate based) are being introduced as a new generation of endodontic materials with the potential to facilitate bone healing. The aim of this study was to evaluate the biocompatibility and osteogenic potential of these new materials by using primary osteoblasts.

METHODS

Primary osteoblasts were prepared from rat calvaria and exposed to mineral trioxide aggregate (MTA), Generex A, Generex B, Capasio, and Ceramicrete-D prepared to standardized size and shape (n = 5). Trypan blue staining was used to evaluate cell viability from 1-6 days. Mineralization potential was evaluated by scanning electron microscopy for the presence of mineralized nodules. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

Only Generex A and MTA allowed cell growth and proliferation throughout the experiment. There were statistically significant differences between groups throughout the experiment beginning on day 1. The greatest amount of cell growth was consistently observed with Generex A and MTA. There was no difference in mineralized nodule formation between any test materials.

CONCLUSIONS

Generex A was the only new generation endodontic material that supported primary osteoblast growth; no material besides MTA facilitated nodule formation.

Clinical technique for invasive cervical root resorption

This clinical case report describes the diagnosis and treatment of an external invasive cervical resorption. A 17-year-old female patient had a confirmed diagnosis of invasive cervical resorption class 4 by cone beam computerized tomography. Although, there was no communication with the root canal, the invasive resorption process was extending into the cervical and middle third of the root. The treatment of the cervical resorption of the lateral incisor interrupted the resorptive process and restored the damaged root surface and the dental functions without any esthetic sequelae. Both the radiographic examination and computed tomography are imperative to reveal the extent of the defect in the differential diagnosis.

Treatment of open apex teeth using two types of white mineral trioxide aggregate after initial dressing with calcium hydroxide in children

BACKGROUND

The clinical and radiographic success of two types of white mineral trioxide aggregate (MTA) as apical barriers in non-vital immature permanent incisors in children was investigated.

MATERIALS AND METHODS

Following an initial dressing with calcium hydroxide, MTA apical barriers were placed in 22 non-vital traumatized, permanent incisors with open apices in 21 children (mean age 10years). Teeth were alternately assigned to either white MTA ProRoot(®) or white MTA Angelus groups and treated by two operators. Clinical and radiographic reviews took place at baseline, 3 months and every 6months thereafter. Two other calibrated, blinded examiners evaluated all radiographs. Examiner agreement was assessed using Kappa-Cohen tests. Results were analysed using Fisher's exact tests and repeated measures anova.

RESULTS

The mean follow-up time was 23.4months. There were no statistically significant differences in clinical or radiographic outcomes between the two groups. The overall clinical success and relative radiographic success rate was 95.5%. Statistically significant reduction in periapical pathosis was shown over time in both groups (P<0.05). A significant relationship was identified between non-divergent apical anatomy and ideal positioning of the MTA plug in all teeth (P=0.04). Interestingly, coronal discolouration was observed in 22.7% of teeth following white MTA placement.

CONCLUSIONS

Apical barrier placement using both white MTA ProRoot(®) and white MTA Angelus after an initial calcium hydroxide dressing showed similar favourable clinical and radiographic outcomes.

Sealing ability of MTA and amalgam in different root-end preparations and resection bevel angles: an in vitro evaluation using marginal dye leakage

This in vitro study evaluated the effect of different apicoectomy angles, instruments used in root-end preparation, and dental materials used in retrofilling on apical sealing. Root ends were resected at 45 or 90 degrees in 80 single-rooted teeth. For each type of apicoectomy, root-end cavities were prepared with either a round carbide #2 bur or an S12/90D ultrasonic tip. The root-end cavities in each subgroup (apicoectomy + root-end preparation) were filled with silver amalgam without zinc (Am) or with gray mineral trioxide aggregate -Angelus (MTA), and the specimens were immediately immersed in 0.2% rhodamine B for 24 h. Sealing was evaluated based on the dyed cross-sectional dentin area. Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. No group showed complete sealing of root-end areas. The only significant factor affecting microleakage was dental material, with MTA exhibiting less leakage.

Reaction of rat connective tissue to Mineral Trioxide Aggregate and Diaket

BACKGROUND

The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.

METHODS

Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.

RESULTS

There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.

CONCLUSIONS

It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.

Endodontic essay

"It has been said that Mineral Trioxide Aggregate is driving an endodontic revolution. Discuss this statement considering the biological and clinical attributes of this innovative material."

Apical surgery: A review of current techniques and outcome

Apical surgery is considered a standard oral surgical procedure. It is often a last resort to surgically maintain a tooth with a periapical lesion that cannot be managed with conventional endodontic (re-)treatment. The main goal of apical surgery is to prevent bacterial leakage from the root-canal system into the periradicular tissues by placing a tight root-end filling following root-end resection. Clinicians are advised to utilize a surgical microscope to perform apical surgery to benefit from magnification and illumination. In addition, the application of microsurgical techniques in apical surgery, i.e., gentle incision and flap elevation, production of a small osteotomy, and the use of sonic- or ultrasonic driven microtips, will result in less trauma to the patient and faster postsurgical healing. A major step in apical surgery is to identify possible leakage areas at the cut root face and subsequently to ensure adequate root-end filling. Only a tight and persistent apical obturation will allow periapical healing with good long-term prognosis. The present paper describes current indications, techniques and outcome of apical surgery.

Periapical bone regeneration after endodontic microsurgery with three different root-end filling materials: amalgam, SuperEBA, and mineral trioxide aggregate

INTRODUCTION

The purpose of this study was to determine the bone regeneration potential to different root-end filling materials by evaluating the distance between the materials and newly regenerated bone after root-end surgery.

MATERIAL AND METHODS

Periapical lesions were induced in premolars and molars of five female beagle dogs. The teeth were treated endodontically after the development of the lesions. After 1 week, the teeth underwent root-end surgery using modern microsurgical techniques. Three different root-end filing materials were used: amalgam (Tytin; Kerr Mfg Co, Romulus, MI), SuperEBA (Bosworth, Skokie, IL), and mineral trioxide aggregates (MTA; Dentsply, York, PA). After 4 months, the dogs were sacrificed, and the jaws were prepared for histological sectioning. The distances from the root-end filling materials to the regenerated bone were determined by the evaluation of microradiographic images of the sections with imaging software (Sigma Scan/Image; Jandel Scientific Software, San Rafael, CA). The results were statistically analyzed with analysis of variance using Sigma Stat software (Jandel Scientific Software, San Rafael, CA).

RESULTS

The mean distances from the newly regenerated bone were 0.397 +/- 0.278 mm in the MTA group, 0.756 +/- 0.581 mm in the SuperEBA group, and 1.290 +/- 0.386 mm in the amalgam group. There was a statistically significant difference between the amalgam and MTA groups (p < 0.05). No significant differences existed for amalgam versus SuperEBA and SuperEBA versus MTA.

CONCLUSION

MTA showed the most favorable periapical tissue response. The distance from MTA to the regenerated bone was similar to the normal average periodontal ligament thickness in dogs.

Microscopic appearance and apical seal of root canals filled with gutta-percha and ProRoot Endo Sealer after immersion in a phosphate-containing fluid

AIM

To investigate the sealing quality of ProRoot Endo Sealer, a calcium silicate-based sealer and its morphologic characteristics after immersion in a phosphate-containing fluid (PCF).

METHODOLOGY

Single-rooted canals were filled with gutta-percha and either ProRoot Endo Sealer or two commercially available zinc oxide eugenol (ZOE)-based and epoxy resin-based sealers. The sealers were allowed to set for 6 days and the filled teeth were immersed in PCF for 24 h before fluid leakage evaluation. After initial leakage evaluation at the 7th day, each filled root was restored and reimmersed in PCF for 28 days before the second phase of leakage evaluation at 35 days. Cryofractured specimens of additional teeth filled with the three sealers were examined using scanning electron microscopy after immersion in PCF for the two periods.

RESULTS

One-way repeated measures anova and Tukey test revealed significant differences between the ZOE-based sealer at 35 days and the calcium silicate-based sealer at 35 days (P < 0.001), and between the ZOE-based sealer at 7 days and the calcium silicate-based sealer at 35 days (P = 0.001). No difference was found between the epoxy resin-based sealer and the calcium silicate-based sealer after both storage periods. Cryofractured calcium silicate-based sealer specimens demonstrated apatite-like crystalline deposits along the apical and middle thirds of the canal walls via transformation from amorphous calcium phosphate-like precursors.

CONCLUSIONS

ProRoot Endo Sealer is comparable in sealing quality to the epoxy resin-based sealer and seals better than the ZOE-based sealer after immersion in PCF. The calcium silicate-based sealer also demonstrates ex vivo bioactivity when it comes into contact with phosphate ions.

Mineral trioxide aggregate in paediatric dentistry

OBJECTIVE

The aim of this study was to present a review of the reported literature on: (i) the physical and chemical properties; and (ii) clinical applications of mineral trioxide aggregate (MTA) in the practice of paediatric dentistry.

METHOD

Electronic literature search of scientific papers from January 1993 to June 2008 was carried out on the MEDLINE, Embase, Entrez Pubmed, and Scopus databases using specific key words. The search yielded 448 papers, out of which 100 were identified as conforming to the applied criteria. These papers formed the basis of the review and the clinical scenarios presented which demonstrate the application of MTA in the practice of paediatric dentistry.

CONCLUSION

Paediatric dentists have successfully employed MTA in a variety of endodontic/restorative applications since the late 1990s. Clinical impressions have generally been favourable and support the findings of laboratory and animal-based investigations. Very few clinical studies have been reported so far in humans, and although these have been positive, the body of research is currently insufficient to enable a meaningful systematic review and meta-analysis.

A prospective clinical study of periradicular surgery using mineral trioxide aggregate as a root-end filling

A prospective outcome study of periradicular surgery using microsurgical techniques and root-end filling with mineral trioxide aggregate (MTA) was performed. Nonhealing endodontically treated teeth (n = 321) were included in the study. Surgery was completed under local anesthesia using a standardized clinical protocol. Patients were recalled periodically and examined for signs and symptoms of failure. Thirty-nine teeth were lost from recall. Of the 276 teeth examined, 163 showed complete healing radiographically with no other signs and symptoms; 82 teeth had no symptoms but incomplete or uncertain healing, and 31 teeth showed nonhealing (three had persistent pain despite evidence of complete radiologic healing and eight teeth did not heal for reasons unrelated to the surgical treatment). The overall success rate was 88.8%, including all teeth with no clinical symptoms. In this study, the use of MTA as a root-end filling, following microsurgical techniques, showed a high success rate.

Contemporary management of lateral root perforation diagnosed with the aid of dental computed tomography

Lateral root perforation unnoticed during post-space preparation, and followed by post cementation, can subsequently be challenging to diagnose in the labio-lingual plane due to the two-dimensional nature of conventional radiography. This paper demonstrates the application of a recently developed three-dimensional imaging system, cone beam computed tomography, in the diagnosis of iatrogenic root perforation. A clinical case is reported where labial post perforation in a maxillary central incisor occurring 15 years previously presented with a sinus tract and radiolucent lesion. Non-surgical retreatment and perforation repair using mineral trioxide aggregate was performed with the aid of an operating microscope. The sinus tract resolved with radiographic evidence of healing at 1-year recall.

Prospective clinical study evaluating endodontic microsurgery outcomes for cases with lesions of endodontic origin compared with cases with lesions of combined periodontal-endodontic origin

The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the healing success of cases having a lesion of endodontic origin compared with cases having a lesion of combined endodontic-periodontal origin. Data were collected from patients in the Department of Conservative Dentistry, Dental College, Yonsei University, Seoul, Korea between March 2001 and June 2005. A total number of 263 teeth from 227 patients requiring periradicular surgery were included in this study. Patients were recalled every 6 months for 2 years and every year thereafter to assess clinical and radiographic signs of healing. A recall rate of 73% (192 of 263 patients) was obtained. The successful outcome for isolated endodontic lesions was 95.2%. In endodontic-periodontal combined lesions, successful outcome was 77.5%, suggesting that lesion type (ABC vs DEF) had a strong effect on tissue and bone healing.

Eugenol Modulates Cyclooxygenase-2 Expression Through the Activation of Nuclear Factor Kappa B in Human Osteoblasts

Because eugenol is a major component of root canal sealers and retrograde filling materials, its effects on periapical bone healing are therefore of concern. In this study, the effects of eugenol on the activation of nuclear factor kappa B (NF-kappaB) and the expression of cyclooxygenase-2 (COX-2) in human osteoblasts were investigated. The results showed that eugenol activated the nuclear translocation of NF-kappaB. In addition, COX-2 protein expression in osteoblasts was induced by eugenol in a dose-dependent manner. Furthermore, the eugenol-modulated COX-2 expression was inhibited by an NF-kappaB inhibitor, N-acetylcysteine. Taken together, eugenol might induce COX-2 expression through the activation of NF-kappaB in human osteoblasts. These results suggest that eugenol might be involved in periapical healing by impairing the functions of osteoblasts.

Computer-assisted evaluation of microleakage after apical resection with laser and conventional techniques

The purpose of this in vitro study was to observe the morphological changes and apical dye penetration at apical dentin surfaces after apicoectomy with conventional techniques and laser beam. Sixty single-rooted extracted teeth were selected for the study. The crowns were resected below the cemento-enamel junction. Then, these teeth were treated endodontically and filled with gutta-percha using AH-26 root canal sealer. The teeth were randomly divided into four groups of 15 teeth in each. The roots were resected perpendicular to its long axis 3 mm from the apex using Er: yttrium-aluminium-garnet (YAG) laser irradiation in groups 1 and 2, and the resected root surfaces were lased with Nd:YAG laser in group 2. The apexes were resected by a high-speed handpiece in groups 3 and 4, and the resected root surfaces were lased with Nd:YAG laser in group 4. Ten teeth in each group were used for leakage studies, and the other five teeth were used for scanning electron microscopic examinations. Seven sections were obtained from each root to assess the microleakage, and the sections were analyzed in a computer-assisted manner. No statistically significant differences were observed between the leakage percentage of groups 1 and 3 and groups 2 and 4 (p>0.05). Morphological differences were observed between apical dentin surfaces resected with conventional techniques and laser beam.

Lysanda paste: a new option for root-end filling

This study aimed to compare the apical sealing of root-end fillings performed with Lysanda (zinc oxide-eugenol paste) with radiopacifiers (iodoform or zinc oxide) and calcium hydroxide. Root-end cavities were prepared and filled with different materials, as follows: Group I - Lysanda paste with iodoform; Group II - Lysanda paste with iodoform and calcium hydroxide; Group III - Lysanda paste with iodoform and zinc oxide; Group IV - Lysanda paste with zinc oxide; Group V - mineral trioxide aggregate (MTA). After filling, the teeth were immersed in 2% methylene blue for analysis of marginal leakage. It was observed that marginal leakage occurred in all groups. Lysanda paste with iodoform showed the lowest leakage, with no statistically significant difference compared to the other groups. All materials can be considered as good options for root-end filling.

Metrologic Evaluation of the Surface of White MTA After the Use of Two Endodontic Irrigants

This study examined the effects of calcium-depleting endodontic irrigants, ethylenediamine tetra-acetic acid (EDTA) and BioPure MTAD, on the dissolution, surface characteristics, and ultrastructural characteristics of white mineral trioxide aggregate (MTA). The latter was mixed in a 0.35 water-cement ratio, condensed into cylindrical wells created in Plexiglas platforms, and allowed to harden completely before initial treatment with 1.3% NaOCl and final treatments with either 17% EDTA for 5 minutes, or BioPure MTAD for 1, 3, or 5 minutes. Analysis of the mean depths of material removed using three-dimensional profilometry revealed significantly more material removed by BioPure MTAD. Although these minor depth changes (<10 microm) are unlikely to cause clinical concern, the BioPure MTAD-treated MTA surfaces exhibited higher surface roughness and with more calcium extracted when compared with EDTA treatment. Decomposition of particle-binding hydration phases by acid corrosion raises potential concern on the strength and sealing properties of MTA-repaired perforations following final irrigation by BioPure MTAD.

Monoblocks in root canals: a hypothetical or a tangible goal

The term monoblock has become familiar in the endodontic literature with recent interest in the application of dentin adhesive technology to endodontics. Endodontic monoblocks have generated controversial discussions among academicians and clinicians as to whether they are able to improve the quality of seal in root fillings and to strengthen roots. This review attempts to provide a broader meaning to the term monoblock and to see how this definition may be applied to the materials that have been used in the past and present for rehabilitation of the root canal space. The potential of currently available bondable materials to achieve mechanically homogeneous units with root dentin is then discussed in relation to the classical concept in which the term monoblock was first employed in restorative dentistry and subsequently in endodontics.

Randomized controlled trial of mineral trioxide aggregate and formocresol for pulpotomy in primary molar teeth

AIM

To compare the outcome after 6 months of the application of formocresol (FC) or mineral trioxide aggregate (MTA) during pulpotomy in primary molar teeth.

METHODOLOGY

A maximum of 126 children (aged 5-9 years) with carious primary teeth that required pulpotomy were selected. Following randomization, a standard pulpotomy preparation was undertaken, and the coronal pulp removed and bleeding arrested. In the FC group, cotton balls, soaked in FC, were placed for 5 min, and then the pulp chamber was filled with Zonalin, a pulpotomy agent. In the MTA group, a 1-mm-thick paste of MTA was used as a pulpotomy agent. The crowns in both groups were restored with amalgam or glass ionomer. The teeth of 100 patients were evaluated and compared clinically and radiographically after 3 and 6 months.

RESULTS

No signs of clinical failure were observed at the 3- and 6-month follow-up appointments in either group. There were no significant differences in the radiographic findings of the teeth and surrounding tissue at the 3-month follow-up. However, at the 6-month follow-up, significantly more cases (P = 0.036) with root resorption were seen in the FC group; no cases of resorption occurred amongst the MTA cases. The surrounding tissue showed radiographic signs of post-treatment disease in four FC cases; none was seen in the MTA cases.

CONCLUSION

After 6 months, pulpotomy with MTA was associated with fewer cases of root resorption and post-treatment disease. MTA appears to be a reliable alternative material for pulpotomy in primary molar teeth.

Treatment of lateral root perforation with mineral trioxide aggregate: a case report

Root perforations are undesired complications of endodontic treatment which result in loss of integrity of the root and further destruction of the adjacent periodontal tissues. In recent literature mineral trioxide aggregate (MTA) has been regarded as an ideal material for perforation repair. In this case iatrogenic perforation was observed in a maxillary central incisor. It was not possible to reach the perforation from the access cavity due to the angulation and excessive bleeding even though the root canal was filled with calcium hydroxide paste between appointments. Therefore, surgical intervention was preferred. After the root canal was filled with gutta percha and AH plus, the perforation site was subsequently sealed with MTA. The restoration was made with strip crown and composite resin. The symptoms were ceased and the results were satisfactory after 15 months follow-up.

Mineral trioxide aggregate: a review of the constituents and biological properties of the material

This paper reviews the literature on the constituents and biocompatibility of mineral trioxide aggregate (MTA). A Medline search was conducted. The first publication on the material was in November 1993. The Medline search identified 206 papers published from November 1993 to August 2005. Specific searches on constituents and biocompatibility of mineral trioxide aggregate, however, yielded few publications. Initially all abstracts were read to identify which fitted one of the two categories required for this review, constituents or biocompatibility. Based on this assessment and a review of the papers, 13 were included in the constituent category and 53 in the biocompatibility category. Relatively few articles addressed the constituents of MTA, whilst cytological evaluation was the most widely used biocompatibility test.

Modern Endodontic Surgery Concepts and Practice: A Review

Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipment, instruments and materials that match biological concepts with clinical practice, we believe that microsurgical approaches produce predictable outcomes in the healing of lesions of endodontic origin. In this review we attempted to provide the most current concepts, techniques, instruments and materials with the aim of demonstrating how far we have come. Our ultimate goal is to assertively teach the future generation of graduate students and also train our colleagues to incorporate these techniques and concepts into everyday practice.

The effects of various additives on setting properties of MTA

Delayed setting times may limit the use of mineral trioxide aggregate (MTA) in endodontic procedures. The purpose of this study was to identify types and amounts of MTA additives to enhance its setting properties. Additives tested include saline, 2% lidocaine, 3.0% NaOCl gel, chlorhexidine gluconate gel, K-Y Jelly, 3% and 5% CaCl2. The setting times were evaluated using a Vicat apparatus; compressive strengths of set materials were evaluated with an Instron machine. NaOCl gel, K-Y Jelly and 5% CaCl2 decreased the setting time to 20 to 25 min; compressive strengths of these set materials were significantly lower than MTA mixed with water (p < 0.05). Because MTA mixed with NaOCl gel demonstrated good working properties and improved setting time, this combination may be a viable option in single visit procedures where compressive strength of the material is not a critical issue.