European Journal of Prosthodontics and Restorative Dentistry最新文献

Introduction: The aim of this study was to investigate the co-influence of indirect mesio- occlusal-distal (MOD) cavity geometry and inlay restoration bonding on quasi-static fracture load of the restored tooth.

Methods: Forty-eight intact human molar teeth were selected and prepared for standardized edge-shaped or round-shaped MOD cavities. The resin composite (Cerasmart, GC) inlays were bonded with the state-of-the-art inlay bonding protocol or with intentionally deteriorated bonding using n-hexane-wax solution for preconditioning. Restored teeth were loaded along the long axis of the tooth. Ultimate fracture load was recorded, and the type of fracture was visually determined and classified. Statistical analysis of load values was performed by Kruskal-Wallis test.

Results: Round-shaped cavity design with bonded restoration presented the highest fracture load (1658N). Bonding had significant influence on the fracture load of roundshaped cavity design (p=0.0003), whereas cavity design had no influence when the bonding was deteriorated (p=0.8075). In the case of deteriorated bonding, either the inlay or tooth fractured separately whereas in the bonded inlays fractures were commonly found both in the tooth and inlay.

Conclusions: According to this study, bonded inlay restoration increased fracture resistance, while cavity design had no statistical difference on fracture resistance of the restored tooth.

This study aims to investigate the effects of laser-activated irrigation on root canal dentin using different laser wavelengths. Sixty-six roots were prepared and split longitudinally. First, lasers with different power settings were tested on 34 samples, pre-etched with phosphoric acid, or remaining with a smear-layer to determine the test parameters. Selected parameters were then applied on thirty roots (9 groups) covered with smear layer: 1. Smear-layer removed; 2. Smear-layer untouched; 3. Conventional needle irrigation with NaOCl and EDTA; 4. ER:YAG laser; 5. 9.3 μm CO₂ laser; 6-9. Diode lasers. All lasers were applied in ultra-pure water as an irrigant. Root halves were examined by scanning electron microscope to analyze the intracanal dentin micromorphology on 9 consequent photos per specimen @ a magnification of 1000X. The results showed that conventional needle irrigation was effective in removing the smear-layer from coronal and middle root parts, while laser-activated irrigation had two main mechanisms: cleaning and opening of the dentinal tubules by removing the smear layer (Er:YAG laser) and melting of dentin (CO₂ and diode lasers) in all root parts. The study concluded that laseractivated irrigation with different wavelengths impacted the smear layer and root canal dentin differently through pure physical/mechanical effects.

Introduction: This systematic review examined the effect of neutralizing agents on bond strength after irrigation with sodium hypochlorite and their existing protocols in literature.

Methods: This present study adhered to the PRISMA guidelines and was registered at PROSPERO. Five electronic databases were searched (sept-2020/jan-2021) in English, Spanish, and Portuguese, without any restrictions on publication date. Cases reports, editorials and literature reviews were not included. The risk of bias was assessed using the Cochrane Collaboration tool. From the initial 7,147 studies, 2,745 were removed as duplicates and 4,382 were excluded after a title/abstract screen.

Results: Seventeen in vitro studies were included. The results showed that the higher the concentration of sodium hypochlorite, the lower the bond strength at dentine/restoration interface (p⟨0.01). Among the studies, sodium ascorbate was the most widely used neutralizer and showed the most significant results in increasing bond strength (p⟨0.01). The bond strength values were found to increase with longer application time of the neutralizing substances (p⟨0.01).

Conclusions: The use of sodium ascorbate as a neutralizing agent can reverse the negative effects of the sodium hypochlorite and improve the bond strength between dentine and resin cement, however, it isn't possible to determine the best protocol for use.

Aim: To evaluate the microtensile bond strength of self-etching adhesive systems in dentin treated with 2% chlorhexidine digluconate (CHX).

Materials and methods: The occlusal surfaces of 20 human molars were removed and divided into eight groups: 1A, Clearfil SE adhesive (SE) with self-etching technique (TS); 1B, SE with TS and previous application of CHX; 2A, Scotchbond Universal (SBU) adhesive with TS; 2B, SBU adhesive with TS and previous application of CHX; 1C, SE with total-etching technique (TT); 1D, SE with TT and previous application of CHX; 2C, SBU with TT; 2D SBU with TT and previous application of CHX. Composite resin (5mm) was applied on the hybridized surface. Samples were subjected to microtensile test and evaluated on Scanning Electron Microscope (SEM) and with energy-dispersive X-ray (EDX).

Results: Low values of bond strength were observed in groups 1A (39,77±11,56) and 2A (40,84±12,49) comparing with 1B (22,86±5,18) and 2B (27,02±5,58). TS group presented adhesive type remover fracture while TT groups presented cohesive at the top of hybrid layer. EDX revealed the presence of CHX crystals for TS, which was not found in the TT.

Conclusion: The previous application of chlorhexidine on dentin decreased the bond strength of adhesive systems on self-etching technique.

Introduction: The degree of conversion (DC) of resin cements can be affected by ceramics, and by the type of resin cement. The purpose was to evaluate the influence of thickness and translucencies of lithium disilicate ceramic on the DC of resin cements: two light-cure (Variolink LC; NX3 LC) and one dual-cure (NX3 Dual).

Methods: IPS e.max Press ceramic (A2) discs were prepared in 4 thicknesses (0.3, 0.5, 1.0, and 1.5 mm) and in 3 translucencies: HT (high translucency), LT (low translucency), and MO (medium opacity). Subsequently, 234 samples of resin cement (5 x 1 mm) were light-cured through those ceramic discs. The DC was assessed by Fourier Transform Infrared Spectroscopy (FTIR).

Results: Ceramic thicknesses decreased DC of NX3 Dual through HT-1.0 and HT 1.5 (p=0.005). Between translucencies, only MO-0.3 affected Variolink LC DC (p=0.018). There was difference among light- and dual-cured resin cements (p=0.001).

Conclusion: Increasing thickness and opacity lead to a decrease in the DC of all resin cements, with a significantly lower DC value in NX3 Dual (HT-1.0; HT-1.5), and in Variolink LC (MO- 0.3). Light- and dual-cured resin cements were different among each other. NX3 Dual achieved a significantly lower value than its counterpart NX3 LC.

Introduction: The association of the periodontium with the fixed prosthesis is the basis of prosthetic rehabilitation. This prospective case series aimed to evaluate periodontal health through the relation between periodontal/peri-implant disease progression and the use of fixed partial dentures (FPDs).

Methods: Probing depth (PD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI) on either teeth or implants were evaluated at up to 25-year follow-up and compared with the baseline. Statistical analysis was performed using the Kaplan-Meier test (p⟨0.05).

Results: The prospective evaluation showed that the patients maintained adequate periodontal health. Failure (severe periodontal stages) occurred in 12.5% of patients. The survival rate for 107 teeth/implants was 80.48%. The comparisons for clinical parameters revealed no statistically significant difference (p⟩ 0.05). At T1, the measurements for anterior and posterior regions, respectively, were PD =2.7mm and 3.1mm; CAL= 3.3mm and 3.6mm; GI=0.5 (both regions); and PI=0.79 and 0.62. Periodontal/peri-implant disease progression did not relate to the use of prostheses.

Conclusions: Patients with more frequent follow-up appointments and lower GI and PI showed periodontal health for longer periods. Patients with different oral hygiene levels present different periodontal disease progression. Periodic hygiene control and motivation are vital factors for extensive oral rehabilitation success.

Molar-incisor hypomineralisation (MIH) is a qualitative defect of the enamel structure. Indirect restorations may represent the most suitable therapeutic solutions for patients presenting MIH with tooth restorative procedures. This systematic review aims to determine the feasibility of indirect restorations.

Materials and methods: A systematic review has been performed and is reported following the PRISMA guidelines. It was performed on three databases (PubMed, Science Direct, and Google Scholar). Ten articles were included.

Results: Only two articles reported the use of CAD/CAM technologies, whereas the other eight preferred conventional registration and handmade stratification for ceramics. All indirect bonded restorations made of composite resins or ceramics had significant success rates. A temporary material was placed in most of the articles. There was no clear consensus for tissue conditioning before bonding. Depending on the authors and the articles, the follow-up period extended from 2 months to 6 years.

Conclusions: The survival rate and the non-invasive procedures of indirect restorations are two main arguments that can help dental practitioners in daily practice. Development of CAD/ CAM technologies adds new perspectives in the registration, the design and production. However, more clinical trials are needed to confirm the conclusions.

Introduction: This in-vitro study investigated limitations of intra-oral scanners (IOS) in capturing palatal defects at decreased mouth openings. The trueness and precision of composite 3D-printed models from Cone-Beam Computed Tomography (CBCT) and IOS were measured.

Methods: A partially dentate palatal defect model was scanned with IOS (3M™TrueDefinition) at various simulated mouth openings. Five silicone impressions were poured in gypsum. Scans were taken using 3M™TrueDefinition; Planmeca Planscan®, n=5 each. Model was scanned on two CBCT (PlanmecaProFace®; Accuitomo170®CBCT, n=5 each). Geomagic®Control2014™ was used to create composite-models merging CBCT with IOS. Thirty composite-models were 3D-printed. Trueness and precision were measured. Pearson Correlation Coefficients measured correlation between mouth opening and data capture. Data analysed using Kruskal-Wallis, Wilcoxon rank-sum, and ANOVA. Statistical significance inferred when p⟨0.05.

Results: Mouth openings ⟨20mm, IOS didn't capture information of soft tissue. Increased mouth opening positively correlated with increased data capture(r=0.93, p=0.001). AccuitomoCBCT and TrueDefinition IOS composite-models had the highest (trueness) and [precision](median (IQR) 0.172 mm(0.062-0.426)); [mean [SD] 0.080 mm [0.008]]. Casts had the lowest results (median (IQR) 0.289 mm(0.119-1.565));[mean [SD] 0.338 mm [0.089]](p⟨0.001).

Conclusion: Mouth opening ⟨20mm resulted in insufficient data capture by IOS for clinical applications. Composite digital models showed promising trueness and precision results.

Aim: Evaluate the influence of occlusal loading on the stress distribution of endodontically treated teeth after root canal preparation with different file's sizes and tapers by means of finite element analysis.

Methodology: Seven three-dimensional models of a single-rooted, single-canal lower second premolar were established, one healthy control and six endodontically treated and restored models. The shape of root canal preparations followed file configurations 30/.05, 30/.09, 35/.04, 35/.06, 40/.04, and 40/.06. Von- Mises equivalent stresses were calculated by applying 30 N, 90 N and 270 N loads to the buccal cusp tip, each one at 90º, 45º and 20º angles from the occlusal plane simulating occlusion, dental interference and laterality, respectively.

Results: 45º loading was more prone to formation of higher stress values. The simulation of occlusion and laterality resulted in maximum stress areas located at the inner side of the root curvature, while under occlusal interference they were on the lingual surface over the tooth's long axis.

Conclusions: The angulation of occlusal loading and magnitude were determinants for stress distribution on dental structure. Both variations of size and taper were not determinants for the increase in the maximum stress areas.

Background: There is limited evidence available regarding patient satisfaction and quality of life assessment in patients with intraoral maxillofacial defects managed with maxillofacial prostheses.

Objectives: This systematic review aims to understand the impact of intraoral implant prostheses in improving the quality of life in patients with intraoral maxillofacial defects/abnormalities.

Methods: A comprehensive search was performed of nine electronic databases from January 1970 to August 2022. Hand searching of the reference lists of the included papers and of relevant journal publications between 2012 and 2022 was also undertaken. Key information was extracted from included studies alongside quality and risk of bias assessments.

Results: The systematic review encompassed a total of seven studies, comprising five retrospective and two prospective investigations, with one of the prospective studies being a randomised clinical trial. The evaluation of the risk of bias and quality assessment revealed heterogeneity in the results, preventing meaningful comparisons among the included studies.

Conclusion: Within the limitation of the systematic review, there is limited evidence to suggest that implant prostheses improve the quality of life in patients with intraoral maxillofacial defects or abnormalities.