Pulpless Teeth Research Articles

In vitro treatment of Enterococcus faecalis with calcium hydroxide impairs phagocytosis by human macrophages

Objective: Monocyte-derived macrophages (MDMs) ability to phagocytize and produce nitric oxide (NO) was tested against root-canal strains of Enterococcus faecalis submitted to alkaline stress. Root-canal strains were also compared with urine Enterococci.Materials and Methods: Enterococcus faecalis were stressed with alkaline-BHI broth and incubated in vitro at a cell/bacteria ratio of 1:5. Phagocytosis was analyzed by fluorescence microscopy using acridine orange stain, and NO concentration was measured in supernatants.Results and Conclusions: Alkaline-stress significantly impaired MDMs phagocytosis of E. faecalis strains analyzed, except in ATCC4083 isolated from a pulpless tooth, but NO production was unchanged. Comparison of different strains showed the urine isolate had higher NO levels than root canal strains. Alterations in the bacterial cell wall structures after alkaline-stress possibly made bacteria less recognizable and phagocytized by MDMs but did not affect their ability to activate NO production. Furthermore, root canal strains elicited different responses by immune cells compared with strains from urine. Clinically, impaired phagocytosis of E. faecalis could contribute to their persistence in root canal systems previously treated with calcium hydroxide.

Evaluation of static fracture resistances and patterns of pulpless tooth restored with poly-ether-ketone-ketone (PEKK) post

Evaluation of static fracture resistances and patterns of pulpless tooth restored with poly-ether-ketone-ketone (PEKK) post

Pulp Regeneration by 3-dimensional Dental Pulp Stem Cell Constructs

Dental pulp regeneration therapy for the pulpless tooth has attracted recent attention, and clinical trial studies are underway with the tissue engineering approach. However, there remain many concerns, including the extended period for regenerating the dental pulp. In addition, the use of scaffolds increases the risk of inflammation and infection. To establish a basic technology for novel dental pulp regenerative therapy that allows transplant of pulp-like tissue, we attempted to fabricate scaffold-free 3-dimensional (3D) cell constructs composed of dental pulp stem cells (DPSCs). Furthermore, we assessed viability of these 3D DPSC constructs for dental pulp regeneration through in vitro and in vivo studies. For the in vitro study, we obtained 3D DPSC constructs by shaping sheet-like aggregates of DPSCs with a thermoresponsive hydrogel. DPSCs within constructs remained viable even after prolonged culture; furthermore, 3D DPSC constructs possessed a self-organization ability necessary to serve as a transplant tissue. For the in vivo study, we filled the human tooth root canal with DPSC constructs and implanted it subcutaneously into immunodeficient mice. We found that pulp-like tissues with rich blood vessels were formed within the human root canal 6 wk after implantation. Histologic analyses revealed that transplanted DPSCs differentiated into odontoblast-like mineralizing cells at sites in contact with dentin; furthermore, human CD31–positive endothelial cells were found at the center of regenerated tissue. Thus, the self-organizing ability of 3D DPSC constructs was active within the pulpless root canal in vivo. In addition, blood vessel–rich pulp-like tissues can be formed with DPSCs without requiring scaffolds or growth factors. The technology established in this study allows us to prepare DPSC constructs with variable sizes and shapes; therefore, transplantation of DPSC constructs shows promise for regeneration of pulpal tissue in the pulpless tooth.

Role of Antibiotics as Intracanal Medicament-A Literature Review

Antibiotics are an extremely valuable addition to the armamentarium available to health practitioners for management of bacterial infections. Due to the potential risk of adverse systemic effects of systemic applications and ineffectiveness of systemic antibiotics in the necrotic pulpless tooth and the periradicular tissues, local application of antibiotics will be more effective since it is directly acting against the microorganism in the infected root canal. This paper reviews the applications of antibiotics and antibiotics containing medicaments in endodontics.

Частота встречаемости оттенков депульпированных зубов с применением дополнительных эталонов к шкале VITA

Частота встречаемости оттенков депульпированных зубов с применением дополнительных эталонов к шкале VITA

Determination of pulp necrosis based on periapical digital radiography histogram and pulp histopathology

Introduction: Radiographic examination is needed to determine the diagnosis of pulp necrosis in addition to a clinical examination. Visual observation was limited in seeing the colour change degree and hence an effort taken by assessing the histogram value. The purpose of this study was to obtain the pulp chamber histogram pattern which reveals its grey scale value, trend, intensity average, histogram variation, and histograms maximum regional of interest (ROI) through digital periapical radiograph. Methods: This study was a descriptive study of the total of nine pulp chamber periapical radiograph data samples. The samples were divided into three groups, the 1st group was the data taken prior to the tooth extraction, the 2nd group was the data collected after the teeth extraction, and the 3rd group was the data of priorly pulpless teeth. Results: There was a tendency of histogram graphic shifting to the left side, likely towards the radiolucent area on ROI of the pulp at the apical region, whilst histopathologically, a massive infiltration of a round PMN cells was found in the area. This finding supported the determination of pulp necrosis diagnose. Conclusion: The tooth with a pulp necrosis showed a tendency that led to radiolucency on periapical radiograph histogram, and histopathologic examination showed massive infiltration of a round PMN cells, thus supported the pulp necrosis diagnose.

Management of Non-vital Maxillary Central Incisors with Open Apices by MTA Plugging

The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. An 11 year old boy was presented with pain in his upper anterior teeth. On clinical examination both the maxillary central incisors revealed slight discoloration and fracture of the crown. Radiographic evaluation revealed radiolucency and open apices of both central incisors. Apexification with MTA apical plug was carried out before obturation with gutta-percha and sealer and the treatment was completed within 3 consecutive appointments. In twelve months follow up both the teeth were clinically and radiographically asymptomatic and the healing of the apical area was continued. The positive clinical outcome may encourage the future use of mineral trioxide aggregate (MTA) as an apical plug material in case of non-vital open apex teeth.J Bangladesh Coll Phys Surg 2017; 35(4): 196-199

Tensile stress distribution in maxillary central incisors restored with cast-made and prefabricated dental posts.

Abstract: Aim: To analyze and compare the tensile stress distribution in endodontically treated teeth restored with cast-made (Ni-Cr and gold) and prefabricated (titanium and glass fibre) dental posts. Methodology: Four three-dimensional finite element (FE) models of a maxillary central incisor restored with Ni-Cr cast-made (Model Ni-Cr), gold cast-made (Model GO), prefabricated titanium (Model TI) and prefabricated glass fibre (Model FP) posts were constructed. An oblique loading of 100N was applied to each three-dimensional model. Tensile stress distribution within the root dentine and at the post and surrounding structure interfaces were analysed. Results: In all the FE models studied, a higher magnitude of tensile stresses was observed on the palatal aspect of the cervical dentin as compared to the labial aspect and progressively decreases from the outer to the inner part of the root. The gold cast-made and glass fibre post models showed significantly less tensile stress concentration in the post-core component than the other experimental models. The maximum tensile stress was seen on the palatal aspect of the Ni-Cr compared to other posts. The higher magnitude interfacial tensile stress concentration was observed in a pulpless tooth restored with a Ni-Cr cast-made post, followed by titanium and gold cast-made posts, respectively. However, the minimum interfacial tensile stress was noticed in a pulpless tooth restored with a glass fibre post. Conclusion: Glass fibre posts tend to transfer tensile stress more homogenously within the tooth and at interfaces than the other types of investigated posts.

Clinical performance and failure modes of pulpless teeth restored with posts: a systematic review.

The aim of this systematic review was to compare the clinical performance and failure modes of teeth restored with intra-radicular retainers. A search was performed on PubMed/Medline, Central and ClinicalTrials databases for randomized clinical trials comparing clinical behavior and failures of at least two types of retainers. From 341 detected papers, 16 were selected for full-text analysis, of which 9 met the eligibility criteria. A manual search added 2 more studies, totalizing 11 studies that were included in this review. Evaluated retainers were fiber (prefabricated and customized) and metal (prefabricated and cast) posts, and follow-up ranged from 6 months to 10 years. Most studies showed good clinical behavior for evaluated intra-radicular retainers. Reported survival rates varied from 71 to 100% for fiber posts and 50 to 97.1% for metal posts. Studies found no difference in the survival among different metal posts and most studies found no difference between fiber and metal posts. Two studies also showed that remaining dentine height, number of walls and ferrule increased the longevity of the restored teeth. Failures of fiber posts were mainly due to post loss of retention, while metal post failures were mostly related to root fracture, post fracture and crown and/or post loss of retention. In conclusion, metal and fiber posts present similar clinical behavior at short to medium term follow-up. Remaining dental structure and ferrule increase the survival of restored pulpless teeth. Studies with longer follow-up are needed.

The Pulpless Tooth: A Case of Calcified Pulp Canal

The Pulpless Tooth: A Case of Calcified Pulp Canal

Fabrication of cast post and core by a modified indirect procedure and postcementation using a novel technique

The restoration of endodontically treated pulpless teeth is a challenging dental procedure. Post and core is indicated in cases of extensive coronal tooth destruction where additional retention is required. The post is used to retain a core that can be used to retain definitive prosthesis. The choice between using a cast post and a prefabricated post depends on multiple factors such as canal configuration and remaining tooth structure. It has been said that if a canal requires extensive preparation, a well-adapted cast post and core will be more retentive than a prefabricated post that does not match the canal configuration. The cast post and core is fitted to the prepared root canal space and designed to resist torsional forces. However, one drawback of cast post is its tedious and time-consuming wax pattern technique. In this case report, we have used a time saving modified indirect technique for fabricating cast post and core, without the use of any reinforcement, no wax, no pattern resin but only rubber base impression material along with a novel technique of cementation, which utilizes a modified syringe with needle to facilitate even distribution of luting cement within the canal.

Aetiological, histopathological, clinical, diagnostic and therapeutical features of idiopathic cervical resorption

Root resorption is the loss of hard dental tissue as a result of odontoclastic action involving vital and pulpless teeth. Cervical root resorption (CRR) is a type of external resorption which usually occurs immediately below the epithelial attachment of the tooth in the cervical region. The idiopathic cervical resorption (ICR) refers to a clinical situation in which all other causes, whether local or systemic, have been ruled out as the origin of the disease. The early stage is asymptomatic and might be diagnosed by a routine radiograph or a clinical examination. In this study, the aetiological, histological, clinical and radiological analysis is undertaken; a review is made concerning the pathologies to which the differential diagnosis should be applied; and the different therapeutical options are discussed. This lesion sometimes demands the management of a broad field of multidisciplinary techniques such as restorative dentistry, endodontics, surgery, implants and prosthesis. Clinical relevance: Cone-beam computed tomography (CBCT) may be a useful tool to determine the true extent of external cervical resorption lesions.

Odontoblasts: Specialized hard-tissue-forming cells in the dentin-pulp complex.

Odontoblasts are specialized cells that produce dentin and exhibit unique morphological characteristics; i.e., they extend cytoplasmic processes into dentinal tubules. While osteoblasts, which are typical hard-tissue-forming cells, are generated from mesenchymal stem cells during normal and pathological bone metabolism, the induction of odontoblasts only occurs once during tooth development, and odontoblasts survive throughout the lives of healthy teeth. During the differentiation of odontoblasts, signaling molecules from the inner enamel epithelium are considered necessary for the differentiation of odontoblast precursors, i.e., peripheral dental papilla cells. If odontoblasts are destroyed by severe external stimuli, such as deep caries, the differentiation of dental pulp stem cells into odontoblast-like cells is induced. Various bioactive molecules, such as non-collagenous proteins, might be involved in this process, although the precise mechanisms responsible for odontoblast differentiation have not been fully elucidated. Recently, our knowledge about the other functional activities of odontoblasts (apart from dentin formation) has increased. For example, it has been suggested that odontoblasts might act as nociceptive receptors, and surveillance cells that detect the invasion of exogenous pathogens. The regeneration of the dentin-pulp complex has recently gained much attention as a promising future treatment modality that could increase the longevity of pulpless teeth. Finally, congenital dentin anomalies, which are concerned with the disturbance of odontoblast functions, are summarized.

Remaining coronal dentin and risk of fiber-reinforced composite post-core restoration failure: a meta-analysis.

The amount of coronal residual structure has been recognized as critical to the survival probability of pulpless teeth. The aim of this study was to analyze whether and how coronal dentin loss would affect the failure rate of fiber-reinforced composite (FRC) post-core restorations. Eligible studies were searched in PubMed, Cochrane Library, Embase, and China National Knowledge Infrastructure databases from their inception through April 2014. The risk ratio with 95% confidence interval (CI) was estimated using the Mantel and Haenszel method. Five studies were included in this meta-analysis. The risk ratio for coronal wall absence was 2.73 (95% CI: 1.48-5.03). The risk ratio for ferrule absence was 1.94 (95% CI: 0.57-6.54). This meta-analysis of the limited studies available suggested that coronal wall absence might increase the risk of FRC post-core restoration failure, while the role of ferrule effect is still not entirely understood.

Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth.

To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth. Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks. The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex. Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

Effect of two contemporary root canal sealers on root canal dentin microhardness.

BackgroundSuccessful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and MethodsForty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen.ResultsFour way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). ConclusionsRoot canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic.

The use of a fiber sleeve to improve fracture strength of pulpless teeth with flared root canals

ObjectivesThis study aimed to investigate how use of a fiber sleeve may reduce interfacial debonding and improve fracture strength of pulpless teeth with flared root canals. MethodsPulpless premolars with flared root canals were restored either with a fiber-reinforced post (FRP) alone or with an FRP wrapped in a hollow tubular fiber sleeve. A normal root restored with an FRP alone served as a control. The integrity of resin–dentin and resin–fiber interfaces in the restored roots was evaluated by a stereoscopic system after penetrating a dye. Four roots were tested for each experimental group. Fracture resistance in pulpless premolars with flared root canals restored with an FRP alone or with an FRP/sleeve combination were investigated under bonded and non-bonded conditions with static fracture testing (n=8), and stress distribution in these restored premolars were tested by finite element analysis (FEA). ResultsFlared root canals restored with an FRP/sleeve combination demonstrated superior integrity at the cervical resin–dentin interface to root canals with an FRP alone. Premolars with a flared root canal restored with an FRP/sleeve combination showed significantly greater fracture resistance compared with premolars restored with an FRP alone. FEA showed that once interfacial de-bonding extended to the cervical region of the root, stress concentration in the root dentin dramatically increased. SignificanceThe FRP/sleeve combination was effective in reducing debonding and, hence, improving the fracture strength of pulpless premolars with flared root canals.

Periapical repair and apical closure of a pulpless tooth using calcium hydroxide-A case report

Aim : To report the induction of apical root development by calcium hydroxide in teeth with pulp necrosis and periapical radiolucency. Method and Materials : Two cases were presented where the calcium hydroxide and iodoform paste Metapex® was placed in the root canals of immature permanent teeth using disposable plastic tips. The teeth involved were evaluated radiographically at regular intervals for the first 12 months after placement of the paste. At the end of 12 months both the cases showed continued root growth and apical closure (apexification) with no evidence of periapical pathology. Conventional endodontic treatment was then performed. Results : In both the clinical cases presented, a combination of calcium hydroxide and iodoform paste (Metapex®) was used and showed promising results in inducing root-end growth and closure after 12 months. Conclusion : In these two clinical cases, the calcium hydroxide and iodoform paste Metapex® (Meta Biomed Co. Ltd., South Korea) was found to induce apical closure when assessed radiographically. Over a period of 12 months both the cases showed continued root growth. Clinical Significance : The calcium hydroxide and iodoform paste Metapex® promoted continued root-end growth with apexification in the nonvital immature permanent teeth treated.

Apexification

AbstractApexification is a method to induce a calcific barrier across an open apex of an immature, pulpless tooth. Apical closure occurs approximately three years after eruption. Traumatic injuries to young permanent teeth before root formation is complete commonly occur in children resulting in open apex. This can be treated by Surgical or Non - Surgical treatment modalities. Non surgical treatment modalities include various methods such as Customized cone, Short fill technique, Apexification with various materials and One visit apexification. Various materials that can be used for apexification include Calcium hydroxide, MTA, Tricalcium phosphate, Dentin chips, Calcium phosphate ceramics and hydroxyapatite and bone morphogenetic proteins. Calcium hydroxide is the most common and traditional material employed for inducing apexification. This is a multi visit technique requiring six months to four years to complete.

Influence of masticatory fatigue on the fracture resistance of the pulpless teeth restored with quartz-fiber post–core and crown

To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post–core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post–core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 mm⋅min−1. The mean destructive force values were (733.88±254.99) and (869.14±280.26) N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups (P>0.05). Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post–core–crown complex.