Angela Militi

Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm2) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system.

In vitro evaluation of resistance to sliding in self- ligating and conventional bracket systems during dental alignment

Objective To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36℃ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. Results The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Conclusions Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when low-stiffness alignment wires are used.

Low-dose protocol of the spiral CT in orthodontics: comparative evaluation of entrance skin dose with traditional X-ray techniques

BackgroundThe aim of this study was to evaluate the amount of radiation doses absorbed by soft tissues (entrance skin dose) with a low-dose spiral computed tomography (CT) protocol compared to conventional X-ray techniques commonly used in orthodontics.MethodsThe amount of skin dose has been evaluated using a tissue-equivalent head-neck radiotherapy humanoid phantom with thermoluminescent dosimeters placed at the level of eye lens, parotid glands, and thyroid glands. CT images have been taken using a Sensation 16 Siemens CT scan and a low-dose protocol (15 mAs, 1 pitch, 2.5 mGy (CTDIvol), 80 kV, 1-mm slice thickness).ResultsThe difference in image quality between traditional X-ray techniques and low-dose spiral CT was statistically significant (P < 0.05). The difference in mean absorbed dose instead was not statistically significant.ConclusionsOur protocol allows a more accurate orthodontic diagnosis without an increase of radiological risk for the patients in comparison to traditional X-ray techniques.

Anti-inflammatory effect of ATB-352, a H2S −releasing ketoprofen derivative, on lipopolysaccharide-induced periodontitis in rats

&NA; Periodontal disease is the most common cause of tooth loss in humans, is an inflammatory disease initiated by oral microbial biofilm. Given the involvement of the inflammatory pathway in this type of pathology, the main pharmacological strategy for the treatment of periodontitis, is the inhibition of the inflammatory process in order to prevent tissue destruction and bone resorption, a condition associated with a painful state. To do this, the best class of drugs are Non‐steroidal anti‐inflammatory drugs (NSAIDs), however, the presence of side effects, especially at the gastrointestinal tract, limits their use for long‐term therapy. Recently, some evidence shows that derivatives of NSAIDs capable of releasing hydrogen sulphide exhibit lower collateral effects, particularly at the gastric level. In fact, H2S is an endogenous gaseous mediator with a cytoprotective role at the gastric level. In this study, we have compared the protective effects of ketoprofen with ATB‐352, a hydrogen sulfide‐releasing derivative of ketoprofen, in an experimental model of periodontitis in rat. Periodontitis was induced by a single intragingival injection of 1 &mgr;l LPS (10 &mgr;g/&mgr;l), Our results show that 14 h after intragingival injection of LPS, there was a high tissue damage associated with bone resorption, and in gingivomucosal tissues there was a significant expression of NF‐kb p65 and pro‐inflammatory cytokine as well as a higher expression of COX‐2 and iNOS, activation of the apoptotic process, and also increased levels of NGF expression, often associated with a higher nociceptive perception. Treatment with ATB‐352 at the dose of 20mg\kg, was able to reduce the inflammatory process associated with intragingival LPS injection and also had a positive effect on bone resorption and tissue damage. Graphical abstract Figure. No caption available.

No Compliance Correction of Class II Malocclusion in Growing Patients Whit HERBST Appliance: A Case Report

Background: Class II malocclusion is the most common sagittal skeletal discrepancy, with a prevalent skeletal pattern of mandibular retrusion. The correction of mandibular retrusion with functional removable appliance needs a good patient’s compliance; for this reason, some clinicians prefer to use no compliance apparatus. Objective: Objective of the present therapy note is to demonstrate that the use of no compliance apparatus can provide a good correction of skeletal class II malocclusion. Methods: In the present study, authors report a therapy note referred to a 10 years old patient, woman, affected by Class II, with mandibular retrusion and deep bite, treated in 2013 at the Dep. of Orthodontics of Messina University. An orthodontic treatment has been planned with the aim of stimulating mandibular growth; an Herbst appliance with a cantilever design, bonded on first maxillary and mandibular molars, has been used. After eleven months of functional therapy a bilateral molar class I have been obtained. Results: In the therapy note proposed, authors obtained a resolution of mandibular retrusion, a correction of overjet, overbite and dental crowding in both arches, and a bilateral molar and canine class I has been achieved. Conclusion: Herbst appliance seems to be efficient in the correction of II Class Malocclusion, independently from patient’s cooperation; moreover , early correction of Class II malocclusion with functional appliances produces several clinical advantages.

Oxidative Stress Evaluation in Patients Treated with Orthodontic Self-ligating Multibracket Appliances: An Case-Control Study

Objective: Oxidative stress is a pathologic event induced by a prevalence of oxidant agents on the antioxidant ones, with a consequent alteration of oxide-reducing balance. Introduction: Freeradicals produce damages both in cellular and extra-cellular components; phospholipid membranes, proteins, mitochondrial and nuclear DNA, are the target of the oxidative stress, that can finally cause cellular death due to apoptosis. Materials & Methods: Orthodontic appliances such as brackets, wires, resins and soldering have some components that can be considered as potential allergen, carcinogenic, cytotoxic and gene mutation factors. The primary aim of this research is to evaluate oxidative stress in the saliva of patients treated with multibracket self-ligating vestibular orthodontic appliances; the secondary purpose is to investigate the influence of orthodontic multibracket therapy on oral hygiene and the consequent effect on oxidative stress. Salivary specimens has been collected in a sample of 23 patients were enrolled (12 Female, 11 Male) between 12 and 16 years of age (mean age 14.2). For each patient has been collected a salivary specimen at the following time points; before orthodontic bonding (T1), five weeks (T2) and ten weeks (T3) after orthodontic appliance bonding. Results: Samples has been analysed with a photometer due to SAT Test (Salivary Antioxidant Test). Data obtained show a mean of 2971 mEq/l of anti-oxidant agents before orthodontic treatment, and after five weeks from the bonding the mean was decreased to 2909 mEq/l, instead at ten weeks was increased to 3332 mEq/l. Repeated measures ANOVA did not reveal statistically significant differences between the time points (P = 0.1697). The study did not reveal any correlation between the level of dental hygiene and that of oxidative stress (Pearson Correlation Coefficient R = 0). Conclusion: Orthodontic treatment with multibrackets vestibular metallic appliance seems to be not able to affect oxidative stress during the first ten weeks of therapy.

Skeletal and Dental Effectiveness of Treatment of Class II Malocclusion With Headgear: A Systematic Review and Meta-analysis

Objective To evaluate the skeletal and dental effects of headgear treatment by systematically reviewing the best available scientific evidence. Materials and Methods A survey of articles published up to February 2017 investigating the effects of headgear in the treatment of patients with class II malocclusion was performed using 19 electronic databases. Only randomized clinical trials and prospective controlled clinical trials investigating growing patients with class II malocclusion treated with headgear were included. Two authors performed independently study selection, data extraction, and risk of bias assessment. All pooled data analyses were performed using the random‐effect model. Statistical heterogeneity was evaluated. Results In total, 6 trials were included (4 randomized clinical trials and 2 prospective controlled clinical trials), grouping data from 337 patients (170 treated patients and 167 untreated controls). The ages of the patients varied across the studies, but the majority of the trials had a sample with an age range between 8 and 9 years. The times of daily wear of the appliance varied across studies from 8 to 14 h/d. The significant mean differences in treatment effects compared with the untreated controls were −1.41° per year for SNA angle cephalometric parameter (95% confidence interval [CI]: −2.25° to −0.56°), −0.57 mm/y for anterior maxillary displacement (95% CI: −0.75 to −0.40 mm), −1.42° per year for ANB angle cephalometric parameter (95% CI: −2.12° to −0.72°), and −1.31 mm/y for the overjet cephalometric parameter (95% CI: −2.34 to −0.29 mm). Conclusion Headgear treatment is effective in restricting sagittal maxillary growth and reducing the overjet in the short term.

Effects of rapid vs slow maxillary expansion on nasal cavity dimensions in growing subjects: A methodological and reproducibility study

AIM To evaluate the methodological feasibility of a RCT comparing skeletal changes of nasal cavity size obtained with RME and SME, assessed via CBCT. MATERIALS AND METHODS Twenty Caucasian children with a mean age of 10.4 years were recruited and allocated to receive RME (10 subjects, mean age 10.4 years) or SME (10 subjects, mean age 10.5 years). INCLUSION CRITERIA constricted maxillary arch, upper and lower first molars erupted, unilateral or bilateral posterior crossbite. EXCLUSION CRITERIA age above 15 years, history of previous orthodontic treatment, periodontal disease, systemic disease affecting craniofacial growth, or craniofacial congenital syndrome. CBCT examinations were performed before treatment (T0) and 7 months after expander removal (T1). Changes of nasal width (NW), palatal width (PW) and total nasal volume (TNV) were assessed; palatal and nasal expansion was also calculated as a percentage of the increase of intermolar width IMW (PW% and NW%). RESULTS The correlation between the first and the second readings ranged from 0.991 to 0.995 for linear measurements and was of 0.915 for volumetric measurements. The method error, as described by the value of ?, was in general less than 0.3 mm for linear measurements and 0.372 cm³ for volumetric measurements. All linear transverse skeletal and dental measurements and the nasal volume increased with both RME and SME protocols. CONCLUSION The reported methodology can be reasonably used to investigate the transverse dimension of nasal cavity. The PW% and NW% parameters more accurately described the efficacy of the two expansion protocols as compared to their corresponding absolute measurement (PW and NW).

An immunohistochemical study of the human periodontal ligament during sperimental orthodontic movement

Orthodontic tooth movement is characterized by remodeling changes in dental and paradental tissues, including dental pulp, periodontal ligament (PDL), alveolar bone, and gingiva. These tissues, when exposed to varying degrees of magnitude, frequency, and duration of mechanical loading, express macroscopic and microscopic changes. The different modification of periodontal ligament during load deformation can be monitored by analysis of the expression of different collagen types, fibronectin and vascular endothelial growth factor. The aim of this study was to evalue PDL collagen types I and IV, fibronectin and vascular endothelial growth factor (VEGF) modification induced by application of a precalibrated and constant orthodontic strength at different stages of treatment. For the study we utilized a coilspring NiTi 50 gr. and in vivo samples of 20 maxillaries and mandibular premolars of patients aged from 13 to 18 years subject to orthodontic treatment. These teeth was extracted at 1, 7, 14, 21 and 28 days from application of force respectively. The extraction of the PDL was effectuated scarifying the radicular surface on the pressure and tension side. The results were compared with periodontal ligament samples of the normal homologous teeth (control). The periodontal ligament samples were fixed in 3% paraformaldehyde in a 0,2M phosphate buffer at pH 7,4. The following primary antibodies were used: anti collagen I, anti collagen IV, anti fibronectin and mouse monoclonal anti-VEGF. Section were then observed and photographed using Zeiss LSM 510 confocal microscope. Were analyzed fluorescence intensity and compared with the control side. The signal of type I collagen is negative in tension and pressure side after 1 day, showed an increased respect to control, in the tension and pressure side, until 7, 14 and 21 days. After this stage in both sides maintained the same values of the control. The immunofluorescence of type IV collagen is negative, in both sides, after 1 and 7 days. At 14, 21 and 28 days from treatment, increased gradually in pressure side and manteined the same values of the control in tension side. The observation of fibronectin showed strongly immunofluorescence at all stages of treatment. After 1, 7 and 14 days the immunofluorescence of VEGF is negative in pressure side, and positive in tension side. In the last observation periods at 21 and 28 days, VEGF signal showing, in both sides, significant increase when compared with the control group. These findings suggest that: the increase of collagen type I and fibronectin could indicate that the solicitation by orthodontic force could determinate an increase of metabolic activity in the periodontal ligament. The rapid modification after the start of tooth movement, suggest that VEGF may be involved in the early stages of periodontal remodeling during orthodontic tooth movement, when occur rapid changes in local blood circulation. The initial decrease of collagen type IV, indicate a loss of vascular component in the early stages of movement infact this protein is localized in perivessel zones.