Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

Objective

This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments.

Material and Methods

One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mm (50SB) or 250 mm (250SB) Al₂O₃. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey''s test (α=0.05).

Results

On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05), while no significant difference was found among OP, S, and TL groups. On 250SB surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05). No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05).

Conclusion

Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi.     

The restoration of permanent immature anterior teeth,root filled using MTA: A review

Objectives

Immature anterior teeth are at high risk of root fracture following root canal treatment. The literature was explored to determine the current status for post-endodontic restorative management of these teeth.

Data and sources

The authors explored multiple search engine databases to November 2008. Experiments included in the review involved simulated human or animal immature teeth with mineral trioxide aggregate as an apical plug. The experiments were designed to assess and compare the fracture strength of teeth restored with various materials. Studies that did not fulfil inclusion criteria were omitted from the review.

Study selection

Four in vitro studies fulfilled selection criteria and were systematically reviewed. All studies differed in sources of teeth, their simulated immature tooth model and mode of force application.

Clinical Implications

Current evidence, mostly from laboratory studies, suggests the use of composite resin materials placed deep into the coronal aspect of the root canal to impart superior fracture resistance. Further clinical research is needed to assess other reinforcing materials, which include a variety of post systems and luting agents.     

INFLUENCE OF POST-CURE TREATMENTS ON HARDNESS AND MARGINAL ADAPTATION OF COMPOSITE RESIN INLAY RESTORATIONS: AN IN VITRO STUDY

Objectives:

The purpose of this study was to evaluate the Vickers hardness number (VHN) and the in vitro marginal adaptation of inlay restorations of three hybrid composite resins (Filtek Z250, Opallis and Esthet-X) subjected to two post-cure treatments.

Material and Methods:

For the microhardness test, three different groups were prepared in accordance with the post-cure treatments: control group (only light cure for 40 s), autoclave group (light cure for 40 s + autoclave for 15 min at 130°C); and microwave group (light cure for 40 s + microwave for 3 min at 450 W). To assess the marginal adaptation, the composite resin was inserted incrementally into a mesial-occlusal-distal cavity brass mold and each increment light-cured for 40 s. A previous reading in micrometers was taken at the cervical wall, using a stereomicroscope magnifying glass equipped with a digital video camera and image-analysis software. Subsequently, the specimens were subjected to the post-cure treatments (autoclave and microwave) and a reading was taken again at the cervical wall. Data were compared using ANOVA for the hardness test, split-plot ANOVA for the adaptation assessment and Tukey''s test for multiple comparisons. A significance level of 5% was adopted for all analyses.

Results:

The post-cure treatments increased the hardness of conventional composites (p<0.001) and the gap values of inlay restorations (p<0.01). Filtek Z250 showed higher hardness (p<0.001) and lower gap values than Opallis and Esthet-X (p<0.05). Gap values did not exceed 90 μm for any of the experimental conditions.

Conclusion:

The post-cure treatments increased the VHN and the gap values on the cervical floor of composite resin inlays. Moreover, Filtek Z250 showed the best results, with higher hardness and lower gap values.     

排龈技术在牙体缺损修复中的应用

目的观察排龈对3MZ250复合树脂修复牙体缺损疗效的影响。方法选择31例120颗唇颊面牙颈部龋缺损牙,随机分为实验组和对照组,每组60颗,经窝洞预备后,实验组排龈线排龈后3MZ250复合树脂修复,对照组直接树脂修复,随访2年,评价修复体保存、继发龋以及边缘密合状况。结果充填后1周复查,使用排龈线组修复后悬突的发生率低于对照组,差异有显著性（P〈0．01）。充填后0．5年复查两组脱落率无明显差异;1年及2年后复查实验纽充填体的脱落率明显低于对照组（P〈0．05）。结论排龈可提高3MZ250复合树脂修复牙体缺损的修复体保存率,可以作为一项常规使用措施。     

Free thoracodorsal,perforator-scapular flap based on the angular artery (TDAP-Scap-aa): Clinical experiences and description of a novel technique for single flap reconstruction of extensive oromandibular defects

PurposeThe reconstruction of oromandibular defects can be challenging, particularly when considerable amounts of bone and soft tissues are lost. In such cases, the use of a single flap may be unsatisfactory and a concomitant free flap is needed. Here we present a chimeric, thoracodorsal perforator-scapular free flap based on the angular artery of the subscapular system (TDAP-Scap-aa) as an alternative technique for single flap reconstruction of extensive oromandibular defects.Materials and methodsThe authors studied patients who underwent reconstructions of extensive oromandibular defects with a TDAP-Scap-aa free flap. The operative technique and the clinical experiences are described. Postoperatively, surgical complications were classified with the Clavien-Dindo Classification.ResultsFive male patients (59.4 ± 8.8 years) were treated with the TDAP-Scap-aa. Average sizes for harvested hard and soft tissue components, which are both included in the flap and completely independently from each other, were 10.4 ± 1.5 cm of bone length, 2.6 ± 0.3 cm of bone height, 11.6 ± 4.8 cm of skin paddle length and 8.4 ± 1.7 cm of skin paddle width. The overall mean operation time (cut-suture) was 14.6 ± 0.9 h. The postoperative follow-up was 6 months. No complications requiring surgical treatment as well as donor site nerve damages were observed.ConclusionsIn comparison to other double free flaps, the TDAP-Scap-aa offers several advantages such as higher amounts of hard and soft tissues without prolonged operation times, and provides satisfying aesthetic outcomes and little donor site morbidity due to the preservation of muscle and nerve structures. Therefore, the TDAP-Scap-aa constitutes a clinically reliable alternative in extensive oromandibular defect reconstruction.     

Titanium dioxide and modified titanium dioxide by silver nanoparticles as an anti biofilm filler content for composite resins

Objective

The aim of this study was to evaluate the antibacterial activity of a composite resin modified by TiO₂ and TiO₂/Ag nanoparticles and their influence over different properties.

Fabrication of maxillary single complete denture in a patient with deranged mandibular occlusal plane: A case report

Construction of a single complete denture (SCD) is a challenging clinical situation especially when the opposing natural dentition is not in a normal plane of occlusion. Mal-aligned, tilted or supra-erupted teeth in the opposing arch are some of the problems that should be corrected to achieve a balanced occlusion in patients who require SCD. Achieving harmonious occlusal plane is a primary objective of any restorative procedure to facilitate natural mandibular movements and ease of mastication. Establishment of normal occlusal plane in opposite arch is pre-requisite to maintain the stability of the SCD. This clinical report describes restoration of mandibular teeth (with severe attrition and deranged occlusion) by establishing normal plane of occlusion with the help of custom made occlusal plane template (OPT) followed by construction of a complete denture in maxillary arch.