Antonio López-Valverde

A new perspective in Oral health: Potential importance and actions of melatonin receptors MT1, MT2, MT3, and RZR/ROR in the oral cavity

BACKGROUND Melatonin is involved in many physiological processes in mammals, amongst others; it is implicated in sleep-wake regulation. It has antioxidant and anti-inflammatory properties. It also acts as an immunomodulator, stimulates bone metabolism and inhibits various tumours. Additionally an abnormal melatonin rhythm may contribute to depression and insomnia. The mechanisms of action of melatonin include the involvement of membrane receptors (MT1, MT2), cytosolic binding sites (MT3 and calmodulin), and nuclear receptors of the RZR/ROR family. Melatonin also has receptor-independent activity and can directly scavenge free radicals. The current review addresses the functions of melatonin in the oral cavity in relation to its receptors. METHODS An extensive search was conducted on the following scientific databases Pub Med, Science Direct, ISI Web of Knowledge and Cochrane database in order to review all pertinent literature. RESULTS Melatonin from the blood into the saliva may play an important role in suppressing oral diseases. It may have beneficial effects in periodontal disease, herpes and oral cancer, amongst others. CONCLUSIONS Melatonin contributes to protecting of oral cavity from tissue damage due to its action of different receptors. From the reviewed literature it is concluded that experimental evidence suggests that melatonin can be useful in treating several common diseases of the oral cavity. Specific studies are necessary to extend the therapeutic possibilities of melatonin to other oral diseases.

Validation of the oral health impact profile (OHIP-20sp) for Spanish edentulous patients

Objectives: The purposes of this study are to validate the indicator of Oral Health Impact Profile for edentulous patients (OHIP-20sp) in the Spanish population and to analyze the factorial construct of the prosthetic well-being. Study Design: A total of twenty-one (n=21) edentulous patients wearing mandibular implant-over dentures on Locator® (LO) and twenty (n=20) with complete dentures (CD) were retrospectively evaluated in this study. All participants were recruited consecutively and were treated in the previous academic year 2009-2010 by professors of the University of Salamanca. Reliability analyses and validity tests were performed in order to evaluate the psychometric properties of OHIP-20sp employing two different total score methods (additional and simple count). A retrospective evaluation of the impact of the prosthetic treatment was captured with an evaluative instrument derived from OHIP-20, and named POST-OHIP-13. Results: The reliability coefficient (Cronbach’s alpha = 0.91) has shown a high internal consistency. Item-total correlations coefficients ranged from 0.46 and 0.81. Five factors, named as disability, functional comfort, psychosocial impact, pain-discomfort and functional limitations were identified as principal components of the construct, explaining almost 85% of the variance. The 48% of the sample felt at least one impact in an occasional or more frequently manner (generally food packing). The global transition judgment of the prosthetic treatment using the POST-OHIP-13 was significantly higher in group LO than in the CD group. Conclusions: OHIP-20 seems to be a reliable and valid indicator to measure oral impact and satisfaction in the Spanish edentulous population. The underlying construct is comprised by 5 factors named as disability, functional comfort, psychosocial impact, pain-discomfort and functional limitations. Key words:Oral health-related quality of life, edentulous, satisfaction, validation.

Effect of adhesive application prior to bracket bonding with flowable composites

OBJECTIVE To evaluate the effect of applying an adhesive, prior to different flowable composite resins, on the shear bond strength (SBS) of orthodontic brackets to acid-etched human enamel. MATERIALS AND METHODS One hundred metal brackets were bonded to 35% phosphoric acid-etched human premolars using four flowable composites (Admira Flow, Tetric Flow, Filtek Supreme, Transbond Supreme) and a conventional orthodontic composite resin (Transbond XT). For each experimental group, half of the specimens were bonded in combination with Transbond XT adhesive. After 24 hours of storage, an SBS test was performed. Adhesive remnant index scores were determined after the failure of brackets. Two-way analysis of variance and Student-Newman-Keuls multiple comparison tests were performed at P < .05. RESULTS When using an adhesive system, the five composites performed equally. The application of adhesive had a significant effect on SBS. Without adhesive, SBS decreased in all groups, except for Transbond Supreme LV. All the test groups exhibited similar bracket failure modes. CONCLUSIONS When using an adhesive system, flowable composite resins exhibited similar SBS. Transbond Supreme was the only resin performing similarly with or without adhesive system application.

Accuracy in the legal age estimation according to the third molars mineralization among Mexicans and Columbians.

OBJECTIVES This study aims to assess the accuracy of age estimation according to two cut-off points of Demirjians developmental stages (G and H) in the wisdom teeth, using panoramic radiographs from Colombian and Mexican teenagers. STUDY DESIGN The degree of maturation of the third molars was classified according to Demirjian in 8 stages (from A to H) by a blinded trained assessor. The sensitivity, specificity and efficacy of two cut-off points (G and H) were calculated for both samples. RESULTS The orthopantomographies of 316 subjects, 171 Colombians (54.1%) and 145 Mexicans (45.9%), were analyzed. The stage H was found to be the best threshold for detecting juveniles (because the high specificity) in all the third molars assessed. The specificity was higher for lower third molars than for upper third molars, but no asymmetrical discrepancy was noted. CONCLUSIONS The stage H is the best cut-off point for detecting the adulthood when a high-specificity test is required.

Effect of topical application of melatonin on serum levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in patients with type 1 or type 2 diabetes and periodontal disease.

Background The present clinical trial study was designed to assess the effect of topical application of melatonin on serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) in patients with diabetes and periodontal disease in comparison with healthy controls. Material and Methods Serum levels of TNF-α and IL-6 were measured by enzyme-linked immunosorbent assay and CRP by nephelometry by using the proper commercial kits in 30 patients with diabetes and periodontal disease, and also in a control group of 30 healthy subjects. Periodontograms were performed using the Florida Probe®. Patients with diabetes were treated with a topical application of melatonin (1% orabase cream formula) once daily for 20 days. Healthy subjects were treated with a placebo orabase cream. Results Patients with diabetes and periodontal disease had significantly higher mean levels of serum TNF-α, IL-6 and CRP than healthy subjects (P < 0.001). Following topical melatonin application, there was a statistically significant decrease in the gingival index and pocket depth (P < 0.001) as well as a significant decrease in IL-6 and CRP serum levels (P < 0.001). Local melatonin application in patients with diabetes and periodontal disease resulted in a significant decrease in CRP and IL-6 serum levels as well as an improvement in the gingival index and pocket depth. Patients with periodontal disease had significantly higher serum CRP, IL-6 and TNF-α values by comparison with healthy subjects. Conclusions We conclude that melatonin can modulate the inflammatory action of these molecules in periodontal patients. Key words:Melatonin, periodontal disease, diabetes mellitus, interleukin-6, tumor necrosis factor-alpha, C-reactive protein, inflammatory markers.

The surgeons Halsted and Hall, cocaine and the discovery of dental anaesthesia by nerve blocking.

William Stewart Halsted is considered to be one of the most influential and innovative surgeons the USA has ever produced. His contributions to surgery are abundant, ranging from sophisticated surgical techniques in the field of breast surgery, surgery of the digestive apparatus and traumatological interventions, to the introduction of gloves in the operating theatre. Here we present Dr Halsted, together with his aide Dr Hall, as the discoverers of the technique for blocking the inferior alveolar nerve and the antero-superior dental nerve using cocaine as an anaesthetic. The anaesthetic technique, described perfectly by both surgeons in 1885, has been revolutionary in the practice of odontology since its introduction, offering dentists the possibility of performing invasive interventions to the maxillary without pain.

Comparison of Clinical and Histologic Outcomes of Zirconia Versus Titanium Implants Placed in Fresh Sockets: A 5-Month Study in Beagles

Purpose: This study evaluated the clinical and histomorphometric results of titanium (Ti) and custom-made zirconia (Zr) implants placed into fresh extraction sockets in beagles that did not receive oral hygiene attention or a softened diet during postoperative healing. Materials and Methods: The roughness of the Ti and Zr implant surfaces was assessed by confocal microscopy. In eight beagle dogs, four implants each (two Ti and two Zr) were placed in the distal sockets of the third and fourth premolars with the implant shoulder at the bone crest and subjected to submerged healing. Standardized radiographs were taken after placement and 5 months after placement (at sacrifice). Histologic and histomorphometric measurements were performed on nondecalcified histologic sections. The main outcome measures included implant survival, bone-implant contact (BIC), and bone loss on the buccal and lingual plates. Results: Topographic analysis showed significant differences between the Zr and Ti surfaces. Roughness was higher for Ti than for Zr implants, kurtosis was close to 3 for Ti, and skewness was negative for Zr. After 5 months, the mean BIC was similar for the Zr (57.0% ± 15.2%) and Ti (56.5% ± 14.4%) implants, and the most severe bone loss site was observed on the buccal wall. The risk of failure was significantly higher for the Zr (43.8%) than for the Ti (12.5%) implants. Conclusion: The implant failure rate for the Zr implants was 3.5 times higher than that of the Ti implants. This may be partially explained by the less favorable topography of the Zr implants, which had, on average, significantly lower roughness (Ra = 0.85 ± 0.04 μm), negative skewness of the surface profile (-1.56 ± 0.27), and higher kurtosis (7.88 ± 1.99).

State anxiety and depression as factors modulating and influencing postoperative pain in dental implant surgery. A prospective clinical survey

Objetives: To determine whether preoperative state anxiety and depression modulate or influence objective and subjective postoperative pain following dental implant insertion. Study Design: Prospective, clinical study with 7-day follow-up of a sample of 105 subjects who preoperatively completed the state anxiety questionnaire (STAI-E) and Beck Depression Inventory (BDI) and postoperatively, at 2 and 7 days, recorded objective pain with the Semmes-Weinstein mechanical esthesiometer (SW test) and subjective pain with the Visual Analog Scale (VAS). Results: 85.6% and 81.5% of patients, respectively, recorded no signs of state anxiety or depression. The correlation between anxiety and depression for both maxillary bones was the lower (P=0.02). The correlation between subjective and objective pain at 2 and 7 days, and the anatomic regions intervened, was statistically significant in the mandible at day 7 (P<0.01), and highly significant (P<0.001) for the other variables. The correlation between state anxiety and objective pain at day 7 was nearly statistically significant (P=0.07). Conclusions: The correlation between state anxiety and depression, and objective and subjective pain at day 7 was not statistically significant. A strong correlation was found between objective and subjective pain in the immediate postoperative period. Key words:Anxiety, depression, postoperative pain, dental implants.

The Discovery of Surgical Anesthesia Discrepancies Regarding Its Authorship

The suppression of pain during surgical interventions has been a major achievement for humankind. Chronologically, in 1842, William E. Clarke, a chemist in Rochester (NY), provided Elijah Pope with ether for the purposes of tooth extraction. In 1844, in Boston, G.Q. Colton and the dentist Horace Wells used nitrous oxide as an anesthetic for tooth extraction. On the 16th of October, 1846, the American dentist William T.G. Morton became a pioneer within the medical community with respect to anesthesia by inhalation when he used ether as an anesthetic at the Massachusetts General Hospital. In 1847, the Scot James Young Simpson began to use chloroform as an anesthetic for obstetrics in Edinburgh. These events gave rise to several disputes among their users (who are not very well-known today), who strove to claim that they had been the discoverers of surgical anesthesia, with a view to obtaining a series of patents and state sinecures. This article attempts to clarify certain discrepancies about the authorship of surgical anesthesia. The evidence suggests that surgical anesthesia first began to be applied in the field of dentistry.

MT1 Melatonin Receptor Expression in Warthin’s Tumor

We contribute the first immunohistochemical study of MT1 melatonin receptor in Warthin’s tumor and normal parotid gland. All 14 Warthin’s tumors studied showed intense cytoplasmic positivity for MT1 receptor in all cylindrical epithelial cells lining spaces and a less intense positivity in basal cells. The lymphoid component accompanying the tumor was always negative for MT1 receptor. The parotid structure surrounding the tumor showed intense cytoplasmic positivity in all cells lining excretory ducts (lobar and lobulillar), with a lesser and focal positivity in cells of the acinar component. The biological activity of MT1 receptor in epithelial cells lining parotid excretory ducts may resemble its activity in Warthin’s tumor cells. Hence, we propose Warthin’s tumor as a useful positive control in immunohistochemical studies of MT1 melatonin receptor.