Treatment outcomes of regenerative endodontic therapy in immature permanent teeth with pulpal necrosis: A systematic review and network meta-analysis

AIM

The aim of this study was to assess which treatment modality regarding scaffold selection for immature permanent teeth with pulpal necrosis will be the most successful for regenerative endodontic treatment (RET).

METHODOLOGY

PubMed, Cochrane, Web of Science and Embase, and additional records until August 2022 were searched providing a total of 3021 articles, and nine of these articles were included for quantitative synthesis. The reviewers selected eligible randomized controlled trials and extracted pertinent data. Network meta-analysis was conducted to estimate treatment effects for primary outcomes (clinical and radiographic healing) and secondary outcomes (apical closure, root length and root wall thickness increase) following RET [mean difference (MD); 95% credible interval (CrI) and surface under the cumulative ranking curve (SUCRA)]. The quality of the included studies was appraised by the revised Cochrane risk of bias tool, and the quality of evidence was assessed using the GRADE approach.

RESULTS

Six interventions from nine included studies were identified: blood clot scaffold (BC), blood clot scaffold with basic fibroblast growth factor, blood clot scaffold with collagen, platelet pellet, platelet-rich plasma (PRP) and platelet-rich fibrin (PRF). The PRP scaffold showed the greatest increase in root lengthening at 6-12 months (MD = 4.2; 95% CrI, 1.2 to 6.8; SUCRA = 89.0%, very low confidence). PRP or PRF achieved the highest level of success for primary and secondary outcomes at 1-6 and 6-12 months. Blood clot scaffold (with collagen or combined with basic fibroblast growth factor (bFGF)) achieved the highest level of success for secondary outcomes beyond 12 months follow-up. A very low to low quality of evidence suggests that both PRP and PRF exhibit the greatest success evaluating primary and secondary outcomes within 12 months postoperatively compared to the traditional blood clot scaffold protocol.

CONCLUSION

Limited evidence suggests both PRP and PRF exhibit success in the short-term, not long-term. The value of this information stems in its recommendation for future randomized trials prioritizing both of these materials in their protocol.

Evaluation of the effectiveness of different treatment approaches in preventing coronal discoloration caused by regenerative endodontic treatment

OBJECTIVES

This study aimed to evaluate the effectiveness of Teethmate desensitizer, a dentin bonding agent (DBA), Nd:YAG laser, and Er:YAG laser, which provides dentin tubule occlusion in the pulp chamber with different mechanisms, in preventing tooth discoloration due to regenerative endodontic treatment.

MATERIALS AND METHODS

One hundred five extracted maxillary human incisors with single roots and single canals were included in the study. The apical third of each tooth was resected below the enamel-cementum junction (CEJ) to obtain a standard root length as 10 ± 1 mm. Root canal preparation was performed using the ProTaper Next files up to X5. Root canals were prepared with Gates Glidden (# 2-4) burs to simulate the immature root apex and an apical diameter of 1.1 ± 0.1 mm was obtained. The teeth were randomly divided into 7 groups (n = 15): DBA, Teethmate, Nd:YAG, Er:YAG, Biodentine, Blood, and Negative Control. Relevant dentin tubule occlusion methods were applied to DBA, Teethmate, Nd:YAG, and Er:YAG groups. Following dentin tubule occlusion procedures, Biodentine was placed on the blood clot after filling the root canals with blood up to 4 mm below the CEJ. No dentin tubule occlusion procedure was applied for Blood and Biodentine groups. Color measurement was performed with the spectrophotometer Vita Easyshade Advance before treatment, immediately after treatment, and at days 7, 30, and 90. Data were converted to L*a*b color values of Commission International de I'Eclairage (CIE L*a*b) and ΔE values were calculated. Two-way ANOVA and post hoc Tukey test (p = 0.05) were performed for statistical analysis.

RESULTS

A clinically detectable color change was observed in all groups except for the negative control (ΔE ≥ 3,3). It was observed that Biodentine used alone has a potential for discoloration. It was determined that as the contact time with blood increased, tooth discoloration increased. However, no significant difference was found between dentin tubule occlusion methods in preventing color change (p > 0.05).

CONCLUSIONS

It was determined that no dentin tubule occlusion method could 100% prevent discoloration caused by RET.

CLINICAL RELEVANCE

DBA and Teethmate, which do not have a significant difference in terms of preventing color change, are considered to be suitable for dentin tubule occlusion due to their ease of application and low cost compared to Nd:YAG laser and Er:YAG laser.

Determination of crown discoloration and fluorescence induced by different medications used in regenerative endodontic procedures: An ex vivo study

Background

Crown discoloration is an undesirable side effect of the use of triple antibiotic paste (TAP) in regenerative endodontic procedures (REPs). The aim of this ex vivo study was to assess the potential for tooth discoloration and induction of fluorescence associated with the use of TAP containing either doxycycline (DOX) or clindamycin (CLIN), and of calcium hydroxide (Ca(OH)2), by spectrophotometric analysis and confocal laser scanning microscopy (CLSM).

Material and Methods

A total of forty single-rooted human teeth extracted by therapeutic indication were used. The root canals were enlarged using the step-back technique up to a K #80 file and were randomly divided into four experimental groups (10 specimens each): i)Ca(OH)2 group, ii)TAP with DOX group, iii) TAP with CLIN group, iv) Control group (no treatment). To quantify the change of color of the different groups of teeth included, the Vita Easyshade advance 4.0 spectrophotometer was used. CLSM was used to determine fluorescence.

Results

After 28 days of action inside the root canal, no extreme discoloration was visible, to the naked eye, in any of the teeth included in the study. Under the conditions of this ex vivo study, TAP with DOX induced the highest crown discoloration among the medicaments tested. In contrast, Ca(OH)2 and TAP with CLIN did not induce crown discoloration after 28 days. The TAP with DOX group presented the highest fluorescence measurements.

Conclusions

Considering the discoloration potential and fluorescence changes in TAP with DOX or other tetracyclines, and the cytotoxic effect of TAPs, we recommend the use of Ca(OH)2 for REPs.

Key words:Discoloration, doxycycline, clinadamycin, calcium hydroxide, endodontics.

Regenerative Endodontic Procedure of Immature Permanent Teeth with Leukocyte and Platelet-rich Fibrin: A Multicenter Controlled Clinical Trial

INTRODUCTION

The aim of this nonrandomized, multicenter controlled clinical trial was to evaluate the impact of leukocyte-platelet-rich fibrin (LPRF) on regenerative endodontic procedures (REPs) of immature permanent teeth in terms of periapical bone healing (PBH) and further root development (RD).

METHODS

Healthy patients between 6-25 years with an inflamed or necrotic immature permanent tooth were included and divided between the test (= REP + LPRF) and control (= REP-LPRF) group depending on their compliance and the clinical setting (university hospital or private practice). After receiving REP ± LPRF, the patients were recalled after 3, 6, 12, 24, and 36 months. At each recall session, the teeth were clinically and radiographically (by means of a periapical radiograph [PR]) evaluated. A cone-beam computed tomographic (CBCT) imaging was taken preoperatively and 2 and 3 years postoperatively. PBH and RD were quantitatively and qualitatively assessed.

RESULTS

Twenty-nine teeth with a necrotic pulp were included, from which 23 (9 test and 14 control) were analyzed. Three teeth in the test group had a flare-up reaction in the first year after REP. Except for 2 no shows, all the analyzed teeth survived up to 3 years after REP, and, in case of failure, apexification preserved them. Complete PBH was obtained in 91.3% and 87% of the cases based on PR qualitative and quantitative evaluation, respectively, with no significant difference between the groups with respect to the baseline. The PR quantitative change in RD at the last recall session with respect to the baseline was not significant (all P values > .05) in both groups. The qualitative assessment of the type of REP root healing was nonuniform. In the test group, 55.6% of the teeth presented no RD and no apical closure. Only 50% of the 14 teeth assessed with CBCT imaging presented complete PBH. Regarding volumetric measurements on RD 3 years after REP for the change with respect to the baseline in root hard tissue volume, mean root hard tissue thickness, and apical area, the control group performed significantly in favor of RD than the test group (P = .03, .003, and 0.05 respectively). For the volumetric change 3 years after REP with respect to the baseline in root length and maximum root hard tissue thickness, no significant difference (P = .72 and .4, respectively) was found between the groups. The correlation between the PR and CBCT variables assessing RD was weak (root lengthening) to very weak (root thickening).

CONCLUSIONS

REP-LPRF seems to be a viable treatment option to obtain PBH and aid further RD of necrotic immature permanent teeth. Caution is needed when evaluating REP with PR.

Regenerative Endodontic Treatment of Bilateral Necrotic Immature Permanent Maxillary Central Incisors with Platelet-rich Plasma versus Blood Clot: A Split Mouth Double-blinded Randomized Controlled Trial

AIM

Clinical and radiographic assessment of the regenerative potential of bilateral immature permanent maxillary central incisors with necrotic pulps using blood clot (BC) and platelet-rich plasma (PRP) scaffolds.

TRIAL DESIGN

This is a split mouth double-blinded parallel randomized controlled clinical trial.

SUBJECTS AND METHODS

Randomization and blinding: the study started with 15 patients with bilateral maxillary immature permanent central incisors with necrotic pulp. The two upper bilateral central incisors were randomly assigned to either the control (BC scaffold) group I or examined (PRP scaffold) group II. Participant: 13 patients aged 8-14 years fulfilled the study requirements. A follow-up was done for 3, 6, 9, and 12 months. Standardized radiographs were collected during the follow-up period, and radiographic changes were measured using Image J software. Primary outcome measured were clinical: pain, mobility, swelling, and sinus/fistula. Radiographic outcome included increased root length and increase in root thickness. Secondary outcomes were clinical: discoloration and sensibility test. Radiographic outcome included an increase in bone density measurements and a decrease in apical diameter. Standardized radiographs were collected during the follow-up period, and radiographic changes were measured using Image J software.

RESULTS

All 26 treated teeth survived during the 12-month follow-up period with 100% success rate. PRP-treated teeth showed a statistically significant increase in radiographic root length, width, periapical bone density, and a decrease in apical diameter when compared with BC. At the end of 12 months, all treated teeth did not respond to the sensibility test. BC displayed a significantly higher amount of crown discoloration compared to the PRP group.

CONCLUSION

For necrotic immature teeth, regenerative endodontic treatment using PRP is a desirable alternative to BC and shows excellent 12-months prognosis.

HOW TO CITE THIS ARTICLE

Rizk HM, AL-Deen MSS, et al. Regenerative Endodontic Treatment of Bilateral Necrotic Immature Permanent Maxillary Central Incisors with Platelet-rich Plasma versus Blood Clot: A Split Mouth Double-blinded Randomized Controlled Trial. Int J Clin Pediatr Dent 2019;12(4):332-339.

Bone, Periodontal and Dental Pulp Regeneration in Dentistry: A Systematic Scoping Review

Abstract The aim of presented systematic scoping review was to investigate the actual and future clinical possibilities of regenerative therapies and their ability to regenerate bone, periodontal and pulp with histological confirmation of the nature of formed tissue. Electronic search was conducted using a combination between Keywords and MeSH terms in PubMed, Scopus, ISI-Web of Science and Cochrane library databases up to January 2016. Two reviewers conducted independently the papers judgment. Screened studies were read following the predetermined inclusion criteria. The included studies were evaluated in accordance with Arksey and O’Malley’s modified framework. From 1349 papers, 168 completed inclusion criteria. Several characterized and uncharacterized cells used in Cell Therapy have provided bone regeneration, demonstrating bone gain in quantity and quality, even as accelerators for bone and periodontal regeneration. Synthetic and natural scaffolds presented good cell maintenance, however polyglycolid-polylactid presented faster resorption and consequently poor bone gain. The Growth Factor-Mediated Therapy was able to regenerate bone and all features of a periodontal tissue in bone defects. Teeth submitted to Revascularization presented an increase of length and width of root canal. However, formed tissues not seem able to deposit dentin, characterizing a repaired tissue. Both PRP and PRF presented benefits when applied in regenerative therapies as natural scaffolds. Therefore, most studies that applied regenerative therapies have provided promising results being possible to regenerate bone and periodontal tissue with histological confirmation. However, pulp regeneration was not reported. These results should be interpreted with caution due to the short follow-up periods.

Comparative evaluation of angiogenesis using a novel platelet-rich product: An in vitro study

Background:

In vivo angiogenesis is normal and vital process in growth and development, wound healing, and formation of granulation tissue wherein new blood vessels form from preexisting vessels as part of revascularization. Platelet-rich products promote wound healing associated with angiogenesis. Biomaterials such as titanium were found to be angiogenic. Unlike in vivo situations, in vitro angiogenesis, study cells, within a controlled environment.

Aims:

The aim of this study is to evaluate the angiogenic potential of a novel platelet-rich product.

Materials and Methods:

Blood was drawn from volunteers with informed consent. Blood samples were centrifuged to obtain platelet-rich products. Platelet concentrates prepared were platelet-rich plasma (PRP), platelet-rich fibrin, and a novel platelet-rich product which is titanium-prepared PRP (TPRP), obtained using titanium. The study which compared platelet concentrate was divided into four groups subjected to tissue culture. Phase-contrast microscope was used to determine the rate of growth by cell counting.

Statistical Analysis:

ANOVA was used for comparison within groups and post hoc for multiple comparisons.

Results:

TPRP group showed granular ground substance. Group with platelet-rich fibrin (PRF) shows a high rate of growth whereas those with TPRP showed better growth rate when compared to its counterpart, PRP.

Conclusions:

This is the first study which introduces TPRP. Previous studies have proved that titanium-prepared PRF has better structural quality than its counterpart platelet-rich fibrin. This study concludes that TPRP has better angiogenic potential than its counterpart PRP. Further in vivo studies are needed to promote TPRP as a new generation of platelet products.

Efficacy of Autologous Platelet Concentrates in Regenerative Endodontic Treatment: A Systematic Review of Human Studies

INTRODUCTION

The latest research concerns the use of platelet concentrates, which are introduced into the root canal. The aim of this study was to examine the effectiveness of platelet-rich fibrin and platelet-rich plasma in regenerative endodontics.

METHODS

This literature review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The literature search included all publications without a year limit. The last search was performed on January 31, 2018. An electronic search was performed using MEDLINE (PubMed), Cochrane, and Scopus. Articles were selected that addressed the following research question: Is the use of platelet concentrates effective in regenerative endodontics? The necessary information was extracted by 2 authors independently using a standardized form.

RESULTS

The search resulted in 426 titles from all databases, and 26 studies met the inclusion criteria. Five were randomized trials, and the others were case reports. All described cases were asymptomatic. Only 3 cases from randomized trials were unsuccessful. Ten of the case reports found positive results for pulp vitality. In randomized trials, the teeth treated with platelet concentrates showed better results for pulp vitality. In almost all cases, they also described thickening and lengthening of the root wall and closure of the apical foramen, which are important for successful treatment of permanent teeth.

CONCLUSIONS

This review showed that procedures using autologous platelet concentrates were successful in treating permanent teeth with root development. However, more long-term clinical studies are needed.

Alternative to Avoid Tooth Discoloration after Regenerative Endodontic Procedure: A Systematic Review

Abstract This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

Evaluation of the preventive efficacy of three dentin tubule occlusion methods against discoloration caused by triple-antibiotic paste

The aim of this in vitro study was to evaluate the preventive efficacy of three dentin tubule occlusion methods against discoloration caused by triple-antibiotic paste (TAP). Sixty extracted human incisors were sectioned, and the access was opened. The specimens were randomly allocated to the following four groups (n = 15): bonding application (BD), teethmate desensitizer (TM), Nd:YAG laser application (LS), and no surface treatment (control, C). Specimens were discolored with TAP over a period of 3 weeks. The color was measured by spectrophotometry at two time-points: initially and after 3 weeks of TAP placement. Color differences (∆E) were calculated and analyzed. Discoloration was visually noticed in all teeth after 3 weeks. The differences between the control group and the three dentin tubule occlusion methods were statistically significant (p < 0.05); however, there were no statistically significant differences among the BD, TM, and LS groups (p > 0.05).

Spectrophotometric analysis of discoloration and internal bleaching after use of different antibiotic pastes

OBJECTIVES

To investigate teeth's antibiotic-induced color differences after bleaching using two different techniques.

MATERIALS AND METHODS

One hundred twenty extracted maxillar human incisors were examined. The specimens were randomly divided into six groups, each receiving one of six antibiotic paste fillings: (1) triple antibiotic paste (TAP) with minocycline, (2) double antibiotic paste (DAP), (3) TAP with amoxicillin, (4) TAP with cefaclor, (5) TAP with doxycycline, and (6) no filling (control group). Spectrophotometric measurements were obtained at baseline and then during the first, second, and third weeks after paste placement. The specimens discolored by antibiotics pastes were randomly divided into two subgroups: (1) internal bleaching with hydrogen peroxide (H₂O₂₎ and (2) internal bleaching with H₂O₂ plus Nd-YAG laser irradiation. The ∆E value was calculated and analyzed using a two-way analysis of variance and post-hoc Tukey's test (α = 0.05).

RESULTS

The ∆E for all groups showed color differences exceeding the perceptibility threshold (∆E ˃ 3.7) at all time points except in the control and DAP groups. Minocycline-induced TAP showed the most severe coronal discoloration (32.42). When the ∆E was examined, thermo/photo bleaching (22.01 ± 8.23) caused more bleaching than walking bleaching (19.73 ± 5.73) at every time point (P = 0.19). No group returned to the original color after bleaching (P < 0.05).

CONCLUSIONS

Except for DAP, all antibiotic pastes caused discoloration. Internal bleaching with Nd-YAG laser can be useful for bleaching/removing this discoloration.

CLINICAL RELEVANCE

For clinically successful final appearances, understanding the effects of bleaching procedures on antibiotic paste discoloration is important.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

Histological assessment of regenerative endodontic treatment in animal studies with different scaffolds: A systematic review

BACKGROUND/AIM

The concept of regenerative endodontic procedures remains controversial. The aim of this study was to evaluate the histology of the tissues formed in immature animal teeth with necrotic and infected pulps after attempted endodontic regeneration procedures using different scaffolds.

DESIGN

A systematic electronic literature search was performed in PubMed, Web of Science, Scopus, EMBASE, DOSS, and Cochrane Library databases. The terms used were a combination of the following: "immature permanent necrotic tooth or teeth" or "open apex or apices" and "regeneration or revitalization or revascularization" and "histology." The inclusion criteria comprised animal studies with histological examination following regenerative endodontics in immature necrotic-infected permanent teeth.

RESULTS

From 123 screened studies, 13 met the inclusion criteria. Formation of dentin-like tissue on the dentinal walls was reported in only 4% of teeth treated with blood clot scaffold and 2% treated with blood clot with additional materials. Cementum-like hard tissue was found in 64% of teeth with blood clot, 80% treated with blood clot with additional materials, 50% treated with alternative scaffolds, and 5% that were left empty. Bone-like tissue was reported in 10% of teeth treated with blood clot, 2% treated with blood clot with additional materials, and 4% treated with alternative scaffolds. The tissues in the canal space were found to be connective tissue with infiltration of fibroblast-like cells and blood vessels. Forty-six percent of the studies reported formation of periodontal ligament-like tissues.

CONCLUSIONS

None of the regeneration protocols resulted in the predictable formation of a true pulp-dentin complex.

Use of platelet-rich plasma for regeneration in non-vital immature permanent teeth: Clinical and cone-beam computed tomography evaluation

Objective

This study was performed to assess the clinical and radiological outcomes of a revascularization procedure in immature teeth with apical periodontitis using platelet-rich plasma (PRP). The PRP protocol and conventional revascularization protocol, which used a blood clot as the scaffold, were compared.

Methods

Thirty non-vital immature permanent teeth were randomly categorized into two groups. After disinfecting the root canal space with triple antibiotic paste (1:1:1 ciprofloxacin, metronidazole, and cefaclor), a tissue scaffold was created using either PRP or a blood clot (control) and covered with white mineral trioxide aggregate. All cases were followed up clinically and radiographically for 12 months. Differences in bone density, root length, and lesion size were calculated using preoperative and postoperative computed tomography images. The means of the differences in individual parameters in the blood clot and PRP groups were compared using the Mann–Whitney U test.

Results

After 5 months, sensitivity tests (cold and electric pulp tests) elicited a delayed positive response in 23 sites. At 12 months, cone-beam computed tomography revealed resolution or a decrease in lesion size and an increase in bone density in all 30 (100%) teeth. Additionally, continued root development was observed in 22 (73%) teeth and early root growth was observed in the test group (mineral trioxide aggregate with PRP).

Conclusions

The results of this study suggest that PRP can serve as a successful scaffold for regenerative endodontic treatment. With the exception of a significant increase in root length, the results of treatment with PRP were not significantly different from those of the conventional protocol using a blood clot as the scaffold.

Retreatment of failed regenerative endodontic of orthodontically treated immature permanent maxillary central incisor: a case report

A revascularization procedure was shown to be the best alternative therapy for immature teeth with necrotic pulp and apical infection. A 12 year old female with a history of trauma to her upper central incisor and a sinus tract was referred for endodontic treatment. She was an active orthodontic patient and had undergone regenerative endodontic treatment for the past 2 years. Clinical examination revealed no response to sensibility, percussion, and palpation tests. The preoperative radiograph showed an open apex and apical rarefaction. The case was diagnosed as previously treated tooth with asymptomatic apical periodontitis. Regenerative endodontic retreatment was performed, and the case was followed for 3 years. Clinical, radiographic, and cone-beam computed tomography follow-up examination revealed an asymptomatic tooth, with evidence of periapical healing and root maturation.

The impact of autologous platelet concentrates on endodontic healing: a systematic review

The current literature was reviewed to determine the impact of autologous platelet concentrates (APCs) on endodontic healing. All types of clinical study designs concerning any kind of endodontic treatment involving the application of APCs were included. Two independent reviewers searched three databases (PubMed, Embase, and Cochrane Library) for studies, complemented by hand search, until 16/1/2016. From the 423 identified records, 48 articles met the inclusion criteria. Selected randomized controlled clinical trials (RCTs) underwent Cochrane Collaboration's risk-of-bias assessment and data extraction. Only two RCTs showed low risk of bias. There was considerable heterogeneity between the RCTs with regard to the type of therapy, type of APCs, assessment method, and study quality, and therefore the data could not be analyzed quantitatively. The included case reports/series and non-randomized comparative studies underwent qualitative analysis with the revised Methodological Index for Non-Randomized Studies (MINORS) and data extraction. The two comparative non-randomized studies scored qualitatively high, though the MINORS-scores of the case series and reports were dispersed. APCs were involved in five endodontic treatment modalities, namely apexification, regenerative endodontic procedures, pulpotomy, apical surgery, and treatment of endo-perio/perio-endo lesions. APCs seem to accelerate postoperative bone healing, augment the patients' postoperative quality of life, aid further root development, and support maintenance/regaining of pulp vitality. No adverse events were reported. APCs in endodontic treatments seem to contribute to the healing of soft and hard tissues, though there is a lack of long-term high quality clinical trials and standardized treatment protocols.

Effectiveness of conventional syringe irrigation, vibringe, and passive ultrasonic irrigation performed with different irrigation regimes in removing triple antibiotic paste from simulated root canal irregularities

Background:

This study evaluated the efficacy of a sonic device (Vibringe), passive ultrasonic irrigation (PUI), and conventional syringe irrigation (CSI) in the removal of triple antibiotic paste (TAP) from artificial standardized grooves in the apical and coronal thirds of a root canal.

Materials and Methods:

One-hundred eighteen root canals were prepared using the ProTaper system. The roots were split longitudinally, and a standardized groove was prepared in the apical and coronal parts of one segment. The grooves were filled with TAP, and the roots were reassembled. The roots were randomly divided into nine experimental groups and two control groups, according to the following irrigation methods: (1) CSI with sodium hypochlorite (NaOCl) + ethylenediaminetetraacetic acid (EDTA), (2) CSI/EDTA, (3) CSI/NaOCl, (4) PUI/NaOCl + EDTA, (5) PUI/EDTA, (6) PUI/NaOCl, (7) Vibringe/NaOCl + EDTA, (8) Vibringe/EDTA, and (9) Vibringe/NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope.

Results:

In the apical third, Vibringe/NaOCl + EDTA and PUI/NaOCl + EDTA were superior to the other groups (P < 0.05); there was no significant difference between the other experimental groups (P > 0.05). In the coronal third, there was no significant difference between the experimental groups (P > 0.05).

Conclusions:

The use of the NaOCl/EDTA combination together with sonic or ultrasonic agitation improved the removal of TAP from the apical third.

Recent advancements in regenerative dentistry: A review

Although human mouth benefits from remarkable mechanical properties, it is very susceptible to traumatic damages, exposure to microbial attacks, and congenital maladies. Since the human dentition plays a crucial role in mastication, phonation and esthetics, finding promising and more efficient strategies to reestablish its functionality in the event of disruption has been important. Dating back to antiquity, conventional dentistry has been offering evacuation, restoration, and replacement of the diseased dental tissue. However, due to the limited ability and short lifespan of traditional restorative solutions, scientists have taken advantage of current advancements in medicine to create better solutions for the oral health field and have coined it "regenerative dentistry." This new field takes advantage of the recent innovations in stem cell research, cellular and molecular biology, tissue engineering, and materials science etc. In this review, the recently known resources and approaches used for regeneration of dental and oral tissues were evaluated using the databases of Scopus and Web of Science. Scientists have used a wide range of biomaterials and scaffolds (artificial and natural), genes (with viral and non-viral vectors), stem cells (isolated from deciduous teeth, dental pulp, periodontal ligament, adipose tissue, salivary glands, and dental follicle) and growth factors (used for stimulating cell differentiation) in order to apply tissue engineering approaches to dentistry. Although they have been successful in preclinical and clinical partial regeneration of dental tissues, whole-tooth engineering still seems to be far-fetched, unless certain shortcomings are addressed.

Biocompatibility of two experimental scaffolds for regenerative endodontics

OBJECTIVES

The biocompatibility of two experimental scaffolds for potential use in revascularization or pulp regeneration was evaluated.

MATERIALS AND METHODS

One resilient lyophilized collagen scaffold (COLL), releasing metronidazole and clindamycin, was compared to an experimental injectable poly(lactic-co-glycolic) acid scaffold (PLGA), releasing clindamycin. Human dental pulp stem cells (hDPSCs) were seeded at densities of 1.0 × 10(4), 2.5 × 10(4), and 5.0 × 10(4). The cells were investigated by light microscopy (cell morphology), MTT assay (cell proliferation) and a cytokine (IL-8) ELISA test (biocompatibility).

RESULTS

Under microscope, the morphology of cells coincubated for 7 days with the scaffolds appeared healthy with COLL. Cells in contact with PLGA showed signs of degeneration and apoptosis. MTT assay showed that at 5.0 × 10(4) hDPSCs, COLL demonstrated significantly higher cell proliferation rates than cells in media only (control, p < 0.01) or cells co-incubated with PLGA (p < 0.01). In ELISA test, no significant differences were observed between cells with media only and COLL at 1, 3, and 6 days. Cells incubated with PLGA expressed significantly higher IL-8 than the control at all time points (p < 0.01) and compared to COLL after 1 and 3 days (p < 0.01).

CONCLUSIONS

The COLL showed superior biocompatibility and thus may be suitable for endodontic regeneration purposes.

Regenerative endodontics--Creating new horizons

Trauma to the dental pulp, physical or microbiologic, can lead to inflammation of the pulp followed by necrosis. The current treatment modality for such cases is non-surgical root canal treatment. The damaged tissue is extirpated and the root canal system prepared. It is then obturated with an inert material such a gutta percha. In spite of advances in techniques and materials, 10%-15% of the cases may end in failure of treatment. Regenerative endodontics combines principles of endodontics, cell biology, and tissue engineering to provide an ideal treatment for inflamed and necrotic pulp. It utilizes mesenchymal stem cells, growth factors, and organ tissue culture to provide treatment. Potential treatment modalities include induction of blood clot for pulp revascularization, scaffold aided regeneration, and pulp implantation. Although in its infancy, successful treatment of damaged pulp tissue has been performed using principles of regenerative endodontics. This field is dynamic and exciting with the ability to shape the future of endodontics. This article highlights the fundamental concepts, protocol for treatment, and possible avenues for research in regenerative endodontics.

Time-dependent effectiveness of the intracanal medicaments used for pulp revascularization on the dislocation resistance of MTA

BACKGROUND

The aim of the present study was to evaluate the time-dependent effectiveness of the intracanal medicaments used in pulp revascularization on the dislocation resistance of mineral trioxide aggregate (MTA).

METHODS

One hundred ninety-two extracted human maxillary incisor teeth were sectioned apically 12 mm below and coronally 2 mm above the cemento-enamel junction. Roots were enlarged to size 40 (Protaper F4). Next, Peeso reamers from #1 to #5 were used sequentially. Sodium hypochlorite (2.5 %), EDTA (17 %), and distilled water were used in final irrigation. The specimens were randomly divided into four groups (n = 48): Group 1, in which triple antibiotic paste (TAP) (ciprofloxacin + metronidazole + minocycline) was prepared and delivered into the canals using a lentulo spiral; Group 2, in which double antibiotic paste (DAP) (ciprofloxacin + metronidazole) was placed into the canals; Group 3, in which calcium hydroxide paste (CH) (calcium hydroxide + distilled water) was introduced into the roots; and Group 4 (control), in which no medicament was applied into the root canals. Then, the samples were kept in saline solution for 2, 4, and 12 weeks, after which time 16 roots were selected randomly from each group, representing the samples of each time point. After removal of the medicaments, MTA was placed into the coronal third of the roots, and the samples were incubated for 7 days. A push-out test was used to measure the dislocation resistance (DR) of MTA. The data were analyzed using a two-way ANOVA followed by Tukey's pairwise comparisons (p = 0.05).

RESULTS

The time factor displayed a significant effect on the DR of MTA (p < 0.05). All medicaments resulted in significantly smaller DR values after 12 weeks compared to after 1 week (p < 0.05). A significant unfavorable effect of TAP and DAP was observed as early as 2 weeks after the application, while 2 and 4 weeks after the application of CH there was no effect on the DR of MTA. No significant differences were found between the time points in the control group (p > 0.05).

CONCLUSION

The type and the intracanal duration of medicaments used for pulp revascularization should be chosen carefully to provide maximum antimicrobial effect while creating a favorable environment both for stem cell attachment and MTA adhesion.

Pulp Revascularization on Permanent Teeth with Open Apices in a Middle-aged Patient

Pulp revascularization is a promising procedure for the treatment of adolescents' immature permanent teeth with necrotic pulp and/or apical periodontitis. However, the ability to successfully perform pulp revascularization in a middle-aged patient remains unclear. A 39-year-old woman was referred for treatment of teeth #20 and #29 with necrotic pulp, extensive periapical radiolucencies, and incomplete apices. Pulp revascularization procedures were attempted, including root canal debridement, triple antibiotic paste medication, and platelet-rich plasma transplantation to act as a scaffold. Periapical radiographic and cone-beam computed tomographic examinations were used to review the changes in the apical lesions and root apex configuration. The patient remained asymptomatic throughout the 30-month follow-up. Periapical radiographic examination revealed no change in the apical lesions of either tooth at 8 months. The periapical radiolucency disappeared on tooth #20 and significantly decreased on tooth #29 by the 30-month follow-up, findings that were also confirmed by cone-beam computed tomographic imaging. No evidence of root lengthening or thickening was observed. Successful revascularization was achieved in a middle-aged patient's teeth.

Comparison of bond strength of self-etch adhesive to pulp chamber dentin after placement of calcium hydroxide and various antibiotic pastes

OBJECTIVE

The aim of this study was to evaluate the effect of calcium hydroxide, double antibiotic paste (DAP) and triple antibiotic paste (TAP) with minocycline, cefaclor and amoxicillin on the micro tensile bond strength (µTBS) of self-etch adhesive to pulp chamber dentin.

MATERIALS AND METHODS

Sixty mandibular first molars were cut horizontally and randomly divided into a control group and five experimental groups, which received an intra-canal dressing, as follows: calcium hydroxide, DAP, TAP with minocycline, TAP with cefaclor and TAP with amoxicillin. After storing the specimens for 4 weeks, the medicaments were removed by irrigation with 10 mL each of the following solution: 2.5% NaOCl, 17% EDTA and distilled water. A self-etch adhesive (Clearfil S3 Bond, Okayama, Japan) was applied and composite resin (Clearfil Majesty Posterior, Kuraray Medical Inc., Japan) was placed into the cavity. A µTBS test was performed on each specimen using a universal test machine.

RESULTS

The DAP reduced the µTBS of self-etch adhesive compared to the control group, calcium hydroxide and TAP with minocycline and with cefaclor (p < 0.05). However, the other medicaments did not result in a decreased µTBS of self-etch adhesive to pulp chamber dentin as compared to the control group (p > 0.05).

CONCLUSIONS

The use of DAP resulted in a reduced µTBS of self-etch adhesive to pulp chamber dentin.

Intracanal Antibiotic Medication for Sustained Root Surface Disinfection-A Laboratory Evaluation

Purpose:

To measure the release of an antibiotic mixture of ciprofloxacin, cerfuroxim and metronidazole (TreVitaMix, TVM) through human dentine and to assess the growth inhibition of Fusobacterium nucleatum.

Material and Methods:

Twenty-four extracted human incisors were scaled and endodontically treated. Root canals were either filled with antibiotic tri-mixture (TVM) or with the carrier material alone (propylene glycol, PG) and were coronally and apically sealed with a flowable composite. Transradicular medicament release was spectrophotometrically measured at 277 nm in simulated body fluid for up to 21 days. In a second part, an agar diffusion assay (F. nucleatum) with representative TVM concentrations as determined in the first part was performed to study the growth inhibition. Samples were anaerobical incubated for 48 h and inhibition zones were measured.

Results:

TVM was spectrophotometrically detectable in the immersion solution and released in decreasing concentrations up to 21 days (222.5 ± 65.2 mg/ml at day 1 and 35.1 ± 15.6 mg/ml at day 21). In addition, inhibition zones were shown in the agar diffusion assay at representative TVM concentrations. The carrier material showed no antibacterial effect.

Conlusion:

TVM showed the potential to penetrate through dentine and to inhibit bacterial growth. Therefore, it might have the potential to disinfect the outer root surface in perio-endo lesions, but further research is needed to confirm these observations.

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.

Efficacy of platelet-rich plasma as a scaffold in regenerative endodontic treatment

INTRODUCTION

Current research is concerned with discovering better scaffolds for use in regenerative endodontic treatment. This study aimed to clinically and radiographically evaluate the efficacy of platelet-rich plasma (PRP) used as a scaffold in regenerative endodontic treatment and compare it with that of a conventional blood clot (BC) scaffold.

METHODS

A total of 20 necrotic, single-rooted immature teeth were randomly distributed into 2 groups. After disinfecting the root canal space with triple antibiotic paste (1:1:1 ciprofloxacin, metronidazole, and cefaclor), a tissue scaffold was created by using either PRP or BC and covered with white mineral trioxide aggregate. Clinical and radiographic follow-up examinations were performed once every 3 months during an 18-month period. Differences in root area were calculated from preoperative and postoperative radiographs. Fisher exact and Mann-Whitney U tests were used to evaluate differences between groups, with P value <.05 considered to be statistically significant.

RESULTS

All 20 teeth were clinically asymptomatic during 18-month follow-up period; however, 1 tooth in the BC group exhibited periapical pathosis and was judged radiographically unsuccessful. Complete apical closure was observed in a mean of 8.1 months in the PRP group compared with 9 months in the BC group. The PRP group exhibited 9.86% increase in root area, compared with 12.6% increase in the BC group. The difference in success rates between the groups was not statistically significant (P > .05).

CONCLUSIONS

PRP successfully created a scaffold for regenerative endodontic treatment; however, treatment outcomes did not differ significantly between PRP and conventional BC scaffold.

Antimicrobial activity of platelet-rich plasma and other plasma preparations against periodontal pathogens

BACKGROUND

In addition to releasing a pool of growth factors during activation, platelets have many features that indicate their role in the anti-infective host defense. The antimicrobial activities of platelet-rich plasma (PRP) and related plasma preparations against periodontal disease-associated bacteria were evaluated.

METHODS

Four distinct plasma fractions were extracted in the formulation used commonly in dentistry and were tested for their antibacterial properties against three periodontal bacteria: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. The minimum inhibitory concentration of each plasma preparation was determined, and in vitro time-kill assays were used to detect their abilities to inhibit bacterial growth. Bacterial adhesion interference and the susceptibility of bacterial adherence by these plasma preparations were also conducted.

RESULTS

All plasma preparations can inhibit bacterial growth, with PRP showing the superior activity. Bacterial growth inhibition by PRP occurred in the first 24 hours after application in the time-kill assay. PRP interfered with P. gingivalis and A. actinomycetemcomitans attachment and enhanced exfoliation of attached P. gingivalis but had no influences on F. nucleatum bacterial adherence.

CONCLUSIONS

PRP expressed antibacterial properties, which may be attributed to platelets possessing additional antimicrobial molecules. The application of PRP on periodontal surgical sites is advisable because of its regenerative potential and its antibacterial effects.

Effect of calcium hydroxide and double and triple antibiotic pastes on the bond strength of epoxy resin-based sealer to root canal dentin

INTRODUCTION

The aim of this study was to evaluate the effects of calcium hydroxide (CH) and triple (TAP) and double (DAP) antibiotic pastes on the bond strength of an epoxy resin-based sealer (AH Plus Jet; Dentsply DeTrey, Konstanz, Germany) to the root canal dentin.

METHODS

Sixty-four single-rooted human mandibular premolars were decoronated and prepared using the rotary system to size 40. The specimens were randomly divided into a control group (without intracanal dressing) and 3 experimental groups that received an intracanal dressing with either CH, DAP, or TAP (n = 16). The intracanal dressing was removed by rinsing with 10 mL 17% EDTA followed by 10 mL 2.5% sodium hypochlorite. The root canals were then obturated with gutta-percha and AH Plus Jet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using 2-way analysis of variance and Tukey post hoc tests to detect the effect of the independent variables (intracanal medicaments and root canal thirds) and their interactions on the push-out bond strength of the root canal filling material to the root dentin (P = .05).

RESULTS

The push-out bond strength values were significantly affected by the intracanal medicaments (P < .001) but not by the root canal thirds (P > .05). In the middle and apical third, the bond strength of the TAP group was higher than those of the CH and DAP groups (P < .05).

CONCLUSIONS

The DAP and CH did not affect the bond strength of the epoxy resin-based sealer. Additionally, the TAP improved the bond strength of the epoxy resin-based sealer in the middle and apical thirds.

The use of platelet rich plasma in the treatment of immature tooth with periapical lesion: a case report

This study describes the treatment of an immature permanent tooth with periapical lesion which was treated with regenerative approach using platelet rich plasma (PRP). The root canal of immature human permanent tooth with periapical lesion was gently debrided of necrotic tissue and disinfected with 2.5% NaOCl, and then medicated with triple antibiotic paste comprised of ciprofloxacin, metronidazole, and tetracycline. When the tooth was asymptomatic, PRP and mineral trioxide aggregate (MTA) were placed into the root canal. Six months after PRP treatment, radiographical examination revealed resolution of the radiolucency and progressive thickening of the root wall and apical closure. Our findings suggest that PRP can be used for the treatment of immature permanent teeth with periapical lesion, as part of a regenerative endodontic treatment procedure.

Efficacy of needle irrigation, EndoActivator, and photon-initiated photoacoustic streaming technique on removal of double and triple antibiotic pastes

INTRODUCTION

Photon-induced photoacoustic streaming (PIPS) is a novel technique used for the removal of material on root canal walls, such as bacteria and the smear layer. This study evaluated the efficacy of needle irrigation, the EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK), and PIPS on the removal of antibiotic pastes from an artificial groove created in a root canal.

METHODS

Root canal preparation was performed up to size #40 on 84 extracted single-rooted teeth using ProTaper rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland). The specimens were then split longitudinally, and 2 standardized grooves were prepared in the coronal and apical part of each segment. Double (DAP) and triple antibiotic pastes (TAP) were placed in the grooves for 4 weeks, and the root halves were reassembled. Needle irrigation, the EndoActivator System, and PIPS were used for the removal of DAP and TAP. The root segments were disassembled, and the amount of remaining antibiotic pastes was evaluated under a stereomicroscope at 20× magnification using a 4-grade scoring system. The data were evaluated statistically using Mann-Whitney U tests with a 95% confidence level (P = .05).

RESULTS

PIPS removed significantly more antibiotic pastes than the EndoActivator and needle irrigation (P < .001). The EndoActivator was superior to needle irrigation in removing antibiotic pastes (P < .001). There were no statistically significant differences between DAP and TAP and between coronal and apical thirds in their removing from artificially created grooves (P > .05).

CONCLUSIONS

PIPS was more effective in removing both DAP and TAP from artificial grooves in root canals than the EndoActivator System and needle irrigation. The EndoActivator was also more effective than needle irrigation. It is difficult to completely remove antibiotic pastes from root canals.