Is laser conditioning a valid alternative to conventional etching for aesthetic brackets?

AIM: ER:Yag lasers have been described as a more conservative alternative to conventional acid-etching enamel conditioning technique, when bonding conventional metallic orthodontic brackets. Since the use of aesthetic orthodontic brackets is constantly increasing, the purpose of the present report has been to test laser conditioning with different aesthetic brackets. MATERIALS AND METHODS: Study Design: Five different aesthetic brackets (microfilled copolymer, glass fiber, sapphire, polyoxymethylene and sintered ceramic) were tested for shear bond strength and Adhesive Remnant Index scores using two different enamel conditioning techniques (acid etching and ER:Yag laser application). Two hundred bovine incisors were extracted, cleaned and embedded in resin. Specimens were then divided into 10 groups with random tables. Half of the specimens were conditioned with conventional orthophosphoric acid gel, the other half with ER:Yag laser. Different aesthetic brackets (microfilled copolymer, glass fiber, sapphire, polyoxymethylene and sintered ceramic) were then bonded to the teeth. Subsequently all groups were tested in shear mode with a Universal Testing Machine. Shear bond strength values and adhesive remnant index scores were recorded. Statistical analysis was performed. RESULTS: When considering conventional acid etching technique, sapphire, polyoxymethylene and sintered ceramic brackets exhibited the highest SBS values. Lowest values were reported for microfilled copolymer and glass fiber appliances. A significant decrease in SBS values after laser conditioning was reported for sapphire, polyoxymethylene and sintered ceramic brackets, whereas no significant difference was reported for microfilled copolymer and glass fiber brackets. Significant differences in ARI scores were also reported. CONCLUSIONS: Laser etching can significantly reduce bonding efficacy of sapphire, polyoxymethylene and sintered ceramic brackets.

Performance of the LHCb RICH detector at the LHC.

The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2-100 GeV/c. The operation and control, software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types (π, K, p) is achieved.

Oral signs in the diagnosis of celiac disease: review of the literature.

This study explores the possibility that the celiac disease (CD) may be correlated with the insurgence of some oral signs, as based on a systematic review of the literature. Should this correlation be proven, any dentistry's screening would then be important to diagnose early celiac sprue pathogenesis. A literature survey was accomplished by using the Medline database (Entrez PubMed). The survey, which covered the period from the year 1972 to 2009, provided 382 published articles. Of these, 29 articles were selected according to inclusionary/exclusionary criteria, and consequently qualified for the final review analysis. Manual searching through the reference lists of the selected articles allowed the obtainment of others 17 articles. Findings gathered through this literature's review corroborate the significance of a causal relationship between some oral signs and CD. There are enough evidence making the correlation between CD and oral defects scientifically sustainable. This recognition should lead dentists to play more significant roles in screening for CD, as otherwise, if not properly diagnosed and not treated with a gluten-free diet, may eventually cause some malignancies.

Early interception of skeletal-dental factors predisposing to temporomandibular disorders during child development.

Temporomandibular disorders (TMD) comprise a heterogoneous group of pathologies or dysfunctions of the temporomandibular joints and their related neuromuscular systems. The multifactoral etiology of these disorders raises serious diagnostic and therapeutic problems. A modern approach demands close collaboration between a number of specialists in order to create the best possible treatment plan. The progressive nature of certain forms of TMD, combined with the major advantages deriving from early treatment, encourage the dental surgeon to carry out early interception of all those dental and/or skeletal anomalies which may determine the dysharmonic function and development of the facial mass, even though such anomalies may not represent the sole causes of the various forms of TMD. The general practitioner, and to an even greater extent the pediatrician, may therefore play a role of primary importance as those medical influences capable of early detection of TMD risk situations.

Health evaluation of free-ranging rockhopper penguins (Eudyptes chrysocomes) in Argentina.

As part of annual colony counts in Santa Cruz Province, Argentina, a health survey of rockhopper penguins (Eudyptes chrysocomes) was conducted in 1994. Forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. All birds appeared to be in good condition. No ecto- or endoparasites were found. Hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. Antibodies against Chlamydia sp., avian adenovirus, avian encephalomyelitis virus, infectious bronchitis virus, avian reovirus, and paramyxovirus-1, -2, and -3 were found. Mean plasma chemistry and mineral values differed between individuals testing positive and negative on serologic tests. There was no serologic evidence of exposure to avian influenza virus, duck viral enteritis, infectious bursal disease, infectious laryngotracheitis, Aspergillus sp., or Salmonella pullorum. Trace amounts of endrin were found in the plasma of one bird, but all other chlorinated pesticide and polychlorinated biphenyl levels were below detectable limits.

Adaptations of masticatory muscles to a hyperpropulsive appliance in the rat.

The plasticity of masticatory muscles was studied by comparing rats that were wearing a protrusive appliance and were kept on a liquid diet with two control groups: (1) pair-fed rats and (2) rats that had free access to ordinary pelleted food. The animals were 45 days old at the beginning of the experiment and were studied for a period of 20 days. Three jaw muscles with different functions were examined: masseter, temporalis, and digastric. Muscle fiber composition was determined (1) by fiber counting after staining with four monoclonal antibodies, which were able to recognize the four major myosin heavy chain (MHC) isoforms and therefore four fiber types (I, IIA, IIX, IIB) and (2) by electrophoresis on 6% polyacrylamide gels. The comparison between free-diet rats and pair-fed rats showed that the change from a hard pelleted diet to a liquid diet caused a shift in fiber type and MHC distribution, characterized by an increase of IIB MHC in temporalis and digastric muscles but not in the masseter muscle. The comparison between pair-fed rats and rats wearing appliances showed on the contrary a decrease in IIB MHC and an increase in IIA and IIX MHC. The results support the conclusions that (1) rat jaw muscles can quickly adapt to functional demand changing their fiber type composition, (2) the changes appear restricted inside the fast fiber population, and (3) fiber-type changes caused by dietary variation are not less than those caused by orthodontic intervention and must be taken into account to assess the effect of the appliance correctly.

[Dynamic changes in nasal resistance and cephalometric parameters in mouth breathing children two years after adenotonsillectomy]. / Modificazioni dinamiche delle resistenze nasali e dei parametri cefalometrici in bambini respiratori orali rilievi a due anni dall'intervento di adenotonsillectomia.

The Authors show the results of a research after 2 years from adenotonsillectomy or adenoidectomy. The comparison between the results after 6 and 24 months shows there are no differences among these results.

[Facial asymmetry: orthodontic resolution of a clinical case]. / Asimmetrie facciali: risoluzione ortodontica di un caso clinico.

In this study the authors show the importance of an early diagnosis and an interceptive approach in the presence of facial asymmetries and present a case of successful orthodontic treatment in a 20 year old patient.

[Oro-facial-digital syndrome type II: clinical and cephalometric study of a case]. / La sindrome oro-deigito-facciale tipo II: studio clinico e cefalometrico di un caso.

The Authors report a case of Oral-Facial-Digital syndrome type II (Mohr syndrome); three cephalometric tracings and a clinical study were carried out, in order to evaluate the oro-facial abnormalities. A complete cephalometric study has never been performed in this syndrome before.

[The handicapped and dental therapy. Personal experience]. / Handicap e terapia odontostomatologica. Contributo personale.

Problems binded with dental treatment of handicapped patients and analysis of data obtained in ten years of experiences have been pointed out. The preventive role of oral hygiene, the role of narcosis in treatments and structural lacks come out from this analysis.

[Histological evaluation of tooth movement using immunocytochemical research]. / Valutazione istologica degli spostamenti dentari mediante indagine immunocitochimica.

A new immunocytochemical methodology has been applied to value the proliferation in the periodontal tissue following experimental tooth movement. Orthodontic tooth movement has been obtained in Guinea pigs by a coil sporing, and a proliferation marker administrated "in vivo"; the proliferation marker used is Bromodeoxyuridine, a thimidine analogue which is taken up by DNA synthesizing nuclei, and afterwards intensified by two monoclonal antibodies, where the second is FITC coniugated. Instead of some technical difficulties, the results are encouraging for further development.

[Loss of upper central incisor: an orthodontic solution to a clinical case]. / Perdita di un incisivo centrale superiore: soluzione ortodontica di un caso clinico.

The authors show an orthodontic closing spaces solution in twelve year old subject, after loss of central maxillary incisor with an aesthetic and functional result satisfactory.

[Clinico-histological evaluation of surgical orthodontic treatment for fused teeth]. / Valutazione clinico-istologica del trattamento chirurgico-ortodontico dei denti fusi.

Seeking an evaluation pattern for periodontal wounds following the surgical section of two fused teeth healing, the authors caused in an animal a similar lesion. After that, they valued the undergoing to pressure or traction periodontal re-organizing and the histological-clinical data showed a tissues favourable repair.

[Oral hygiene motivation in orthodontic patients]. / Andamento dell'igiene orale nel paziente ortodontico.

The task of the present study has been to verify experimentally if prolonged motivation may produce better oral hygienic conditions in orthodontic patients. Applying oral hygienic index modified, gingival index and saliva lactobacilli's concentration count, the A.A. obtained encouraging data evaluating the motivated subjects situation versus control group.