Pulp revascularization of replanted immature dog teeth after treatment with minocycline and doxycycline assessed by laser Doppler flowmetry, radiography, and histology

Revascularization of a Permanent Tooth with Necrotic Pulp and Apical Periodontitis

This case report details a pulp revascularization treatment administered to a mature permanent tooth exhibiting pulp necrosis. A 22-years old female patient complained of the recurrence of a sinus tract labial of the maxillary right central incisor; which was tender on biting. Diagnosis of pulp necrosis and symptomatic apical periodontitis. Preoperative periapical and CBCT radiographs showed root with wide apical foramen and large apical radiolucency. Pulp revascularization procedure was performed using 1.3% sodium hypochlorite irrigation, 17% Ethylenediaminetetraacetic acid irrigation, and calcium hydroxide intracanal dressing for 2 weeks. During the last visit, intentional bleeding was induced, collagen matrix was set over the blood clot, 2 mm of mineral trioxide aggregate and glass-ionomer filling was placed. A year of follow-up, the tooth showed no signs or symptoms and responded normally to the sensibility tests. Intra-oral periapical radiograph and the CBCT showed significant reduction in the periapical lesion's size, slight reduction in the apical foramen's size, and hard radiopaque material deposition at the root's middle third.

Critical appraisal of the 2020 IADT Guidelines: A personal commentary

The 2020 International Association of Dental Traumatology (IADT) Guidelines feature several important changes in the treatment recommendations for traumatic dental injuries (TDIs) from the previous 2012 iteration of these Guidelines. This evidence-based narrative review aims to provide a detailed appraisal of five specific changes incorporated in the 2020 IADT Guidelines, based on the available literature evidence that may have prompted these changes. The paper discusses three excellent additions/changes to the new Guidelines: (i) inclusion of a core outcome set for reporting TDIs; (ii) more conservative management of primary dentition TDIs including the changed recommendations for radiation exposure and managing primary dentition luxation injuries; and (iii) the changes in the treatment recommendations for permanent dentition avulsion injuries. The paper further debates whether two other changes made in the current IADT Guidelines for-(i) intrusion injuries in immature teeth; and (ii) complicated crown-root fractures in mature teeth-have sufficient evidence to support the changed recommendations.

Regenerative endodontic therapy for external inflammatory lateral resorption following traumatic dental injuries: Evidence assessment of best practices

BACKGROUND

External inflammatory lateral resorption (EILR) following dental trauma is a severe complication that can lead to significant root loss and tooth extraction.

OBJECTIVE

The aim of this project was to review current evidence in the literature on regenerative endodontic therapy (RET) for EILR following traumatic injuries and assess the best treatment practices.

METHODS

Publications appearing in PubMed, from January 1, 2001 to January 9, 2022 were studied. Inclusion criteria were: (a) Publications in English; (b) Publications on RET and EILR; (c) Teeth subjected to dental trauma; and (d) Presence of intracanal bleeding and blood clots. Exclusion criteria were: (a) Conference proceedings; (b) Lectures; (c) Abstracts; and (d) Letters to editor; (e) Non-English publications.

RESULTS

355 publications were analysed. Nine met all inclusion criteria. In 10 (58.8%) teeth, triple antibiotic paste was used for an average of 26 days. Double antibiotic paste was used in 3 (17.6%) teeth for an average of 14 days. In 3 (17.6%) cases, calcium hydroxide (Ca(OH)₂ ) was used for 14 days and negative pressure irrigation was applied once on 1 (6%) tooth.

DISCUSSION

Using RET to treat EILR has some advantages compared to long term CA(OH)₂ dressing. RET requires shorter dressing time compared to CA(OH)₂ . This can significantly improve patient compliance. Additionally, in immature teeth, RET helps to arrest root resorption leading to continued root maturogenesis and revascularization. It is recommended that a meticulous follow-up should be conducted when RET is performed to assure early detection of treatment failure.

CONCLUSIONS

RET appears to be a good treatment modality producing biologic repair and improving prognosis in cases of EILR in post-traumatic tooth/pulp injuries. The key limitation of this study is that all publications included were either case reports or case series that usually tend to report successful outcome.

Clinical Outcome and Comparison of Regenerative and Apexification Intervention in Young Immature Necrotic Teeth-A Systematic Review and Meta-Analysis

This systematic review aimed to evaluate interventions individually and compare the clinical outcome of young, immature teeth treated with regenerative endodontic therapy (RET) and apexification procedure. The protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews), bearing the registration number CRD42021230284. A bibliographic search in the biomedical databases was conducted in four databases—PubMed, CENTRAL, EMBASE and ProQuest—using searching keywords and was limited to studies published between January 2000 and April 2022 in English. The search was supplemented by manual searching, citation screening and scanning of all reference lists of selected paper. The study selection criteria were randomized clinical trial, prospective clinical studies and observational studies. The search found 32 eligible articles, which were included in the study. The quality assessment of the studies was performed using the Cochrane risk of bias tool for randomized control trials and non-randomized clinical studies. The meta-analysis was performed using Review Manager software (REVMAN, version 5). The results indicated that a clinicians’ MTA apexification procedure was more successful compared to calcium hydroxide. In RET, apical closure and overall success rate is statistically same for both apical platelet concentrates (APCs) and blood clots (BC). Both interventions have similar survival rates; however, RET should be preferred in cases where the root development is severely deficient, there is insufficient dentine and the tooth’s prognosis is hopeless even with an apexification procedure.

Present status and future directions: Endodontic management of traumatic injuries to permanent teeth

The prognosis of traumatized teeth depends largely on the fate of the pulp and its treatment. This review aims to update the present status on the endodontic management of traumatic injuries to permanent teeth and to identify relevant research areas that could contribute to an improvement in diagnosis and treatment of traumatized permanent teeth. Future research should pay greater attention to (1) diagnostic methods to assess the perfusion of the pulp and enhance detection of tooth cracks and initial signs of root resorption; (2) improved materials for vital pulp treatment; (3) studies focusing on type and duration of splinting after root fractures; (4) antiresorptive intracanal medication in case of posttraumatic pulp necrosis and infection-related resorption and (5) long-term data on the apical barrier technique compared to revitalization.

Prospective cohort study of regenerative potential of non vital immature permanent maxillary central incisors using platelet rich fibrin scaffold

Regenerative endodontic procedures have gained momentum as a treatment modality of young immature permanent teeth. Literature reports reveal that platelet-rich fibrin (PRF) stimulates growth factors and induces regeneration. This study was undertaken to assess the regenerative potential of non-vital immature permanent maxillary central incisors using PRF with a follow-up for 2 yrs. 19 patients in the age group of 9–25 yrs with immature, non-vital permanent maxillary central incisors (n = 23) with/without signs and/or symptoms of periapical pathosis and open apex were included in this study. In the first appointment, access opening, canal disinfection and triple antibiotic paste placement were done. In the subsequent visit, PRF was prepared and placed inside the canal. Access was sealed with Mineral trioxide aggregate plug and composite. The patient was reviewed up to 24 mths. The mean difference was statistically analyzed using Friedman test followed by Dunn post hoc test and adjusted by Bonferroni correction (p < 0.05). As per AAE guidelines, the primary and secondary goals were achieved. A significant (p < 0.001) gradual increase in the root length, thickness of dentinal walls and decrease in apical diameter were observed. Within the limitations of this study, PRF placement was clinically and radiographically effective in inducing regeneration of non-vital immature permanent teeth.

Doxycycline-Loaded Nitric Oxide-Releasing Nanomatrix Gel in Replanted Rat Molar on Pulp Regeneration

The aim of the present study was to evaluate the effect of doxycycline-loaded NO-releasing nanomatrix gel on pulp regeneration in replantation of avulsed rat teeth. A total of 28 maxillary first molars extracted from rats were replanted. The rats were divided into two groups based on the use of root surface treatment: doxycycline-loaded NO-releasing nanomatrix group and no treatment. Eight weeks after replantation, the rats were sacrificed, and the teeth were evaluated using histomorphometric analysis. On histomorphometric analysis, the NO-releasing nanomatrix group demonstrated a significantly lower grade of pulp inflammation (1.00 ± 1.11, mean ± standard deviation) compared to the no treatment group (2.21 ± 1.25, p = 0.014). NO-releasing nanomatrix group showed a significantly higher grade of pulp regeneration (2.57 ± 0.85, p = 0.012) and significantly lower grade of pulp inflammation (1.00 ± 0.68, p = 0.025) compared to the no treatment group. In conclusion, NO-releasing nanomatrix gel improved pulp regeneration of replanted teeth, though the sample size of this study was rather small. Within the limits of this study, NO-releasing nanomatrix gel can provide more favorable pulpal regeneration despite replantation.

Effect of tetracyclines on pulpal and periodontal healing after tooth replantation: a systematic review of human and animal studies

Background

Pulpal and periodontal healing are two main concerns of delayed replantation of avulsed teeth. The objective of this review was to evaluate the effectiveness of topical and systemic application of tetracyclines on pulpal and periodontal healing after tooth replantation.

Methods

A comprehensive electronic search was conducted in six databases. This systematic review was carried out according to Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

After exclusion of 246 irrelevant papers, 14 animal studies and one human study were included in this review. The human study showed that avulsed permanent teeth treated with doxycycline did not show a better clinical outcome for pulp and periodontal healing compared with treatment with normal saline. As for animal studies, significant more pulpal healing was observed in immature teeth treated with topical doxycycline in two researches, while another one study showed that there is no difference between teeth treated with normal saline and teeth treated with doxycycline. Systemic doxycycline exerted no significant effect on pulpal revascularization illustrated by one research. Only one out of four articles illustrated the positive effect of systemic tetracyclines on periodontal healing. One paper reported that intracanal application of demeclocycline promoted favorable periodontal healing. Two articles showed topical doxycycline contributed to favorable periodontal healing, while five studies showed no significant effect of topical tetracyclines on periodontal healing.

Conclusions

As a result of data heterogeneity and limitations of the studies, the effect of topical or systemic application of tetracyclines on pulpal and periodontal healing is inconclusive. More studies are required to get more clinically significant conclusions.

Pulp healing in immature replanted permanent teeth: A competing risk analysis

BACKGROUND/AIM

Tooth displacement during avulsion causes total rupture of the pulp's neurovascular supply. Revascularization and pulp healing may occur in immature teeth, which gives rise to the recommendation that root canal treatment may not be required. The aim of this study was to evaluate the prognostic factors for the pulp's response after replantation of young permanent teeth.

METHODS

Records from 117 patients with 133 replanted permanent immature teeth were reviewed, and pulp outcomes were classified as healing (hard tissue deposition on the dentinal walls followed by narrowing of the pulp lumen or ingrowth of bone-like tissue inside the pulp canal) or non-healing (pulp necrosis with infection). The effect of clinical and demographic co-variates on the hazards of both outcomes was assessed performing a competing risk model.

RESULTS

Pulp necrosis with infection was diagnosed in 78.2% of the teeth, and healing was observed in 12.8% of the teeth. A total of 12 teeth (9.0%) were censored due to prophylactic removal of the pulp or severe external root resorption caused by eruption of adjacent canines. The cs-Cox model demonstrated that the hazards of pulp healing increased in teeth with extra-alveolar periods <15 min (csHR: 7.83, 95% CI 1.76-34.80, p = .01), while the hazards of pulp necrosis with infection decreased (csHR: 0.31, 95% CI: 0.10-0.92, p = .04). Teeth replanted with Moorrees' stages 4 and 5 of root development had higher hazards of pulp necrosis with infection than teeth with stage 2 of root development (csHR: 2.23, 95% CI 1.11-4.50, p = .03; csHR: 2.89, 95% CI: 1.40-5.95; p = .01).

CONCLUSIONS

Pulp healing rarely occurred after replantation of young permanent teeth being associated with short extra-alveolar periods <15 min. Early stages of root development decreased the hazards of pulp necrosis with infection.

Evaluation of the periodontal and pulpal healing of replanted rat molars with doxycycline root conditioning

Purpose

This study aimed to evaluate periodontal and pulpal healing in replanted rat teeth, preserved under different storage conditions, with or without root conditioning using doxycycline.

Methods

A total of 40 maxillary first molars extracted from 20 Sprague-Dawley rats were stored for different durations under different conditions (5 minutes in dry storage and 60 minutes in Hank's balanced salt solution [HBSS]) and subsequently replanted. The rats were divided into 2 groups based on the use of root surface treatment: the doxycycline group (root surface treated with doxycycline) and the control group (no doxycycline treatment). Eight weeks after replantation, the animals were sacrificed, and the teeth were evaluated using micro-computed tomography (micro-CT) and histomorphometric analysis.

Results

In the micro-CT analysis, the doxycycline group showed the same rate of occurrence of periapical radiolucency as was observed in the control group, but a lower degree of root resorption in teeth replanted after 60 minutes of storage in HBSS (P<0.05). In the histomorphometric analysis, the doxycycline group exhibited no improvement in either pulpal or periodontal healing of the replanted tooth after 5 minutes of dry storage, but showed a lower grade of surface root resorption (1.37±0.77) and inflammatory resorption in the teeth stored for 60 minutes in HBSS (1.33±0.71).

Conclusions

In conclusion, doxycycline improved the periodontal healing of replanted teeth stored for 60 minutes in HBSS, whereas doxycycline did not improve periodontal healing of replanted tooth after 5 minutes of dry storage. Within the limits of this study, doxycycline showed more favorable periodontal healing despite delayed replantation.

Regenerative Endodontic Procedures Using Contemporary Endodontic Materials

Calcium hydroxide apexification and Mineral Trioxide Aggregate (MTA) apexification are classical treatments for necrotic immature permanent teeth. The first tend to fail for lack of compliance given the high number of sessions needed; the second has technical difficulties such as material manipulation and overfilling. With both techniques, the root development is interrupted leaving the tooth with a fragile root structure, a poor crown-to-root ratio, periodontal breakdown, and high risk of fracture, compromising long-term prognosis of the tooth. New scientific literature has described a procedure that allows complete root development of these specific teeth. This regenerative endodontic procedure (REP) proposes the use of a combination of antimicrobials and irrigants, no canal walls instrumentation, induced apical bleeding to form a blood clot and a tight seal into the root canal to promote healing. MTA is the most used material to perform this seal, but updated guidelines advise the use of other bioactive endodontic cements that incorporate calcium and silicate in their compositions. They share most of their characteristics with MTA but claim to have fewer drawbacks with regards to manipulation and aesthetics. The purpose of the present article is to review pertinent literature and to describe the clinical procedures protocol with its variations, and their clinical application.

Applications of sensory and physiological measurement in oral-facial dental pain

Dentists regularly employ a variety of self‐report and sensory techniques to aid in the diagnosis and treatment of tooth‐related disease. Many of these techniques leverage principles borrowed from psychophysics, the quantitative measurement of the relationship between stimuli and evoked sensations, which falls under the larger umbrella of quantitative sensory testing (QST). However, most clinicians fail to meet the bar for what could be considered quantitative sensory testing, and instead focus on qualitative and dichotomous “yes/no” aspects of sensory experience. With our current subjective measurements for pain assessments, diagnosis and treatment of dental pain in young children and individuals (any age) with severe cognitive impairment rely extensively on third‐party observations. Consequently, the limitation of inadequate pain diagnosis can lead to poor pain management. In this review, it discusses mechanisms that underlie acute and chronic dental pain. It details the measurement of somatosensory responses and pulpal blood flow as objective measures of tooth health and pain. It proposes that bridging these varied methodologies will significantly improve diagnosis and treatment of orofacial pain and pathology. It concludes that improving the precision of sensory measurements could yield important improvements in diagnostic challenges in pulpal pathology for noncommunicative and cognitively impaired individuals.

Triple antibiotic paste: momentous roles and applications in endodontics: a review

This study investigated the latest findings and notions regarding ‘triple antibiotic paste’ (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must.

[Vital pulp therapy of damaged dental pulp]

The development of an expert consensus on vital pulp therapy can provide practical guidance for the improvement of pulp damage care in China. Dental pulp disease is a major type of illness that adversely affects human oral health. Pulp capping and pulpotomy are currently the main methods for vital pulp therapy. Along with the development of minimal invasion cosmetic dentistry, using different treatment technologies and materials reasonably, preserving healthy tooth tissue, and extending tooth save time have become urgent problems that call for immediate solution in dental clinics. This paper summarizes the experiences and knowledge of endodontic experts. We develop a clinical path of vital pulp therapy for clinical work by utilizing the nature, approach, and degree of pulp damage as references, defense and self-repairing ability of pulp as guidance, and modern technologies of diagnosis and treatment as means.

Pulp Revascularization- It's your Future Whether you Know it or Not?

Pulpal regeneration after tooth injury is not easy to accomplish. In teeth with immature apices and exposed vital pulp tissue, partial or complete pulpotomy is indicated to preserve pulpal function and allow continued root development. In many cases, injury causes loss of pulp vitality and arrested root development leading to a tooth with poor crown root ratio, a root with very thin walls, an open blunderbuss apex and development of apical pathosis. The ideal treatment in such cases would be to obtain further root development and thickening of dentinal walls by stimulating the regeneration of a functional pulp dentin complex. This outcome has been observed after reimplantation in avulsed immature permanent teeth but has been thought impossible in a necrotic infected tooth. This case series evaluates the efficacy of revascularization procedure in immature, non vital permanent teeth. Pulp regeneration was attempted in four patients at Department of Conservative Dentistry, ESIC Dental College, New Delhi using blood clotting approach. The cases were treated and followed up regularly at regular intervals ranging from 6 months to 3 years to assess the treatment response clinically and radiographically. The patients remained clinically asymptomatic with three out of four patients even responding positively to pulp responsiveness tests. Radiographic examination also revealed increased root formation and thickening of dentinal walls. It was concluded that the triad of a disinfected canal, a matrix (blood clot) in to which new tissue could grow and an effective coronal seal produced the desirable environment for successful revascularization.

Comparison of bleaching efficacy of two bleaching agents on teeth discoloured by different antibiotic combinations used in revascularization

OBJECTIVES

To investigate the whitening effects of different bleaching agents on teeth discoloured by different antibiotic combinations of ciprofloxacin and metronidazole with minocycline, doxycycline, amoxicillin or cefaclor.

MATERIALS AND METHODS

Forty extracted bovine incisors were collected and discoloured with triple antibiotic pastes (TAP) with minocycline, doxycycline, amoxicillin and cefaclor throughout 30 days. The specimens were then randomly divided into two subgroups and each group received different bleaching materials: 35% hydrogen peroxide and sodium perborate. Spectrophotometric measurements were obtained on the buccal surfaces of the crown, firstly in the beginning, then on the 4th, 8th and 12th days after the placement of the bleaching materials. The acceptability threshold was set to 3.5. The ∆E values were calculated and the data was analysed using the repeated measures analysis of variance (P = .05).

RESULTS

All the test groups induced colour changes exceeding the acceptability threshold 30 days after the antibiotic pastes were placed. The 35% hydrogen peroxide was more effective than sodium perborate in the whitening of discoloured teeth by antibiotic pastes (P = .001). The whitening effect after the 8th and 12th days was significantly more than after 4 days of treatment (P <.001). The discolouration caused by the TAP with minocycline and cefaclor showed greater whitening compared to the TAP with doxycycline and amoxicillin groups (P <.05).

CONCLUSIONS

The whitening treatment effect of 35% hydrogen peroxide on teeth discoloured by antibiotic pastes seems to have significantly outperformed the sodium perborate treatment. Both bleaching agents were allowed to bleach the teeth gradually each day and the effects on the 8th and 12th days were superior to the one on the 4th day.

CLINICAL RELEVANCE

The use of 35% hydrogen peroxide could be advantageous to bleach the teeth discoloured with antibiotic pastes compared to sodium perborate.

Histologic evaluation of apical pulp of immature apex following extraction, surface treatment, and replantation in different storage media in dogs

AIM

This study was designed to evaluate the apical pulp of open apex teeth following extraction, surface treatment, and preservation in different storage media in dogs.

MATERIALS AND METHODS

Four healthy male dogs were included in this prospective animal study. In the first phase of extraction, 30 teeth were extracted atraumatically from dogs (incisors and premolars) and then randomly divided into three groups based on different types of storage media: (i) milk, (ii) HBSS, and (iii) dry storage. In milk and HBSS groups, teeth were contaminated by dog's saliva and then kept in milk and HBSS solution, respectively, for 2 h. In the third group, teeth were stored in a dry storage for 2 h. Before replantation, all teeth were soaked in 10% doxycycline. After 2 months, in the second phase of extraction, all experimental teeth were extracted (40 teeth including control group). Three longitudinal sections (3-4 mm thickness) were stained with H&E and investigated under optical microscope. Histologic evaluations were performed, and data were analyzed using Kruskal-Wallis and Fisher's exact test (α = 0.05).

RESULTS

There was a significant difference between the milk and control groups regarding the presence of the odontoblastic layer and resorption (P = 0.04). Also, there was a significant difference between dry storage and control group in the presence of the odontoblastic layer (P = 0.02). There was no statistically significant difference in other histologic factors between different groups (P > 0.05). It was revealed that there is no significant difference between different groups regarding the intensity (P = 0.06) and the type of the inflammation (P = 0.24). Also, the hyperemia showed no significant difference between different groups (P = 0.51).

CONCLUSION

It was concluded that HBSS and milk are appropriate storage media. Also, it was shown that 2 h dry storage probably does not threaten the vitality of the pulp cells.

Pulp revascularization of immature permanent teeth: a review of the literature and a proposal of a new clinical protocol

Tissue engineering is a growing field. In the near future, it will probably be possible to generate a complete vital tooth from a single stem cell. Pulp revascularization is dependent on the ability of residual pulp and apical and periodontal stem cells to differentiate. These cells have the ability to generate a highly vascularized and a conjunctive rich living tissue. This one is able to colonize the available pulp space. Revascularization is a new treatment method for immature necrotic permanent teeth. Up to now, apexification procedures were applied for these teeth, using calcium dihydroxide or MTA to produce an artificial apical barrier. However, the pulp revascularization allows the stimulation of the apical development and the root maturation of immature teeth. Two pulp revascularization techniques are used in the literature, one using calcium dihydroxide and the second using a triple antibiotic paste. Based on these two different pulp revascularization protocols, which obtain the desired therapeutic success, the literature will be reviewed and analyzed according to the relevance of their choice of materials. Based on the literature, we propose a new relevant protocol and a new mixture of antibiotics.

Outcomes of revascularization treatment in immature dog's teeth

AIM

The purpose of the current study was to examine the success rate of a revascularization treatment protocol involving canal space disinfection using copious irrigation, a triantibiotic dressing, and induction of a blood clot matrix in immature dog's teeth.

MATERIALS AND METHODS

Thirty-six immature mongrel dog's teeth were divided into two experimental and two control groups. The experimental groups included a necrotic-infected group (n = 20) and a vital group (n = 10). In the group with the necrotic-infected teeth, periapical lesions were induced, and disinfection of the canals was carried out using copious irrigation and a triple antibiotic medication (metronidazole, ciprofloxacin, and tetracycline). Subsequently, the periapical tissues were irritated to initiate bleeding, producing a blood clot. A double seal of the coronal access was then placed. In the vital group, the pulp was aseptically removed before the canal was irrigated and periapical tissues irritated to induce bleeding. The same protocol as that used for the necrotic-infected group was used to seal the coronal access. In the positive control group (n = 3), after pulp removal, sterile sponges soaked in plaque suspension were placed in the pulp chambers of the teeth, after which the chambers were sealed. In the negative control group (n = 3), one untouched 1st premolar tooth in each dog was assigned and left to develop naturally. Radiographic and histological findings were evaluated at 3 and 6 months. Data analysis was performed using Fisher's exact test.

RESULTS

The necrotic-infected group radiographically demonstrated apical healing and apical closure in 70% of the cases and thickening of the walls in 40% after 6 months. The vital group showed apical closure in 77% and thickened walls in 44% of the cases after 3 months. Histological findings confirmed the radiographic findings. No significant difference was observed between the two groups (P > 0.05).

CONCLUSIONS

If necrotic-infected canals are effectively disinfected and treated according to the protocol, the ensuing revascularization response is similar to that of vital immature teeth.

Considerations for regeneration procedures

When pulp tissue becomes necrotic in immature teeth, the prognosis of the teeth is compromised. Disinfection of the root(s) presents several challenges including difficulties in cleaning and shaping large canals with open apices, obturation of canals with open apices, and potential root fractures caused by thin and/or weakened root walls. Regenerative endodontic procedures may increase the prognosis of the compromised immature tooth by re-establishment of a functional pulp tissue that fosters continued root development and immune competency. This article reviews the literature related to and discuss considerations for regenerative endodontic procedures and how these procedures may increase the prognosis for immature teeth with necrotic pulp tissue.

Management of chronic luxated central incisor with hopeless prognosis

Traumatic injuries are the most studied yet most challenging for a dentist. Extrusive luxation injuries are usually managed by repositioning tooth in the original position and pulp sensibility is evaluated at regular periodic intervals. However, when injuries are chronic, tooth is necrotic with compromised periodontal support, treatment is a challenge. Intentional replantation utilizing growth factors in fibrin rich network of platelet rich fibrin can be a treatment modality in such patients where other restorative modalities to establish function-esthetics rehabilitation is not possible.

Treatment options: biological basis of regenerative endodontic procedures

Dental trauma occurs frequently in children and often can lead to pulpal necrosis. The occurrence of pulpal necrosis in the permanent but immature tooth represents a challenging clinical situation because the thin and often short roots increase the risk of subsequent fracture. Current approaches for treating the traumatized immature tooth with pulpal necrosis do not reliably achieve the desired clinical outcomes, consisting of healing of apical periodontitis, promotion of continued root development, and restoration of the functional competence of pulpal tissue. An optimal approach for treating the immature permanent tooth with a necrotic pulp would be to regenerate functional pulpal tissue. This review summarizes the current literature supporting a biological rationale for considering regenerative endodontic treatment procedures in treating the immature permanent tooth with pulp necrosis.

Platelet Rich Fibrin in the revitalization of tooth with necrotic pulp and open apex

Regeneration of pulp-dentin complex in an infected necrotic tooth with an open apex is possible if the canal is effectively disinfected. The purpose of this case report is to add a regenerative endodontic case to the existing literature about using Platelet Rich Fibrin (PRF). A nine year old boy who accidently broke his immature maxillary central incisor tooth, developed pulpal necrosis with apical periodontitis. After the access cavity preparation, the canal was effectively irrigated with 20 ml of 5.25% sodium hypochlorite solution and 10ml of 0.2% chlorhexidine solution and dried with paper points. Triple antibiotic paste was placed inside the canal and left for 21 days. 12 ml of whole blood was drawn from the patient's right antecubital vein and centrifuged for 10 minutes to obtain the Choukroun's PRF. After the removal of the triple antibiotic paste, the PRF was placed into the canal till the level of cementoenamel junction and 3mm of grey MTA was placed directly over the PRF clot. The setting of MTA was confirmed 3 days later and the tooth was double sealed with GIC and Composite restoration. After 1 year the clinical examination revealed negative responses to percussion and palpation tests. The tooth responded positively to cold and electric pulp tests. Radiographic examination revealed continued thickening of the dentinal walls, root lengthening, regression of the periapical lesion and apical closure. On the basis of the results obtained in our case report we conclude that revitalization of necrotic infected immature tooth is possible under conditions of total canal disinfection and PRF is an ideal biomaterial for pulp-dentin complex regeneration.

Triple antibiotic paste in root canal therapy

The success of the endodontic treatment depends on the microbial suppression in the root canal and periapical region. Endodontic instrumentation alone cannot achieve a sterile condition. With the advent of non-instrumentation endodontic treatment and lesion sterilization and tissue repair, local application of antibiotics has been investigated. Triple antibiotic paste (TAP) containing metronidazole, ciprofloxacin, and minocycline has been reported to be a successful regimen in controlling the root canal pathogen and in managing non-vital young permanent tooth. This paper reviews the existing literature on biocompatibility, efficiency, drawbacks of TAP in endodontic therapy and pulp revascularization.

Regeneration potential of pulp-dentin complex: Systematic review

Aim:

The aim is to review and discuss the strategies available for the regeneration of tooth tissues based on principles of tissue engineering.

Background:

Tissue engineering is a multidisciplinary approach that aims to regenerate functional tooth-tissue structure based on the interplay of three basic key elements: Stem cells, morphogens and scaffolds. A number of recent clinical case reports have revealed the possibilities that many teeth that traditionally would be treated byapexification may be treated by apexogenesis.

Materials and Methods:

Electronic and hand search of scientific papers were carried out on the Entrez Pubmed, and the Cochrane Central Register of Controlled Trials databases using specific keywords. Specific inclusion and exclusion criteria were predetermined. The search yielded 1619 papers; out of which 65 were identified as conforming to the predetermined inclusion criteria and the remaining 1554 were excluded. Out of 65 papers, 34 papers were excluded again as different key words led to the same publications. Only 31 papers were selected, out of which 27 full-text papers were found and 4 papers were included based on only the abstracts. These 31 papers formed the basis of this review. The data were extracted from the selected studies. The data were synthesized by pooling the extracted data.

Conclusion:

The field of tissue engineering has recently shown promising results and is a good prospect in dentistry for the development of the ideal restorations to replace the lost tooth structure.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth.

Strategies for periodontal ligament cell viability: An overview

The long-term success of the reimplanted teeth is related to the maintenance of periodontal ligament (PDL) cell viability. Dental tissues are unique in comparison to most other tissues in the body due to their marked capacity for regeneration. Understanding the circumstances leading to repair and regeneration in oral tissues has been a formidable challenge. Numerous storage media have been introduced by many authors that help to maintain the PDL cell viability. To present an overview of the various available storage media. A literature search for the past 20 years was performed across the Internet database (Pubmed) and relevant citations using the keywords PDL cell viability, tooth avulsion, storage media, and the combination of all to retrieve around (n=225) citations. Articles that included follow-up of intervention for avulsed and re-implanted teeth were considered (n=44) and some literature review from well-known text books were considered. Literature supports that moist storage appears to be a more productive approach to optimize PDL cell survival. However, no medium is ideal and in vivo studies are inadequate.

Critical considerations when planning experimental in vivo studies in dental traumatology

In vivo studies are sometimes needed to understand healing processes after trauma. For several reasons, not the least ethical, such studies have to be carefully planned and important considerations have to be taken into account about suitability of the experimental model, sample size and optimizing the accuracy of the analysis. Several manuscripts of in vivo studies are submitted for publication to Dental Traumatology and rejected because of inadequate design, methodology or insufficient documentation of the results. The authors have substantial experience in experimental in vivo studies of tissue healing in dental traumatology and share their knowledge regarding critical considerations when planning experimental in vivo studies.

Traumatic displacement of maxillary permanent incisor into the nasal cavity

PURPOSE

The purpose of this paper was to describe a case of unviable alveolar repositioning of an intruded tooth into the nasal cavity and to bring the subject of intrusive tooth injury among patients with dentoalveolar fractures to the attention of trauma surgeons.

PATIENT

A 26-year-old male was involved in a car accident and crashed his mouth against the dashboard due to sudden deceleration. Intraoral examination revealed an anterior maxillary dentoalveolar fracture and absence of the central maxillary incisors, right lateral maxillary incisor, and left maxillary canine. Computed tomography showed a dislocated tooth in the nasal cavity. The "missing" left maxillary canine was easily recovered from the floor of the left nostril.

CONCLUSIONS

Because complete dislocation of a tooth can cause a frontal sinus abscess, an airway complication, a respiratory tract obstruction, and a complicated lung abscess or sinusitis, anytime a tooth is not accounted for after a dentoalveolar trauma, the possibility that it has been fully intruded should be considered. Computed tomographic scan should be a routine diagnostic study in all cases with associated missing anatomical structures in the oral and maxillofacial region. The need to involve the dental professional in the initial assessment of dental trauma in emergency rooms in hospitals is important in order to identify how many teeth might be missing after dental trauma and to correctly reposition the avulsed teeth when possible.

Treatment of the immature tooth with a non-vital pulp and apical periodontitis

Traditional methods of treatment of immature root with necrotic pulp and apical periodontitis pose multiple challenges. These challenges include disinfection of the root canal with standard protocols that aggressively use endodontic files, filling the root canal with an open apex that provides no barrier for stopping the root filling material before impinging on the periodontal tissues, and the susceptibility of the teeth to fracture because of their thin roots. Disinfection using sodium hypochlorite, apical barrier formation using calcium hydroxide as well as mineral trioxide aggregate, and pulp revascularization of fractured tooth with the help of blood clot and collagen-enhanced matrix has been discussed in detail in this article.