Success and Complication Rates of Revascularization Procedures for Immature Necrotic Teeth: A Systematic Review

Frequently, adolescents exhibit instances of immature necrotic teeth, which are identifiable by their slender root walls and unclosed root tips. The lack of a natural narrowing near the root's end creates difficulty when using standard endodontic procedures, making the effective sealing of the immature root canal difficult or impractical. Revascularization therapy surfaces as a prospective strategy for addressing the management of undeveloped, non-vital, immature, necrotic teeth. Notwithstanding this, apexification continues to hold prominence in the preferences of clinicians owing to its perceived predictability in treatment outcomes. A systematic investigation was conducted involving various search engines and databases, covering the period from 2001 to 2023. The main aim of this investigation was to find randomized clinical trials that compared the efficacy of revascularization therapy to apexification for treating immature necrotic teeth. The evaluation included a thorough examination of both clinical and radiographic outcomes assessing the success rates and complications. Out of the 850 identified articles, 15 studies were chosen for comprehensive analysis. Notable dissimilarities were not identified between the revascularization therapy and apexification groups concerning parameters such as rates of periapical healing, overall effectiveness/invalidation, and apical closure. However, concentrating on measurable factors, it became clear that the revascularization treatment group displayed a notable rise in root length compared to the apexification group. Both revascularization endodontic therapy and apexification demonstrated effectiveness in addressing periapical periodontitis healing and open apex closure. Pulp revascularization stood out for its notable efficacy in enhancing root elongation and thickening, all while having a reduced likelihood of treatment being deemed ineffective overall.

Stem Cells from the Apical Papilla (SCAPs): Past, Present, Prospects, and Challenges

Dental diseases occurring on young permanent teeth usually lead to the premature arrest of tooth root development. Sustained tooth root elongation is necessary to achieve the goal of long-term preservation of affected teeth. To this end, stem cell-based regenerative endodontic treatment has been regarded as one of the most promising strategies for treating young permanent teeth with pulp and periapical infections. Endogenous stem cells residing in the apical papilla, named stem cells from the apical papilla (SCAPs), have been intensively investigated due to their critical roles in pulp regeneration and root redevelopment. The present review summarizes advances in the field of SCAPs studies and discusses the challenges that need to be further addressed.

Multimodal Imaging of Dental Pulp Healing Patterns following Tooth Autotransplantation And Regenerative Endodontic Treatment

INTRODUCTION

Understanding the healing process of dental pulp after tooth autotransplantation (TAT) and regenerative endodontic treatment (RET) of immature teeth is important both clinically and scientifically. This study aimed to characterize the pattern of dental pulp healing in human teeth that underwent TAT and RET using state-of-the-art imaging techniques.

MATERIALS AND METHODS

This study examined four human teeth, two premolars that underwent TAT and two central incisors that received RET. The premolars were extracted after one year (case 1) and two years (case 2) due to ankylosis, while the central incisors were extracted after three years (cases 3 and 4) for orthodontic reasons. Nanofocus x-ray computed tomography was used to image the samples before being processed for histological and immunohistochemical analysis. Laser scanning confocal second harmonic generation imaging (SHG) was used to examine the patterns of collagen deposition. A maturity-matched premolar was included as a negative control for the histological and SHG analysis.

RESULTS

Analysis of the four cases revealed different patterns of dental pulp healing. Similarities were observed in the progressive obliteration of the root canal space. However, a striking loss of typical pulpal architecture was observed in the TAT cases, while a pulp-like tissue was observed in one of the RET cases. Odontoblast-like cells were observed in cases 1 and 3.

CONCLUSION

This study provided insights into the patterns of dental pulp healing after TAT and RET. The SHG imaging sheds light on the patterns of collagen deposition during reparative dentin formation.

Single-cell atlas of dental pulp stem cells exposed to the oral bacteria Porphyromonas gingivalis and Enterococcus faecalis

Introduction: Porphyromonas gingivalis and Enterococcus faecalis promote the development of pulpitis and periapical periodontitis. These bacteria are difficult to eliminate from the root canal systems, leading to persistent infection and poor treatment outcomes. We explored the response of human dental pulp stem cells (hDPSCs) to bacterial invasion and the mechanisms underlying the impact of residual bacteria on dental pulp regeneration. Methods: Single-cell sequencing was used to categorize the hDPSCs into clusters based on their response to P. gingivalis and E. faecalis. We depicted a single-cell transcriptome atlas of hDPSCs stimulated by P. gingivalis or E. faecalis. Results: The most differentially expressed genes in the Pg samples were THBS1, COL1A2, CRIM1, and STC1, which are related to matrix formation and mineralization, and HILPDA and PLIN2, which are related to the cellular response to hypoxia. A cell cluster characterized by high expression levels of THBS1 and PTGS2 was increased after P. gingivalis stimulation. Further signaling pathway analysis showed that hDPSCs prevented P. gingivalis infection by regulating the TGF-β/SMAD, NF-κB, and MAPK/ERK signaling pathways. Differentiation potency and pseudotime trajectory analyses showed that hDPSCs infected by P. gingivalis undergo multidirectional differentiation, particularly to the mineralization-related cell lineage. Furthermore, P. gingivalis can create a hypoxia environment to effect cell differentiation. The Ef samples were characterized by the expression of CCL2, which is related to leukocyte chemotaxis, and ACTA2, which is related to actin. There was an increased proportion of a cell cluster that was similar to myofibroblasts and exhibited significant ACTA2 expression. The presence of E. faecalis promoted the differentiation of hDPSCs into fibroblast-like cells, which highlights the role of fibroblast-like cells and myofibroblasts in tissue repair. Discussion: hDPSCs do not maintain their stem cell status in the presence of P. gingivalis and E. faecalis. They differentiate into mineralization-related cells in the presence of P. gingivalis and into fibroblast-like cells in the presence of E. faecalis. We identified the mechanism underlying the infection of hDPSCs by P. gingivalis and E. faecalis. Our results will improve understanding of the pathogenesis of pulpitis and periapical periodontitis. Furthermore, the presence of residual bacteria can have adverse effects on the outcomes of regenerative endodontic treatment.

Assessment of bone quality of apical periodontitis treated with MTA plug and regenerative endodontic techniques

Fractal analysis (FA) is a quantitative, objective and non-invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1-year follow-up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single-canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box-counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1-year follow-up (p < 0.01). However, there was no significant difference between the MTA plug and RET (p > 0.01). Significantly higher fractal dimension values were detected at 1-year follow-up in both MTA plug and RET cases (p < 0.01). However, the difference was not significant between the groups (p > 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity.

Effectiveness of Teeth Whitening after Regenerative Endodontics Procedures: An In Vitro Study

Discolouration resulting from regenerative endodontic procedures may have a negative impact on the quality of life of treated patients; therefore, it is recommended to minimize this risk by selecting appropriate scaffolds and barrier materials, and if discolouration occurs, the use of a simple, cost-effective and minimally invasive technique, such as whitening, should be considered. This in vitro study aimed to evaluate tooth discolouration after two- and single-visit regenerative endodontic procedures and the effectiveness of subsequent whitening procedures with carbamide peroxide. Two hundred bovine incisors were included in this study and divided into twenty groups based on the tested material combinations. Two groups were control groups, one with saline and the other group with blood. In the 12 groups, the experiment was designed to be consistent with the two-visit regenerative endodontic procedures. Triple antibiotic paste or calcium hydroxide were placed in the root canal, and then scaffolds (e.g., blood or platelet-rich fibrin) and barrier materials (Biodentine, OrthoMTA or MTA Repair HP) were applied after rinsing the disinfectant pastes. In the six groups that corresponded to the single-visit regenerative endodontic procedure, the use of a disinfectant paste was omitted. Subsequently, the specimens were bleached twice with carbamide peroxide at a 7-day interval. Colour change measurements were performed using a spectrophotometer (VITA Easyshade Compact 5.0, VITA Zahnfabrik, Bad Säckingen, Germany). Statistical analysis was performed with the Kruskal−Wallis H test, the independent t-test and t-test for related samples. Tooth discolouration was noticed after two- and single-visit regenerative endodontic procedures, except for the platelet-rich fibrin+MTA Repair HP group. After the first and second whitening procedures, all of the tested two- and single-visit regenerative endodontic procedures groups showed a change in the colour of the crown, which was noticeable to the naked eye (∆E > 3.3). When analysing the ∆E value between the first and second bleaching procedures, no changes in the colour of teeth were visually noticed in the calcium hydroxide and platelet-rich fibrin +MTA Repair HP groups (∆E < 3.3). Single-visit regenerative endodontic procedures are suggested if possible; however, if two-visit regenerative endodontic procedures are performed, it is recommended to use calcium hydroxide as the disinfectant paste because of the lower staining potential. In the context of discolouration, platelet-rich fibrin is advisable for use as a scaffold. The whitening procedure is worth considering, but does not guarantee a return to the original tooth colour, especially when triple antibiotic paste is used.

Tooth Bleaching of Discolorations Caused by Hydraulic Cements in Regenerative Endodontic Treatment: A 3-Year In Vitro Study

This study aimed to evaluate the color change caused by hydraulic cements after 3 years in vitro by simulating their use in regenerative endodontic treatment (RET) and to quantify the color change after external bleaching with 40% hydrogen peroxide at 1, 6, and 12 months of follow-up. Fifty teeth were treated simulating RET. Samples were distributed according to the hydraulic cement to be used (n = 10 per group): negative control (no cement), ProRoot-MTA, MM-MTA, TotalFill BC-RRM, or Biodentine. Three years after RET, two sessions of external bleaching with Opalescence Boost were performed. The color was measured in the cervical and incisal halves of the teeth at different time points: baseline, 3 years after performing RET, and after 1, 6, and 12 months after bleaching. The ΔL, Δa, and Δb were determined. A generalized linear model was used to compare color considering group and time. The ΔEab and the ΔE00 were calculated and the acceptability in color change was determined. Three years after RET, a reduction in lightness (negative ΔL values) was found in all groups. These values significantly increased 1 month after bleaching in all groups (p < 0.05) and reversed at 6 months. One month after bleaching, ΔE00 values (color difference tolerance (CIEDE2000)) ranged from very good (>3.6 ≤ 5.4) to excellent (>5.4). One year after bleaching, the color reverted to values similar to those found 3 years after RET. All groups became darker after RET. The color recovered and even improved compared with the baseline measurement after one month of bleaching but did not remain stable over time.

Mesenchymal Stem Cells Based Treatment in Dental Medicine: A Narrative Review

Application of mesenchymal stem cells (MSC) in regenerative therapeutic procedures is becoming an increasingly important topic in medicine. Since the first isolation of dental tissue-derived MSC, there has been an intense investigation on the characteristics and potentials of these cells in regenerative dentistry. Their multidifferentiation potential, self-renewal capacity, and easy accessibility give them a key role in stem cell-based therapy. So far, several different dental stem cell types have been discovered and their potential usage is found in most of the major dental medicine branches. These cells are also researched in multiple fields of medicine for the treatment of degenerative and inflammatory diseases. In this review, we summarized dental MSC sources and analyzed their treatment modalities with particular emphasis on temporomandibular joint osteoarthritis (TMJ OA).

Antibacterial Efficacy of Triple Antibiotic Medication With Macrogol (3Mix-MP), Traditional Triple Antibiotic Paste, Calcium Hydroxide, and Ethanol Extract of Propolis: An Intratubular Dentin Ex Vivo Confocal Laser Scanning Microscopic Study

INTRODUCTION

This study aimed to assess the effectiveness of antibacterial activity of medications used in regenerative endodontic treatment.

METHODS

Sixty-seven dentin cylinders of single-rooted teeth were contaminated with a culture of Enterococcus faecalis (ATCC 29212; American Type Culture Collection, Manassas, VA) for 5 days. Samples were divided into 1 control group and the following experimental groups according to the medication applied: traditional triple antibiotic paste (TAP), clindamycin-modified TAP (mTAP), triple antibiotic medication with macrogol (3Mix-MP), clindamycin-modified 3Mix-MP (m3Mix-MP), calcium hydroxide (CH), and ethanol extract of propolis (EEP). After 14 days, the medications were removed, and the samples were submitted to confocal laser scanning microscopic analysis to quantify the percentage of viable bacteria. The distribution of data was confirmed by the Shapiro-Wilk test. The Kruskal-Wallis and Dunn tests were used for intergroup comparisons, and the Wilcoxon test was used for comparison between superficial and deep antibacterial efficacy for the same medication. The level of significance was set at P < .05.

RESULTS

3Mix-MP and m3Mix-MP presented significantly higher antibacterial efficacy compared with the other tested medications (P < .05), except for mTAP. mTAP was more effective than TAP (P < .05). The antibacterial efficacy of EEP and CH did not differ significantly from TAP and mTAP (P > .05). All medications showed effective antibacterial action compared with the control group (P < .05).

CONCLUSIONS

3Mix-MP and m3Mix-MP, which present extremely high concentrations of antibiotics (1500 mg/mL), were not more effective than mTAP at the concentration recommended by the American Association of Endodontists (5 mg/mL). Moreover, CH and EEP were as effective as TAP and mTAP.

Ingrowth of Mineralized Tissue into the Root Canal of Immature Permanent Teeth after a Traumatic Injury: A Report of 3 Cases

The aim of this case series was to describe the endodontic management of 3 immature permanent teeth that sustained traumatic injuries and subsequently presented with complete ingrowth of mineralized tissue into the canal space. Ingrowth of bone/mineralized tissue into the canal has been considered a poor long-term outcome with an inherent risk of ankylosis. In cases 1 and 2, no endodontic treatment was undertaken, except for emergency management requiring splinting. The cases were followed for 36 and 23 months, respectively. No ankylosis was evident over the review period, and normal teeth eruption was apparent. In case 1, the tooth was treated orthodontically and was responsive to pulp sensibility testing. In both cases, there was an appearance of an internal periodontal ligament-like space on the inner root wall of the canal. In case 3, 2 years postinjury, pulp necrosis and apical periodontitis occurred, and the tooth was managed with regenerative endodontic treatment consistent with the European Society of Endodontology and the American Association of Endodontists guidelines/recommendations for a regenerative procedure. The case was followed for 8 years after regenerative endodontic treatment. No ankylosis was noted with normal eruption of the teeth. The tooth was responsive to pulp sensibility testing despite the ingrowth of mineralized tissue, which was confirmed clinically.

Efficiency of Teeth Bleaching after Regenerative Endodontic Treatment: A Systematic Review

The aim of this review is to evaluate of effectiveness of bleaching procedures used to treat discolored teeth subsequent to regenerative endodontic procedures (REPs) based on the review of in vitro and in vivo studies. This literature review was carried out according to the PRISMA guidelines. Four databases (PubMed, Scopus, the Cochrane Library, and Web of Science databases) were searched electronically, until 30 January 2020 without a year limit. The quality of studies was assessed using a modified methodological index for non-randomized studies. After analyzing 1405 studies, 6 in vitro and 9 in vivo studies were eligible for this review. In in vitro studies, effectiveness of bleaching was assessed in teeth discolored by antibiotic pastes, blood, and barrier materials in various combinations. In all analyzed studies, bleaching was effective in teeth discolored by antibiotic pastes as well as by blood and barrier materials. Of 26 treated teeth in the in vivo studies, 17 teeth were bleached successfully. In six cases, there was improvement of the shade. In three cases, bleaching was not sufficient. Bleaching material, techniques, and times differed between studies. Whitening of discolored teeth after REPs is achievable. However, to establish precise guidelines, further long-term clinical studies should be performed.

Viability and Stimulation of Human Stem Cells from the Apical Papilla (hSCAPs) Induced by Silicate-Based Materials for Their Potential Use in Regenerative Endodontics: A Systematic Review

Blood clot formation in the apical third of the root canal system has been shown to promote further root development and reinforcement of dentinal walls by the deposition of mineralized tissue, resulting in an advancement from traditional apexification procedures to a regenerative endodontic treatment (RET) for non-vital immature permanent teeth. Silicate-based hydraulic biomaterials, categorized as bioactive endodontic cements, emerged as bright candidates for their use in RET as coronal barriers, sealing the previously induced blood clot scaffold. Human stem cells from the apical papilla (hSCAPs) surviving the infection may induce or at least be partially responsible for the regeneration or repair shown in RET. The aim of this study is to present a qualitative synthesis of available literature consisting of in vitro assays which analyzed the viability and stimulation of hSCAPs induced by silicate-based hydraulic biomaterials. A systematic electronic search was carried out in Medline, Scopus, Embase, Web of Science, Cochrane and SciELO databases, followed by a study selection, data extraction, and quality assessment following the PRISMA protocol. In vitro studies assessing the viability, proliferation, and/or differentiation of hSCAPs as well as their mineralization potential and/or osteogenic, odontogenic, cementogenic and/or angiogenic marker expression in contact with commercially available silicate-based materials were included in the present review. The search identified 73 preliminary references, of which 10 resulted to be eligible for qualitative synthesis. The modal materials studied were ProRoot MTA and Biodentine. Both bioceramic materials showed significant positive results when compared to a control for hSCAP cell viability, migration, and proliferation assays; a significant up-regulation of hSCAP odontogenic/osteogenic marker (ALP, DSPP, BSP, Runx2, OCN, OSX), angiogenic growth factor (VEGFA, FIGF) and pro-inflammatory cytokine (IL-1α, IL-1β, IL-6, TNF-α) expression; and a significant increase in hSCAP mineralized nodule formation assessed by Alizarin Red staining. Commercially available silicate-based materials considered in the present review can potentially induce mineralization and odontogenic/osteogenic differentiation of hSCAPs, thus prompting their use in regenerative endodontic procedures.

Clinical, Radiographic, and Histologic Outcome of Regenerative Endodontic Treatment in Human Teeth Using a Novel Collagen-hydroxyapatite Scaffold

INTRODUCTION

Histologic examination of teeth after regenerative endodontic treatment (RET) shows that the type, quality, and quantity of tissues formed in the root canal space are not predictable. The aim of this study was to examine clinically, radiographically, and histologically the outcome of RET in immature noninfected human teeth using SynOss Putty (Collagen Matrix Inc, Oakland, NJ) as a scaffold.

METHODS

Three pairs of maxillary/mandibular first premolars in 3 patients scheduled for extraction were included. Sensibility tests confirmed the presence of vital pulps. After informed consent, anesthesia, and rubber dam isolation, the pulps were removed. RET was performed using the following scaffolds: SynOss Putty + blood in both teeth in patient #1, SynOss Putty with or without blood in patient #2, and SynOss Putty + blood or blood only in patient #3. After a follow-up period of 2.5-7.5 months, the teeth were clinically and radiographically evaluated, extracted, and examined histologically.

RESULTS

Patients remained asymptomatic after treatment. Radiographic examination of the teeth showed signs of root development after treatment. In teeth treated with SynOss Putty + blood, histologic examination showed formation of intracanal mineralized tissue around the scaffold particles solidifying with newly formed cementumlike tissue on the dentinal walls. The tooth treated with SynOss Putty without blood showed the formation of a periapical lesion. The tooth treated with a blood clot only showed tissues of periodontal origin growing into the root canal space.

CONCLUSIONS

SynOss Putty + blood showed a predictable pattern of tissue formation and mineralization when used as a scaffold for RET in human immature noninfected teeth. The newly formed mineralized tissue solidifies with newly formed cementum on the dentinal walls.

Effect of varying durations of intracanal medicament application used in regenerative endodontic treatment on the push-out bond strength of a novel cement: NeoMTA Plus

Aim:

The aim of the present study was to evaluate the effect of varying durations of intracanal medicament application used in regenerative endodontic treatment on the push out the bond strength of a novel cement-NeoMTA Plus.

Materials and Methods:

A total of 60 extracted single-rooted maxillary anterior teeth were decoronated. Roots were instrumented uniformly until Peeso Reamer size #5 to simulate open apices. A total of 60 roots were then divided into four groups according to intracanal medicaments used (n = 15): Group 1: Triple antibiotic paste (TAP); Group 2: Double antibiotic paste (DAP); Group 3: Calcium hydroxide paste (CH); and Group 4 (control): No medicament. Samples were kept in saline solution for 2, 4, and 12 weeks, after which time five roots were selected randomly from each group, representing the samples of each time point. After removal of the medicaments, NeoMTA Plus was placed into 8 mm of the coronal third of the roots and samples were incubated. Roots were sectioned to obtain 2 discs per root (n = 10). A push-out test was used to measure the sealing efficacy of NeoMTA Plus. Data were analyzed using a one-way ANOVA followed by Tukey's pairwise comparisons.

Results:

CH, DAP, and TAP application resulted in significantly lower values of the push-out bond strength of NeoMTA Plus after 12 weeks compared to 2 weeks (P < 0.05).

No significant differences were found between the time points in the control group (P > 0.05).

DAP showed lowest push-out bond strength.

Conclusion:

CH, DAP, and TAP cause an alteration in dentinal surface properties leading to negative effect on bond strength of NeoMTA Plus. The effect is more evident in DAP and as treatment time is prolonged. The type and duration of medicament application have to be monitored to achieve a maximum therapeutic value as well as to avoid compromise on the coronal seal.

Management of an Immature Necrotic Permanent Molar with Apical Periodontitis Treated by Regenerative Endodontic Protocol Using Calcium Hydroxide and MM-MTA: A Case Report with Two Years Follow Up

Traditionally, immature teeth diagnosed with necrotic pulp and periapical periodontitis were treated by apexification with long-term calcium hydroxide or in one session with mineral trioxide aggregate (MTA) or Biodentine apical plug. However, these teeth become fragile and susceptible to root fracture. Regenerative endodontic procedure is a new therapeutic approach that promotes continuation of root growth in immature necrotic teeth potentially preventing root fracture. Only few case reports have shown the success of this procedure on molar cases. The current case report demonstrates a regeneration of a lower first molar with necrotic pulp and chronic apical abscess treated with Micro Mega-MTA (MM-MTA), a new endodontic biomaterial that has not been described previously. Calcium hydroxide was used as an intracanal medicament for two weeks. Next, calcium hydroxide was removed and after blood clot creation, MM-MTA^® was placed over it. Apical healing and continuation of root growth were evident at nine months follow-up. CBCT at two years follow-up confirmed apical closure and complete healing. This case shows that a regenerative endodontic procedure for management of an immature necrotic permanent molar is feasible and can be successfully done using Ca(OH)₂ and MM-MTA.

Effect of Bioceramic Materials on Proliferation and Odontoblast Differentiation of Human Stem Cells from the Apical Papilla

INTRODUCTION

In regenerative endodontic treatment (RET), practitioners favor the placement of bioceramics as sealing materials over blood clots. It is important to understand the interaction between sealing material and cells in the root canal. The purpose of this study was to compare the effectiveness of various bioceramic materials (ProRoot MTA [Dentsply, Tulsa, OK], Biodentine [Septodont, Saint-Maur-des-Fossés, France], and RetroMTA [BioMTA, Seoul, Korea]) as sealing materials in RET for the proliferation and differentiation of stem cells from the apical papilla (SCAPs).

METHODS

SCAPs were seeded at 20,000 cells/well and cultured with soluble agents of testing materials through a transwell culture plate. The proliferation of SCAPs was investigated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on days 1, 3, 7, and 14 of testing. Alizarin red staining and quantitative real-time polymerase chain reaction were used for SCAP differentiation at different time points (1, 7, 14, and 21 days). The odontoblast genes expressed are dentin matrix acidic phosphoprotein 1, dentin sialophosphoprotein, osteocalcin, and matrix extracellular phosphoglycoprotein, which were used in this study. The SCAPs were cultured in odonto/osteogenic induction medium and also contacted soluble agents from the testing materials.

RESULTS

All 3 tested biomaterials induced SCAP proliferation. The Biodentine, ProRootMTA, and RetroMTA groups showed significant SCAP proliferation on days 7 and 14 compared with the control. In regard to odontoblastic differentiation, only Biodentine showed positive alizarin red staining. The highest expressions of dentin matrix acidic phosphoprotein 1, dentin sialophosphoprotein, and matrix extracellular phosphoglycoprotein were found on day 21 in the Biodentine group. The expression of osteocalcin was found to be significant on day 7.

CONCLUSIONS

Biodentine, ProRootMTA, and RetroMTA can induce SCAP proliferation. Biodentine induced significant SCAP differentiation among the 3 materials.

A Novel Conservative Approach Combining "SealBio" and "Surgical Fenestration" for Healing of Large Periapical Cystic Lesions of Endodontic Origin: A Pilot Study

OBJECTIVES

To evaluate the treatment outcome of large periapical cystic lesions treated by combining two novel, conservative approaches, "SealBio" and "Surgical Fenestration".

MATERIALS AND METHODS

Five cases (4M:1F, age range 14-38 years, mean age 24.5 years) of large periapical cystic lesions, diagnosed on clinical and radiographic examination, were included in the study. After informed consent, endodontic treatment was initiated; chemo-mechanical preparation and intra-canal dressing of calcium hydroxide was given. At the next sitting after one week, further disinfection root canals was done by "apical clearing", "apical foramen widening" and irrigation. A cotton pellet was kept in the access cavity. After local anaesthesia, full thickness muco-periosteal flap was reflected and the thinned out bone was removed with bone rongers, a small piece of cystic lining was excised and the cystic cavity was copiously flushed with Betadine solution. The remaining cystic lining was gently curetted and the flap was sutured back. "SealBio" was performed after gentle irrigation with saline and intentional over instrumentation. A calcium sulphate based cement was pushed in the cervical third of the canal and the access opening was sealed with glass ionomer cement. Patient was prescribed antibiotics and anti-inflammatory drugs for 5 days and sutures were removed after 7 days. Patients were followed up clinically and radiographically at regular intervals.

CONCLUSIONS

In this pilot study, treatment outcome after combined technique of "SealBio" and "Surgical fenestration" was found to be highly effective in healing of large periapical cystic lesions. It was simple to perform and very conservative treatment; it required minimal bone removal, obviated the need for complete cyst enucleation, apicectomy and retrograde filling.

A regeneration-based, nonobturation root-canal treatment for fully-mature teeth: Six years' experience with "SealBio"

OBJECTIVES

To provide scientific evidence on the outcome of a large number of cases treated by SealBio over the longer follow-up period.

MATERIALS AND METHODS

One hundred and thirty-four teeth in 116 patients presenting with pulp and periapical disease were randomly recruited between 2009 and 2014. SealBio was performed, and cases were followed up at regular intervals up to 6-year.

RESULTS

Of the total 134 teeth treated, 16 teeth could not be followed up and 9 cases failed (7.62% of cases). In only 4 cases (approximately 3.38% of cases), the failure could be directly attributed to endodontic causes. In the remaining 5 cases, coronal leakage from under the crown margins or dislodged restoration was found after 3-5 years of treatment.

CONCLUSIONS

SealBio was found to be a successful, nonobturation, regeneration-based endodontic treatment protocol. By cell homing of endogenous stem cells, a biological seal rather than an artificial seal with gutta-percha and sealer cement is possible to achieve. It is highly cost saving and easier to perform, in addition to other advantages, such as retreatment is much simpler, and postcore restoration is possible after SealBio treatment.

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.

Histologic comparison between platelet-rich plasma and blood clot in regenerative endodontic treatment: an animal study

INTRODUCTION

In regenerative endodontic treatment (RET) for immature permanent tooth, better treatment results could be obtained by applying platelet-rich plasma (PRP) as the scaffold rather than the blood clot. The goal of this study was to compare the histologic differences between using PRP and blood clot in RET.

METHODS

Three 6-month-old beagles each carrying 9 premolars with double root canals were randomly assigned to the PRP group, blood clot group, or negative control group. All experimental teeth suffered apical periodontitis, and RET was performed. In the blood clot group, bleeding was induced from the periapical tissues to fill the canal space. In the PRP group, autologous PRP was injected into each root canal. The animals were sacrificed 3 months later. Histologic sections were stained with hematoxylin-eosin. Statistical analysis was performed by the Fisher exact test, with the significance set at 0.05.

RESULTS

With the ingrowth of cellular cementumlike tissues, the canal wall was thickened, and the apical apex was closed in both the PRP and blood clot groups. Cementocytelike cells were present in the newly formed tissues. Meanwhile, no statistical difference was found in both experimental groups for the average percentage of apical closure, new tissue formation, and pulplike tissue formation. Noticeably, a large number of inflammatory cells were present in some root canals in both groups although the postoperative radiograph revealed the disappearance of periapical radiolucency.

CONCLUSIONS

PRP application could be an option for clinical cases in which little or no bleeding were found when irritating the apical tissue during RET.