Repair versus Replacement of Defective Direct Dental Restorations: A Multinational Cross-sectional Study with Meta-Analysis.

OBJECTIVES: When dental practitioners encounter a defective restoration, they are faced with a crucial decision whether to repair or replace it. This study aims to explore international preferences for repair procedures and the clinical steps taken during the repair process. METHOD: An 11-question survey was distributed to dentists across 21 countries via different platforms. The survey comprised two sections: the first included five questions aimed at gathering demographic information, while the second consisted of six questions focusing on participants' practices related to the repair of composite or amalgam restorations A meta-analysis was employed to ascertain the pooled odds ratio of repairing versus replacement. The statistical analysis was carried out using the RevMan 5.3 program and forest plots were generated using the same program to visualize the results. RESULTS: The survey was completed by 3680 dental practitioners. The results indicated a strong tendency to repair defective composite restorations (OR: 14.23; 95% CI: 7.40, 27.35, p<0.001). In terms of amalgam, there was a significant tendency to replace the restorations (OR: 0.19; 95% CI: 0.12, 0.30, p<0.001). When repairing restorations, the most common protocols were etching with orthophosphoric acid and creating an enamel bevel, regardless of the restorative material used. CONCLUSION: The findings of this study indicate that there exists a knowledge gap among dental practitioners regarding restoration repair. It is imperative that dental practitioners receive proper education and training on restoration repair, to ensure the usage of adequate protocols and restoration survival.

The response of dual-species bacterial biofilm to 2% and 5% NaOCl mixed with etidronic acid: A laboratory real-time evaluation using optical coherence tomography.

AIM: The addition of etidronic acid (HEDP) to sodium hypochlorite (NaOCl) could increase the antibiofilm potency of the irrigant, whilst maintaining the benefits of continuous chelation. Studies conducted so far have shown that mixing HEDP with NaOCl solutions of relatively low concentration does not compromise the antibiofilm efficacy of the irrigant. However, the working lifespan of NaOCl may decrease resulting in a reduction of its antibiofilm efficacy over time (efficiency). In this regard, continuous irrigant replenishment needs to be examined. This study investigated the response of a dual-species biofilm when challenged with 2% and 5% NaOCl mixed with HEDP for a prolonged timespan and under steady laminar flow. METHODOLOGY: Dual-species biofilms comprised of Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were grown on human dentine discs in a constant depth film fermenter (CDFF) for 96 h. Biofilms were treated with 2% and 5% NaOCl, alone or mixed with HEDP. Irrigants were applied under steady laminar flow for 8 min. Biofilm response was evaluated by means of optical coherence tomography (OCT). Biofilm removal, biofilm disruption, rate of biofilm loss and disruption as well as bubble formation were assessed. One-way anova, Wilcoxon's signed-rank test and Kruskal-Wallis H test were performed for statistical analysis of the data. The level of significance was set at a ≤.05. RESULTS: Increasing NaOCl concentration resulted in increased biofilm removal and disruption, higher rate of biofilm loss and disruption and increased bubble formation. Mixing HEDP with NaOCl caused a delay in the antibiofilm action of the latter, without compromising its antibiofilm efficacy. CONCLUSIONS: NaOCl concentration dictates the biofilm response irrespective of the presence of HEDP. The addition of HEDP resulted in a delay in the antibiofilm action of NaOCl. This delay affects the efficiency, but not the efficacy of the irrigant over time.

Cervical Level Biological Repair of the Access Opening after Regenerative Endodontic Procedures: Three Cases with the Same Repair Pattern.

INTRODUCTION: This article describes the regenerative endodontic procedures applied in 3 cases of maxillary incisor necrosis that resulted in continuous root development, dentinal wall thickening, and cervical level biological repair of the access openings that was verified radiographically in 2 cases and clinically in 1 case. METHODS: Three maxillary central incisors in 2 different patients were rendered necrotic after having dentin enamel fracture traumatic dental injuries. All teeth were treated with single- or multiple-visit regenerative endodontic procedures. RESULTS: The 5- and 9-year follow-up evaluations revealed similar continuous root development, dentin wall thickening, and hard tissue biological repair of the wide access cavities. In the 9-year follow-up case, the calcium silicate cement was removed because of unacceptable discoloration. The hard tissue biological repair was visualized under the microscope and checked for its continuity with the axial walls, its resistance to displacement, and the presence of possible gaps. The repair tissue seemed to be yellowish in appearance with some brown niches of irregular texture, did not have detectable gaps, was firmly connected with the axial dentinal walls through a demarcated white line, and resisted all displacement forces applied. The tooth was restored with bonded composite resin restoration after internal bleaching. The 10-year follow-up revealed satisfactory esthetics and uneventful soft and hard tissue healing. CONCLUSIONS: Cervical-level hard tissue repair of the access opening after the application of regenerative endodontic procedures in necrotic immature maxillary incisors might reinforce the weakened tooth structure to a great extent and warrants further investigation.

Effect of Dentin Matrix Components on the Mineralization of Human Mesenchymal Stromal Cells.

IMPACT STATEMENT: This research has been conducted with the aim to contribute to the development of treatment modalities for the reconstruction of lost/damaged mineralized tissues. Currently, determining the most appropriate stromal cell population and signaling cues stands at the core of developing effective treatments. We provide new insights into the effect of innate inductive cues found in human dentin matrix components, on the osteogenic differentiation of various human stromal cell types. The effects of dentin extracellular matrix components on umbilical cord mesenchymal stromal cells have not been investigated before. The findings of this study could underpin translational research based on the development of techniques for mineralized tissue engineering and will be of great interest for the readership of Tissue Engineering Part A.

Secreted products of oral bacteria and biofilms impede mineralization of apical papilla stem cells in TLR-, species-, and culture-dependent fashion.

Regenerative endodontics exploits the mineralization potential of stem cells from the apical papilla (SCAPs) in order to promote root maturation of permanent immature teeth. SCAPs may encounter post-disinfection residual bacteria either in planktonic or in biofilm growth mode. Bacterial components bind to Toll-like receptors (TLRs) and trigger pro-inflammatory responses. We hypothesized that biofilm-triggered TLR activation affects the mineralization potential of human SCAPs. SCAPs were challenged with conditioned media derived from standardized dual-species biofilms and planktonic bacterial cultures and their inflammatory status and mineralization capacity were studied. Bacterial products from both growth modes (planktonic vs. biofilm) compromised cell viability, proliferation and mineralization capacity of SCAPs, but in a species- and growth mode-dependent fashion. While TLR4 expression remained unaffected, TLR2 expression was upregulated coinciding with a pro-inflammatory activation of SCAPs. Moreover, TLR and its downstream TGF-ß-associated kinase (TAK1) appeared to be blocking mineralization, as inhibition of these factors restored it. In conclusion, bacterial products promoted the pro-inflammatory status and inhibited mineralization of human SCAPs in a TLR-, species-, and culture-dependent fashion. TLR2 emerged as the pivotal mediator of these responses and further research is warranted towards the judicious manipulation of SCAPs in order to modify the untoward events of TLR-priming and signaling.

Bone regeneration in critical-size calvarial defects using human dental pulp cells in an extracellular matrix-based scaffold.

The rat calvarial defect is an established model to evaluate craniofacial bone regeneration using cell-scaffold biocomplexes. Dental pulp harbors stem cells with significant osteogenic properties. Extracellular matrix (ECM)-like scaffolds simulate the environment that cells observe in vivo. In the present study, we evaluated the osteogenic effect of a biocomplex of human dental pulp cells and a hyaluronic-based hydrogel scaffold in calvarial defects of immunocompetent rats. Dental pulp cells at the 2nd passage were characterized by flow cytometry, osteodifferentiated ex vivo for 4 days and the whole population was encapsulated in the synthetic ECM matrix. Cell vitality was verified 24 h upon encapsulation. 5 mm calvarial defects were created in 30 male rats and filled with the biocomplex, the scaffold alone, or left untreated. Histological evaluation at 8 weeks showed incomplete bone regeneration in all groups. The scaffold was not fully degraded and entrapped cells were detected in it. Histomorphometry showed statistically significant superior new bone formation in the biocomplex-treated group, compared to the two other groups. The present study provides evidence that the whole population of human dental pulp cells can advance bone healing when transplanted in immunocompetent animals and highlights the importance of proper scaffold degradation in cell-driven bioengineering treatments.

Influence of specialty training and experience on endodontic decision making.

INTRODUCTION: The purpose of this study was to compare decision-making choices among dentists with different levels of training. METHODS: Scanned periapical radiographs and a leaflet with relevant information of 17 endodontically treated teeth were mailed to 40 undergraduate students, 25 general practitioners, 20 postgraduate students, and 40 endodontists. All teeth were symptom-free. The hypothetical scenario referred to patients who sought treatment for first time and had noncontributory medical history. Five treatment options were given for each situation: (1) Extraction, (2) Surgical Retreatment, (3) Nonsurgical Retreatment, (4) Wait and See, and (5) No Therapy. Statistical analysis was performed by using multinomial logistic regression models. RESULTS: The overall response rate was 70.4%, with endodontists exhibiting the lowest response. The undergraduates gave 4 or 5 treatment solutions for all cases, in contrast to endodontists, who gave 2 or 3 treatment solutions in a percentage of 82%. Nonsurgical Retreatment predominated among the participants' choices. Significant differences were detected in (1) Extraction for postgraduate students (P = .008) and endodontists (P = .001), (2) Surgical Retreatment for general practitioners (P = .002), postgraduate students (P = .002), and endodontists (P = .001), and (3) Wait and See for postgraduate students (P = .023). CONCLUSIONS: Differences in specialty training and experience strongly influence endodontic decision making. Endodontists showed the most consistent agreement among the groups.