Fracture resistance of simulated immature teeth after apexification with calcium silicate-based materials

Clinical applications of calcium silicate-based materials: a narrative review

Calcium silicate-based materials are hydrophilic materials with biocompatibility and bioactivity properties. Despite many advantages, they might present some problems related to discolouration, setting time, manipulation and solubility depending on the composition of the product and the type of clinical application. Calcium silicate-based materials can be evaluated under two types according to their intended use: calcium silicate-based cements (CSCs) and calcium silicate-based sealers (CSSs). CSCs can be used in many endodontic procedures including perforation repair, resorption repair, apical barriers, guided endodontic repair, vital pulp treatment, endodontic surgery, root fractures and root canal filling as a core obturation material. CSSs are available for use with gutta-percha to obturate root canals using cold and warm techniques, including the sealer-based obturation technique. The purpose of this review is to evaluate the available literature on CSCs and CSSs and to provide up-to-date information and recommendations for their clinical applications.

Bioceramics in Endodontics: Updates and Future Perspectives

Bioceramics, with excellent bioactivity and biocompatibility, have been widely used in dentistry, particularly in endodontics. Mineral trioxide aggregate (MTA) is the most widely used bioceramic in endodontics. Recently, many new bioceramics have been developed, showing good potential for the treatment of endodontic diseases. This paper reviews the characteristics of bioceramics and their applications in various clinical endodontic situations, including root-end filling, root canal therapy, vital pulp therapy, apexification/regenerative endodontic treatment, perforation repair, and root defect repair. Relevant literature published from 1993 to 2023 was searched by keywords in PubMed and Web of Science. Current evidence supports the predictable outcome of MTA in the treatment of endodontic diseases. Although novel bioceramics such as Biodentine, EndoSequence, and calcium-enriched mixtures have shown promising clinical outcomes, more well-controlled clinical trials are still needed to provide high-level evidence for their application in endodontics. In addition, to better tackle the clinical challenges in endodontics, efforts are needed to improve the bioactivity of bioceramics, particularly to enhance their antimicrobial activity and mechanical properties and reduce their setting time and solubility.

Treatment of Peri-Invagination Lesion and Vitality Preservation in Type III Dens Invaginatus in Bilateral Immature Maxillary Lateral Incisors: A Case Report

The superior lateral incisors are primarily affected by the developmental deformity known as dens invaginatus (DI). Oehler's type III DI has the highest complexity rendering a root canal treatment (RCT) an arduous challenge for this type, so early diagnosis and treatment before pulp involvement are important. This report presents two maxillary lateral incisors with type IIIb DI, the left one being associated with a periapical lesion and the right one with normal pulp. A nine-year-old boy was referred to our clinic complaining of mobility of the maxillary left lateral incisor (LLI) associated with gumboil throughout the previous two months. Periapical radiolucency was visible on radiographs, as well as an invagination that crosses the apical foramen from the pulp chamber in both maxillary lateral incisors. The pulp of the main canal of LLI was vital and pseudo canals were necrotized and associated with chronic apical abscess. Based on the condition of the main pulp of maxillary lateral incisors, two separate treatments were carried out. RCT was done only for the pseudo canals in the LLI, while the main root canal was preserved. The right maxillary lateral incisor (RLI) had vital pulp with normal periapical tissue So the invagination was sealed as the tooth was erupting. During the one-year follow-up period, the development of the root in LLI with a thick root wall and closed apex was observed in the periapical radiograph but pseudo canals became infected and the tooth became symptomatic, therefore retreatment for pseudo canals was carried out. The RLI root was developed and the tooth was clinically asymptomatic, so it didn't need further treatment. Maintaining pulp vitality is crucial for type III Dens invaginated young permanent teeth since it could support root formation and improve long-term prognosis, and in cases with pulp involvement, non-surgical RCT is clinically predictable.

The Understanding of Vital Pulp Therapy in Permanent Teeth: A New Perspective

The indications of vital pulp therapy (VPT) are expanding, which cases are suitable for VPT, and how to improve the success rate of VPT is a problem that often bothers us. The main purpose of VPT is to eliminate pulpitis by promoting the formation of reparative dentin or calcium bridge, so that it can continue to perform various physiological functions, and finally achieve the purpose of preserving pulp vitality and long-term preservation of affected teeth. Pulp capping and pulpotomy are the most common methods for VPT. The research field of VPT has attracted the attention of many scholars, who have studied it from many aspects (such as indications, material selection, operation requirements, and long-term prognosis). This article reviews the recent advances in the techniques of VPT in permanent teeth.

Long-term outcome of nonvital immature permanent teeth treated with apexification and corono-radicular adhesive restoration - a case series

INTRODUCTION

This study aims to evaluate the long-term outcome of sixteen permanent maxillary central incisors with nonvital pulps and open apices treated with apexification and corono-radicular adhesive restorations, within a follow-up span of 5 to 22 years.

METHODS

Fourteen patients providing a total of sixteen teeth treated with MTA (n = 12), Biodentine (n = 3) or β-tricalcium phosphate (n = 1) apical barrier and corono-radicular restoration, with or without fiberglass post, were included. Clinical and radiographic criteria were defined for assessment at recall. Restoration and periapical tissues' status evaluation were performed according to FDI World Dental Federation's esthetic, functional and biological criteria and Ørstavik Periapical Index (PAI). Outcome was dichotomized in "healed" (PAI ≤ 2, asymptomatic with absence of signs of infection) or "not healed" (PAI ≥ 3, presence of clinical signs and/or symptoms).

RESULTS

Fourteen out of twenty-four patients were available for the present study (recall rate = 58%). Within a follow-up of 5 to 22 years, ten (62.5%) teeth were considered "healed", fulfilling both strict clinical and radiographic success criteria. Only one tooth was missing due to root resorption and one patient was presenting with clinical signs and symptoms at recall, resulting in a survival rate of 93.8%.

CONCLUSIONS

Adhesive corono-radicular restoration in nonvital permanent immature teeth treated with apexification allows for favorable long-term outcomes, by ensuring structural reinforcement and coronal microleakage prevention. Teeth sustaining a substantial loss of coronal structure may require post/core placement. In the case of failure, this endodontic-restorative combination assured teeth survival until growth phase conclusion, thus allowing for proper prosthetic rehabilitation approaches.

Radiographic differences observed following apexification vs revascularization in necrotic immature molars and incisors: a follow-up study of 18 teeth

PURPOSE

To evaluate the effectiveness of apexification versus revascularization in the treatment of necrotic immature teeth and determine which strategy affords the greatest radiological success rate.

METHODS

An analysis was made of 18 teeth subjected to mineral trioxide aggregate (MTA) apical plugging and regenerative endodontic treatment, assessing healing of the apical lesions and the changes in root dimensions.

RESULTS

Significantly greater root growth was observed with revascularization in terms of the percentage change in length (12.75% at 6 months) and dentin thickness (34.57% at 6 months) (p < 0.05). There were no significant differences between the two treatments in terms of the apical healing scores after 6 months of follow-up (p > 0.05).

CONCLUSION

Apexification with an MTA apical plug and pulp regeneration are reliable treatments for non-vital immature teeth. The radiographic outcomes are comparable between the immature teeth subjected to MTA apexification versus those subjected to revascularization. The results of the present study indicate a greater increase in root length and width with regenerative endodontic treatment.

Fracture Resistance of Simulated Immature Teeth Reinforced with Different Mineral Aggregate-Based Materials

This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.

Effect of MTA versus CEM apical plugs on fracture resistance of endodontically treated simulated immature teeth restored with cast metal posts: an in-vitro study

BACKGROUND

Endodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different apical plug materials (MTA and Calcium enriched mixture cement) at varied thicknesses on fracture resistance of teeth restored with cast metal posts.

METHODS

A total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups (n = 8) according to apical plug (control group: No plug, group MTA5: 5 mm MTA plug, group CEM5: 5 mm CEM plug, group MTA3: 3 mm MTA plug, group CEM3: 3 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using One-way ANOVA and Dunnett's T3 tests with significance level at P value < 0.05.

RESULTS

The analysis showed a significant difference of fracture resistance between groups (P value < 0.05). The mean fracture resistance of samples in control group was significantly lower than MTA5 (P value = 0.003). There was no significant difference between other groups (P value > 0.05).

CONCLUSIONS

Within the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 3 mm MTA apical plug or either 3 or 5 mm CEM apical plug.

Effect of mineral trioxide aggregate and biodentine™ on fracture resistance of immature teeth dentine over time: in vitro study

PURPOSE

The aim of this in vitro study was to evaluate the effect of root filling with White Mineral Trioxide Aggregate (WMTA) and Biodentine™ (BD) on the fracture resistance of simulated immature teeth over different time periods.

METHODS

Sixty sound-extracted human single-rooted premolars were randomly allocated into 3 groups, 2 experimental and 1 control group, with 20 teeth each. Simulation of roots into immature apices were done using Peeso reamers. After preparation, the root canals of teeth in the experimental groups were completely filled with either WMTA or BD. The control group was subdivided into positive controls (n = 10) which received no treatment and negative controls (n = 10) which were prepared the same way and filled with normal saline. The specimens were subjected to fracture testing using a universal testing machine after 2 weeks and 3 months. The peak load to fracture and the fracture location were recorded.

RESULTS

Regarding fracture resistance, the MTA group had the highest fracture resistance at 2 weeks testing, while at 3 months there was no significant difference between the groups (P > 0.05). Regarding fracture location, at 2 weeks there was no significant difference in the fracture location between the groups, while at 3 months, the difference was significant (P < 0.05), the middle root fracture being the most frequent (63.3%).

CONCLUSION

No significant difference in fracture resistant of simulated immature teeth was observed after 3 months when they were filled with Biodentine or WMTA, indicating that Biodentine could be a suitable substitute for MTA. There was no difference in the possible fracture location at 2 weeks, while after 3 months middle root fractures were more frequent.

Fracture resistance of human roots filled with mineral trioxide aggregate mixed with phosphate-buffered saline, with and without calcium hydroxide pre-medication

AIM

To compare the fracture strength of extracted human roots with apical plugs of mineral trioxide aggregate (MTA) mixed with either Ca- and Mg-free phosphate-buffered saline (PBS) or water, with and without calcium hydroxide (CH) canal pre-medication.

METHODOLOGY

A total of 180 single-rooted human teeth were prepared to resemble immature roots and divided into groups (n = 20). The negative control received canal irrigation only, and the positive control received intracanal treatment with CH for either two or twelve weeks. MTA mixed with water was used in Group 1: (i) without CH pre-medication - MTA(W); (ii) after 2 weeks CH pre-medication - 2/52CH + MTA(W); and (iii) after 12-week CH pre-medication - 12/52 CH + MTA(W). MTA mixed with PBS was used in Group 2: (i) without CH pre-medication - MTA(PBS); (ii) after 2-week CH pre-medication - 2/52CH + MTA(PBS); and (iii) after 12-week CH pre-medication - 12/52 CH + MTA(PBS). A compressive force was applied to each root until the point of fracture. The results were analysed by the Kruskal-Wallis and Dunn's multiple comparisons tests (P < 0.05).

RESULTS

There was no significant difference between groups MTA(W), MTA(PBS) and 2/52CH + MTA(PBS), and all three groups were significantly (P < 0.01, P < 0.05 and P < 0.05, respectively) more resistant to fracture than the negative control. Within Group 1, the samples that received two- (P < 0.01) and twelve-week (P < 0.001) CH pre-treatment were more prone to fracture than those which did not. No difference was found amongst the control groups. The roots of the MTA(PBS) group had a higher dependability (P < 0.05) than the MTA(W) group when compared by the Weibull modulus. The difference was also present when a 2-week CH pre-medication was used.

CONCLUSIONS

Mineral trioxide aggregate mixed with Ca- and Mg-free phosphate-buffered saline had a significant strengthening effect on the fracture resistance of structurally weak roots, even when short-term calcium hydroxide pre-medication had been used. MTA mixed with water lost its strengthening effect on human roots when 2- or 12-week CH pre-treatment had been used. Use of CH dressing for up to 12 weeks had no negative effect on fracture resistance of human roots.

Biodentine™ material characteristics and clinical applications: a 3 year literature review and update

INTRODUCTION

Biodentine™ has frequently been acknowledged in the literature as a promising material and serves as an important representative of tricalcium silicate based cements used in dentistry.

AIM

To provide an update on the physical and biological properties of Biodentine™ and to compare these properties with those of other tricalcium silicate cements namely, different variants of mineral trioxide aggregate (MTA) such as ProRoot MTA, MTA Angelus, Micro Mega MTA (MM-MTA), Retro MTA, Ortho MTA, MTA Plus, GCMTA, MTA HP and calcium enriched mixture (CEM), Endosequence and Bioaggregate™.

STUDY DESIGN

A comprehensive literature search for publications from November 20, 2013 to November 20, 2016 was performed by two independent reviewers on Medline (PubMed), Embase, Web of Science, CENTRAL (Cochrane), SIGLE, SciELO, Scopus, Lilacs and clinicaltrials.gov. Electronic and hand search was carried out to identify randomised control trials (RCTs), case control studies, case series, case reports, as well as in vitro and animal studies published in the English language.

CONCLUSIONS

The enhanced physical and biologic properties of Biodentine™ could be attributed to the presence of finer particle size, use of zirconium oxide as radiopacifier, purity of tricalcium silicate, absence of dicalcium silicate, and the addition of calcium chloride and hydrosoluble polymer. Furthermore, as Biodentine™ overcomes the major drawbacks of MTA it has great potential to revolutionise the different treatment modalities in paediatric dentistry and endodontics especially after traumatic injuries. Nevertheless, high quality long-term clinical studies are required to facilitate definitive conclusions.

Alkaline Material Effects on Roots of Teeth

The aim of this review was to identify and analyse all studies related to the effects of alkaline materials used in dentistry on roots of teeth. The first part of the review focused on mechanical property alterations of root dentine due to sodium hypochlorite (SH) used as an irrigant solution based on MeSH (Medical Subject Heading) terms from a previous study by Pascon et al in 2009. The second part reviewed literature on calcium hydroxide (CH), mineral trioxide aggregate (MTA) and other alkaline materials used as root canal dressings or filling materials. Additional MeSH terms used included "compressive strength", "elastic modulus" "flexural strength", "fracture strength" and "fracture resistance". The language filter was English. Of the initial 205 articles identified, 49 were included in this review, of which 29 were on SH, 21 on CH/MTA, and 1 relating to both. Many in vitro studies indicated a strong link between reduced mechanical properties of roots of teeth or radicular dentine treated with SH, and when sealers or root fillings with CH- or MTA-based materials were placed in contact with roots or radicular dentine. Recent literature indicates that the association between reduced mechanical properties and alkaline sealers and/or root-filling materials is not as straightforward as previously assumed, and requires further investigation using more valid experimental models.