Regenerative Endodontic Procedures for the Treatment of Necrotic Mature Teeth with Apical Periodontitis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

IntroductionRegenerative endodontic procedures (REPs) are intended to repair and regenerate part of the pulp-dentin complex. The aim of this study was to systematically appraise the existing evidence on the effectiveness of REPs on mature teeth with pulp necrosis and apical periodontitis.MethodsElectronic database and hand searches were performed on 8 databases of published and unpublished literature from inception to January 3, 2021, for the identification of randomized controlled trials (RCTs) or prospective clinical trials. The related key words included “regenerative,” “pulp revascularization,” “revitalization procedure,” and “necrotic mature teeth.” A random effects meta-analysis was conducted assessing success as the main outcome treatment. Risk of bias was assessed through the Cochrane Risk of Bias 2.0 tool, and the quality of the evidence was assessed with the Grading of Recommendations Assessment, Development and Evaluation approach.ResultsOf the 337 initial hits, 4 RCTs were eligible for inclusion, whereas 3 were included in the quantitative synthesis. Overall, there was no difference in the relative risk for a successful/unsuccessful treatment outcome between REPs or conventional treatment (3 studies, relative risk = 1.03; 95% confidence interval, 0.92–1.15; P = .61; heterogeneity I² = 0.0%, P = .53; prediction interval = 0.51–2.09). Risk of bias ranged from low to raising some concerns, whereas the quality of the evidence was graded as moderate.ConclusionsBased on moderate-quality evidence, REPs appear as a viable treatment alternative for mature necrotic teeth with periapical lesions at present. Furthermore, well-designed RCTs might also provide confirmatory evidence in this respect while also framing a backbone for standardization of the therapeutic protocol of REPs.     

Diagnosis of Vertical Root Fractures by Cone-beam Computed Tomography in Root-filled Teeth with Confirmation by Direct Visualization: A Systematic Review and Meta-Analysis

IntroductionThe purpose of this review was to determine the diagnostic accuracy of cone-beam computed tomographic (CBCT) imaging in detecting vertical root fractures (VRFs) in root-filled teeth compared with a reference standard (direct visualization).MethodsElectronic searches were performed in Medline, Scopus, Cochrane, and gray literature for English language articles until June 2020. Prospective and retrospective clinical studies using CBCT imaging to diagnose VRFs in root-filled teeth were included. Case reports and in vitro studies were excluded. The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess the risk of bias and applicability concerns. Meta-analysis was performed using Stata 16.1 software (StataCorp, College Station, TX) via the MIDAS v.3.0 package and METANDI module. Publication bias was evaluated using Deeks’ funnel plot analysis. Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) was performed to evaluate the certainty of evidence. This systematic review was registered in the Open Science Framework (10.17605/OSF.IO/7JKE2).ResultsEight articles were included in this systematic review and meta-analysis. Risk of bias assessment showed that 5 articles in the patient selection domain had low risk of bias with low applicability concern. In the index test and reference standard domains, 7 articles had moderate risk of bias with moderate applicability concern. Three articles had high RB in the flow and timing domain. There was no publication bias. CBCT imaging had a pooled sensitivity and specificity of 0.78 (95% confidence interval [CI], 0.64–0.88) and 0.80 (95% CI, 0.63–0.91), respectively, and an accuracy of 0.86 (95% CI, 0.83–0.89). CBCT imaging also had pooled positive and negative likelihood ratios of 4 and 0.2, respectively. In GRADE analysis, the quality of evidence was low for sensitivity and moderate for specificity when CBCT imaging was used for the diagnosis of VRF.ConclusionsThe overall quality assessment of the included articles showed that in the patient selection domain, the risk of bias was low, and it was moderate in the index test and reference standard domains. Evidence from this systematic review and meta-analysis indicates that CBCT imaging is still not a good tool for diagnosing VRFs in root-filled teeth compared with direct visualization.     

Regenerative Endodontic Therapy in Mature Teeth Using Human-Derived Composite Amnion-Chorion Membrane as a Bioactive Scaffold: A Pilot Animal Investigation

IntroductionHuman-derived composite amnion-chorion membrane (ACM) has been used for various regenerative treatments. The aim of this pilot study was to investigate the effectiveness of the ACM as a scaffold for pulp regeneration in mature canine teeth.MethodsA total of 24 roots from mature premolars in dogs were included for regenerative procedures using blood clots (BC) (group 1, n = 8), collagen membrane (CM) (group 2, n = 8), and ACM (group 3, n = 8). Each tooth was left open through a buccal access to induce root canal infection and inflammation. The root canals were disinfected with 1.5% NaOCl and calcium hydroxide intracanal medicament. After 2 weeks, bleeding was evoked to induce blood clot formation (group 1) or before the placement of the membranes (groups 2 and 3). After 12 weeks, the animals were euthanized for histologic assessment. The histologic data including intracanal fibrous connective tissue, odontoblast-like cell lining, intracanal mineralized tissue, periapical inflammation, and apical closure were qualitatively and quantitively analyzed.ResultsHistologic analysis revealed that intracanal fibrous connective tissue was identified in all groups, but a higher volume of the fibrous tissues was formed in the ACM group. Odontoblast-like cells were only observed in the ACM group. The intracanal mineralized tissue was observed only in the BC and CM groups. The BC group showed more periapical inflammation than the ACM group (P < .05). Apical closure was more often found in the CM group than the BC group (P < .05).ConclusionsMore intracanal fibrous tissue and odontoblast-like cell lining, and less periapical inflammation were observed after regenerative endodontic treatment in mature teeth using the ACM than blood clot alone or blood clot with collagen membrane. The use of the ACM may be useful for a cell-homing–based pulp regeneration in mature teeth.     

Differences in the biomechanical behaviors of natural teeth and dental implants

ObjectiveThe lack of a PDL, which acts as an energy absorber, is a contributor to implants’ early failure; however, these discrepancies are not well understood because of limited in vivo research. This study investigated the discrepancy in biomechanical behaviors between natural teeth and dental implants by detecting micro-movements in vivo.MethodsWe designed a device that could measure precisely mechanical behaviors such as creep, stress relaxation, and hysteresis by using load–control displacement on teeth and implants. We also compared energy dissipation between natural teeth and dental implants by subtracting the area of the hysteresis loop of natural teeth from that of dental implants.ResultsBiphasic curves with an initial phase of rapid response and a subsequent phase of slow response were confirmed in creep and stress relaxation curves for the load–time relationship in natural teeth. By contrast, the behavior of creep or stress relaxation was less prominent when the dental implants were tested. We observed that the periodontal ligament under an axial intrusive load of 300 g in a loading rate 3 g/s could dissipate the energy of 7.35 ± 1.18 × 10^?2 mJ, approximately 50 times that of the dental implants (1.47 ± 1.22 × 10^?3) with statistically significant (p < 0.05).SignificanceWe confirmed natural teeth could achieve greater energy dissipation compared to dental implants, which owe to that natural teeth exhibited fluid and viscoelastic properties.     

iRoot BP Plus在成熟恒牙活髓保存治疗中的疗效分析

目的 评价iRoot BP Plus用于成熟恒牙活髓保存治疗(直接盖髓术和部分活髓切断术)的临床疗效.方法 选取120例共120颗因龋露髓成熟恒牙牙髓炎患者,随机分为A(直接盖髓术)、B(部分活髓切断术)和C(根管治疗术)3组,每组40例,术后第3、6、12个月复查,综合评价3组的疗效、发生不良反应和患者满意度的差异.结果 3组患牙治疗效果均较好:术后3个月,A、B、C组的治疗成功率分别是92.5％、97.5％、95.0％;术后6个月,3组分别是90.0％、95.0％、92.5％;术后12个月,3组分别是90.0％、95.0％、90.0％.在不同时间段,3组之间治疗的成功率和术后不良反应发生率的差异均无统计学意义(P>0.05).A、B两组的患者综合满意度明显高于C组(P<0.05).结论 iRoot BP Plus用于因龋露髓的成熟恒牙活髓保存治疗,疗效可靠,可以避免根管治疗所产生的术后并发症,值得临床推广.     

Structural integrity of extracted teeth restored using three different post-and-core systems: An in vitro comparative study

AimThe objective of the study was to assess the in vitro fracture resistance of endodontically treated teeth restored using different post-and-core materials.Materials and methodsExtracted human mandibular premolars (n = 36) were extracted teeth and equally distributed into four (4) treatment groups: cast metal post-and-core, milled zirconia post-and-core, pre-fabricated post with composite resin core and control group. These samples were then each subjected to the load to fracture test using a universal testing machine. Fracture resistance data were compared among groups by analysis of variance and Fisher’s exact test.ResultsThe highest mean fracture resistance value was observed in the zirconia post-and-core treatment group (1567.26 ± 317.66 N), followed by the cast metal (1355.92 ± 621.56 N) and lastly the pre-fabricated post with composite resin core (725.67 ± 251.05 N) treatment group. Differences among groups were not statistically significantly different (P = 3.77).ConclusionEndodontically treated mandibular premolars with a zirconia post-and-core system exhibited the highest robustness against structural failure based on its mean fracture resistance value. In addition, extracted teeth restored with cast post-and-core resisted a greater stress load than those restored with fiber-reinforced posts. Zirconia showed a more favorable fracture mode than the other restorations.     

磨牙区使用角度螺丝一体冠不同全瓷材料修复种植单冠：1年前瞻性半口自身对照研究

目的 评价种植体支持的角度螺丝一体冠不同全瓷材料修复单冠在随访1年后的临床效果。方法 纳入13例上颌或下颌磨牙区双侧对称缺失的患者,每例患者接受两侧种植治疗。同一患者使用相同尺寸的2颗种植体。3~6个月后采用角度螺丝通道一体全瓷冠修复,每例患者的修复体分为全锆组和传统组。戴牙后即刻和12个月后进行X线检查,记录患者对修复体使用1年后的美学、功能评分及并发症。采用SAS 9.4软件对数据进行统计学分析。结果 13例患者修复后12个月的种植体成功率为100%。美学评价与功能评价在全锆组和传统组无显著差异（P>0.05）。全锆组边缘骨吸收为（-0.117±0.157）mm,传统组边缘骨吸收为（-0.141±0.153）mm,差异无统计学意义（P>0.05）。结论 在本研究范围内,磨牙区使用2种全瓷修复方式的螺丝通道一体冠临床效果良好,全锆冠与传统全瓷冠修复效果无显著差异。     

多学科综合治疗挽救重度牙周炎患牙的临床观察（附1例5年随访报告）

重度牙周炎患者多存在深牙周袋及严重牙槽骨吸收的患牙,常判定为“预后无望”,而此类患牙的临床处置一直以来都面临挑战。此外,伴牙列缺损及错牙合畸形的重度牙周炎患者临床中常需要应用多学科综合治疗,以达到牙周健康、恢复功能、改善美观的目标。文章完整展示1例应用牙周-正畸-种植修复综合治疗的重度牙周炎病例,挽救重度牙周炎患牙,并获得稳定的治疗效果,为临床诊疗此类问题积累经验。     

Influence of the coronal restoration on the outcome of endodontically treated teeth

Abstract

Objective: The tooth weakens due to removal of hard tissue during an endodontic procedure. Many dentists find it difficult to choose between different coronal restorations after root canal treatment (RCT). Studies show that the coronal restoration may affect the endodontic prognosis. This student-based study had three aims. (1) Examine the choice of coronal restoration of endodontically treated teeth at a Scandinavian dental school, (2) examine the survival of these restorations and (3) evaluate the influence of the coronal restoration on the outcome of the RCT.

Material and methods: Radiographic and clinical examination was performed on 127 posterior teeth. The quality of the root canal treatment and the periapical status (PAI-index) were evaluated.

Results: 43.8% of the teeth were restored with an indirect coronal restoration and 47.2% with a direct coronal restoration. The period from finished root canal treatment until placement of a permanent coronal restoration was significantly longer for an indirect restoration than a direct restoration. The teeth treated with a PAI score of 1 and 2 following pulpectomy, necrotic pulp treatment and endodontic retreatment was 93.8%, 82.6% and 69.4%, respectively.

Conclusion: There was no significant association between choice of coronal restoration and PAI-score.