Fluorescence intensities of composite resins on photo images

Odontology - Recording fluorescence using flash photography, may help reduce time of capture and apply effectively in clinical practice. To test methods for visualizing composite resins...     

Intramedullary nailing of humeral diaphyseal fractures. Is distal locking really necessary?

Purpose:

Distal interlocking is regarded as an inherent part of the antegrade humeral nailing technique, but it exposes both the patient and surgeon to radiation, is time consuming, and has a potential risk of damaging neurovascular structures. We have presented our technique of diaphyseal humeral nailing without any distal interlocking in this paper.

Materials and Methods:

We have presented a series of 64 consecutive patients (33 male and 31 female, mean age: 41.5 years) with humeral shaft fractures treated with antegrade rigid intramedullary nailing without distal interlocking following a strict intra and postoperative protocol. According to the AO classification, there were 36 type A fractures, 22 type B, and 6 type C. Nails were inserted unreamed or by using limited proximal reaming and they were fitted as snuggly as possible into the medullary canal. After impaction of the nail into the fossa, we carefully tested rotational stability of fixation by checking any potential external rotation when the arm was slightly turned externally and left to the gravity forces. We were ready to add distal screws, but that was not required in these cases. Follow-up assessment included fracture union, complications and failures, and the final clinical outcome at minimum 2-year follow-up using the parameters of the constant score.

Results:

All fractures, except two, united between the 4^th and 5^th postoperative month. In one case, nail was exchanged with plate, and, in another, a larger nail was used at a second surgery. Shoulder function according to constant score, at a minimum of 2-year follow-up, was excellent or very good in 93.7% of the patients.

Conclusions:

Provided that some technical issues are followed, the method reduces intraoperative time and radiation exposure and avoids potential damage to neurovascular structures.     

Biomechanical evaluation of plating techniques for fixing mandibular angle fractures: the introduction of a new 3D plate approach

Purpose

The aim of this study was to comparatively evaluate the use of a three-dimensional (3D) square-shaped plate for the treatment of mandibular angle fractures.

Materials and methods

Synthetic mandible replicas were used to evaluate the effectiveness of the 3D square plate along with three other mandibular angle plating techniques. The plating techniques consisted of: (1) a 3D miniplate (2?×?2 holes, square, 2 mm); (2) a 3D miniplate (6?×?2 holes, curved, 2 mm); (3) two miniplates (four holes, straight, 2 mm and 1.6 mm); and (4) one single miniplate (four holes, straight, 2 mm). Each group was subjected to incisal and homolateral molar region loading by a tensile materials testing machine (Monsanto Tensometer 20). Load stiffness values and peak measurements of the fracture gap distraction at the superior aspect of the mandible were measured. The mean values (±standard deviation) were derived and compared using one-way analysis of variance, with statistical significance set at p?<?0.05.

Results

For homolateral molar loading, statistically significant differences existed within groups (p?<?0.05). For incisal edge loading, no statistically significant differences were found for stiffness among the fixation methods tested. Gap distraction at the superior aspect of the mandible was limited for three of the groups tested.

Conclusion

Under the conditions tested, the 3D square plate system provided the most favorable mechanical behavior.     

Marginal integrity of pit and fissure sealants. Qualitative and quantitative evaluation of the marginal adaptation before and after in vitro thermal and mechanical stressing

This research quantitatively evaluated the marginal adaptation of pit and fissure sealants. The occlusal surfaces of 48 intact, caries-free human molars were cleaned with an air-abrasion unit. The teeth were then randomly divided into eight groups of six teeth each according to the type of enamel conditioning, sealant material applied and curing unit used. After applying either 40% phosphoric acid gel (K-etch, Kuraray Co) or a self-etching primer adhesive system (Clearfil SE Bond, Kuraray Co), sealant materials of two viscosities were applied (Teethmate F-1 and Protect-Liner-F, Kuraray Co) and cured with halogen (Optilux 500, Demetron) or plasma arc (Apollo-95E, Dental & Medical Diagnostic Systems, Ltd) curing units. The marginal adaptation of the pit and fissure sealant restorations was evaluated by using a computer-assisted quantitative margin analysis in a scanning electron microscope (SEM) on epoxy replicas before and after thermal and mechanical stressing of the teeth. The results were statistically analyzed with one-way analysis of variance (ANOVA) at a confidence level of 95% (p=0.05). A post-hoc Tukey HSD-test was used for multiple pairwise comparisons between groups. The null hypothesis was that there was no statistically significant difference between the groups that were tested in this study. The statistically significant differences between groups were more pronounced after loading. In most cases, the self-etching adhesive system (SE Bond) proved as effective as phosphoric acid etching (K-etch). The low viscosity sealant material (Teethmate F-1), in most cases, exhibited better marginal adaptation than the high viscosity material (Protect-Liner F). The high viscosity material performed equally well only when used in combination with the self-etching primer adhesive system as an intermediate layer. The halogen curing unit (Optilux 500) led to better marginal adaptation than the plasma arc curing unit (Apollo 95E), especially after thermal and mechanical stressing.     

Antibiotic Prophylaxis in Primary Hip and Knee Arthroplasty : Comparison Between Cefuroxime and Two Specific Antistaphylococcal Agents

This is a prospective randomized study comparing cefuroxime to 2 antistaphylococal agents (fusidic acid and vancomycin), for prophylaxis in total hip arthroplasty (THA) and total knee arthroplasty (TKA) in an institute, where methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) prevalence exceeds 25% of orthopedic infections. There were 3 patient groups. Group A included the patients who received cefuroxime, group B those who received fusidic acid, and group C those who received vancomycin. Patients were evaluated for the presence of superficial and/or deep infection at the surgical site. Statistical analysis did not reveal any substantial difference between the 3 groups. We do not recommend the use of specific antistaphylococcal agents for prophylactic use in primary THA and TKA, even in institution where MRSA and MRSE exceed 25% of orthopedic infections.     

Graft-supplemented, augmented external fixation in the treatment of intra-articular distal radial fractures

This article compares the functional and radiographic outcomes of intraarticular distal radial fractures treated with augmented external fixation in which autologous cancellous bone grafting or Norian SRS (Norian Corp, Cupertino, Calif) was used for filling the metaphyseal void. Thirty non-randomized patients, 15 in each group, with AO type C distal radius fractures (20 men and 10 women; average age: 48 years) were operatively treated between 1998-2000 and retrospectively evaluated. Radial inclination, radial length, volar tilt, and Modified Mayo Wrist Score were assessed at the most recent follow-up evaluation (average: 33.3 months). Overall, 12 (80%) patients in the Norian group had an excellent or good result, 2 had fair, and 1 had poor. In the autologous iliac bone graft group, the results were excellent or good in 11 (73.3%) patients, fair in 1, and poor in 2. No statistical difference between the two types of grafting was noted. Norian SRS is equally effective to cancellous bone as supplementary graft in comminuted distal radial fractures treated by external and Kirschner-wire fixation.     

In silico studies reveal the mechanisms behind the antioxidant and anti-inflammatory activities of hydroxytyrosol

Hydroxytyrosol is one of the most important phytochemical constituents of olive oil and possesses a very interesting pharmacological profile ranging from antioxidant, antimicrobial, and anti-inflammatory to low density lipoproteins oxidation inhibition. The present study aims to shed light on the mechanisms behind the antioxidant and the anti-inflammatory activities of hydroxytyrosol. Towards the first aim, quantum mechanical calculations of several properties including bond dissociation energy, proton dissociation enthalpy, adiabatic ionization potential, proton affinity, and electron transfer enthalpy has been performed in vacuum and water environments in order to propose an antioxidant activity mechanism. Results support the hydrogen atom transfer mechanism as the most prevalent in gas phase, while in aqueous environment SPLET mechanism can explain the antioxidant mechanism of hydroxytyrosol. Towards the second aim, the potential of hydroxytyrosol to act as cyclooxygenase and lipoxygenase inhibitor against inflammation was examined through molecular docking studies. Cyclooxygenase is an enzyme, responsible for formation of prostanoids and its inhibition can provide relief from the symptoms of inflammation and pain. Lipoxygenases are a family of iron-containing enzymes involved in the metabolism of eicosanoids and their role in the regulation of pro-inflammatory responses has been well documented. Results indicate the binding mode in which hydroxytyrosol may exert its activity through lipoxygenase enzyme. Moreover, hydroxytyrosol can act as a core structure for bio-inspired inhibitors and may provide information for the design of dual cyclooxygenase/lipoxygenase inhibitors against inflammation.