Efficacy of a drug composed of herbal extracts on postoperative discomfort after surgical removal of impacted mandibular third molar: a randomized, triple-blind, controlled clinical trial.

OBJECTIVES: This study investigated and compared the effectiveness of a phytotherapeutic drug composed of herbal extracts on postsurgical discomfort after mandibular third molar surgery. MATERIALS AND METHODS: Eighty-two patients requiring the surgical removal of a mandibular third molar were randomly assigned to receive placebo (group 1), ibuprofen (group 2), and a phytotherapeutic drug (composed of baicalin, 190 mg; bromelain, 50 mg; escin, 30 mg) (group 3). Drugs were administered after tooth extraction twice a day for 5 days. The primary outcome, pain, was evaluated using a visual analogue scale at 2 h, 6 h, 12 h, 24 h, 48 h, and 7 and 10 days after surgery. The secondary outcomes were the changes in maximum mouth opening and facial contours (mm) between baseline and at 24 h, 72 h, and 7 and 10 days after surgery. RESULTS: Compared to the baseline, all treatments demonstrated an improvement in the primary and secondary outcomes. Moreover, compared to groups 1 and 2, patients in group 3 yielded a significant reduction of the postoperative pain score at 12 h (p < 0.001), 24 h (p = 0.010), and 48 h (p = 0.048) after surgery. The mean reduction of the swelling and trismus was similar between groups. CONCLUSIONS: The results of this study suggest that a postoperative administration of a phytotherapeutic drug was found to be effective in postoperative pain management after the surgical removal of impacted mandibular third molars. CLINICAL RELEVANCE: The phytotherapeutic drug composed of herbal extract determined a decrease in the severity of postoperative pain compared to ibuprofen and placebo.

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.

Three-dimensional evaluation on digital casts of maxillary palatal size and morphology in patients with functional posterior crossbite.

Background and objectives: Some authors have recently postulated the possibility of a unilateral contraction of the palate in patients with crossbite. This study aimed to investigate palatal dimension size and morphology in subjects with functional posterior crossbite and to localize location of the contraction through a 3D analysis procedure. Materials and methods: A study sample (SS) of 35 subjects (mean age 9.2 ± 0.8 years), diagnosed with functional crossbite, and a control sample (CS) of 35 subjects (mean age 9.4 ± 0.9 years) without crossbite were selected for this study. The digital models of each patient were analysed to assess palatal dimension size and symmetry by measuring linear distances between primary canines (D1) and fist molars (D2) to the median palatine plane and by performing and analysing the 3D deviation between the two specular models of the palatal vault for each patient. Results: Our findings demonstrate a significantly narrower dimension of D2 for the crossbite side than at the non-crossbite side. The 3D deviation analysis demonstrates a lower matching percentage of the palatal vault models in the SS (83.36%) compared with the CS (92.82%) and a location of that the palatal contraction is at the alveolar bone level. Conclusions: It can be assumed that there is a bilateral symmetrical contraction of the palatal vault and an asymmetric contraction of the alveolar process, but further studies are needed to corroborate this hypothesis.

The effects of a desiccant agent in the treatment of chronic periodontitis: a randomized, controlled clinical trial.

OBJECTIVE: Chemotherapeutic agents have been widely used as adjuncts for the treatment of chronic periodontitis (CP). This study investigated and compared a desiccant agent as an adjunct to scaling and root planing (SRP) versus SRP alone for the treatment of CP. MATERIALS AND METHODS: Thirty-six patients with CP were studied. Using a split-mouth design, the maxillary right and left quadrants were randomly assigned to SRP plus desiccant (Hybenx® EPIEN Medical, Inc. St. Paul, MN, USA) or SRP alone. Patients were examined on a regular basis for clinical, microbiological, and inflammatory mediator changes over a 1-year period. Clinical attachment level (CAL) was the primary outcome variable. In addition, the red complex bacteria and gingival crevicular fluid (GCF) inflammatory mediators were monitored. RESULTS: Compared to baseline, both treatments demonstrated an improvement in periodontal parameters. Compared to SRP alone, SRP plus desiccant yielded a significant improvement in probing depth (PD) (SRP: 2.23 ± 0.31 mm vs. desiccant: 3.25 ± 0.57 mm, p < 0.05), CAL (SRP: 3.16 ± 0.29 mm vs. desiccant: 4.21 ± 0.34 mm, p < 0.05 mm) and bleeding on probing (BOP) (SRP: 4.56 ± 1.5% vs. desiccant: 34.23 ± 4.2%, p < 0.001) at 12 months. Similarly, in the SRP plus desiccant group, the bacteria of the red complex were significantly reduced (p < 0.05); and the level of inflammatory mediators was significantly reduced (p < 0.003) compared to SRP alone. CONCLUSIONS: SRP plus the desiccant resulted in a greater reduction in clinical, microbial and inflammatory mediators compared to SRP alone. CLINICAL RELEVANCE: Desiccant, when combined to SRP, was demonstrated as a significant approach to control the levels of certain periodontal pathogens, inflammatory mediators in patients with CP.

The Effects of Diode Laser Therapy as an Adjunct to Scaling and Root Planing in the Treatment of Aggressive Periodontitis: A 1-Year Randomized Controlled Clinical Trial.

OBJECTIVE: The aim of this study was to investigate and compare the clinical, microbial, and inflammatory effects of a diode laser as an adjunct to scaling and root planing (SRP) versus SRP alone for the treatment of generalized aggressive periodontitis (GAgP). METHODS: Using a split-mouth design, 31 patients with GAgP were enrolled in the study. The maxillary right and left quadrants were randomly assigned to SRP+diode laser or SRP alone. Patients were examined on a regular basis for clinical, microbiological, and inflammatory mediator changes over a 1-year period. Clinical attachment level (CAL) was the primary outcome variable chosen. In addition, subgingival biofilm samples and gingival crevicular fluid (GCF) inflammatory mediators were analyzed at each follow-up session. RESULTS: Compared to baseline, both treatments demonstrated an improvement in periodontal parameters at 1 year. However, SRP+diode laser produced a significant improvement in probing depth (PD; 2.56 ± 0.44 vs. 3.36 ± 0.51 mm, p < 0.05) and CAL (3.47 ± 0.25 vs. 4.11 ± 0.26 mm, p < 0.05) values compared to SRP alone. Similarly, in the SRP+diode laser group, the bacteria of orange complex group were significantly reduced at 30 and 60 days compared to SRP alone. Moreover, SRP+diode laser determined a reduction in mean GCF level of interleukin (IL)-1ß and IL-1ß/IL-10 ratio at 15 and 30 days compared to SRP alone (p < 0.05). CONCLUSIONS: At 1 year, SRP+diode laser yielded a significant reduction in some clinical parameters, while microbial and inflammatory mediator changes were not significantly reduced compared to SRP alone.

Bone and cortical bone thickness of mandibular buccal shelf for mini-screw insertion in adults.

OBJECTIVE: To analyze the buccal bone thickness, bone depth, and cortical bone depth of the mandibular buccal shelf (MBS) to determine the most suitable sites of the MBS for mini-screw insertion. MATERIALS AND METHODS: The sample included cone-beam computed tomographic (CBCT) records of 30 adult subjects (mean age 30.9 ± 7.0 years) evaluated retrospectively. All CBCT examinations were performed with the i-CAT CBCT scanner. Each exam was converted into DICOM format and processed with OsiriX Medical Imaging software. Proper view sections of the MBS were obtained for quantitative and qualitative evaluation of bone characteristics. RESULTS: Mesial and distal second molar root scan sections showed enough buccal bone for mini-screw insertion. The evaluation of bone depth was performed at 4 and 6 mm buccally to the cementoenamel junction. The mesial root of the mandibular second molar at 4 and 6 mm showed average bone depths of 18.51 mm and 14.14 mm, respectively. The distal root of the mandibular second molar showed average bone depths of 19.91 mm and 16.5 mm, respectively. All sites showed cortical bone depth thickness greater than 2 mm. CONCLUSIONS: Specific sites of the MBS offer enough bone quantity and adequate bone quality for mini-screw insertion. The insertion site with the optimal anatomic characteristics is the buccal bone corresponding to the distal root of second molar, with screw insertion 4 mm buccal to the cementoenamel junction. Considering the cortical bone thickness of optimal insertion sites, pre-drilling is always recommended in order to avoid high insertion torque.

Does Low-Level Laser Therapy Enhance the Efficiency of Orthodontic Dental Alignment? Results from a Randomized Pilot Study.

OBJECTIVE: To assess if low-level laser therapy (LLLT) enhances the efficiency of orthodontic dental alignment. BACKGROUND: There is no evidence of the effect of LLLT on the orthodontic treatment time from randomized clinical trials. METHODS: Thirty-six subjects were included in this interventional pilot study and randomly assigned for treatment with fixed appliance and LLLT (test group) or with fixed appliance only (control group). A single monthly administration of LLLT was performed intraorally using a Diode laser (980 nm, 1 W, continuous wave, total energy density = 150 J/cm2; Doctor Smile-Lambda Spa). The date of brackets bonding (T1) and the date of complete resolution of dental crowding (T2) were recorded. The alignment treatment time was defined in days as T2 - T1. The number of monthly scheduled control visits was also recorded. Treatment time duration was assessed in both groups with the log-rank (Mantel-Cox) Test for survival analysis. Mann-Whitney U tests was used to compare the number of control visits from T1 to T2 between the two groups. RESULTS: Patients' age, sex, and amount of crowding were equally distributed between the two groups. The alignment treatment time was significantly shorter (p < 0.001) in the tested group (211.8 days) compared to the control (284.1 days). Consequently, control visits (p < 0.001) were lower in the test group (7 visits, median value) compared to the control group (9.5 visits, median value). CONCLUSIONS: The results of this pilot study suggest that the administration of LLLT might significantly increase the efficiency of orthodontic treatment during dental alignment.

A New Approach for the Treatment of Lateral Periodontal Cysts with an 810-nm Diode Laser.

The aim of this study was to test whether the combination of diode laser therapy and surgical treatment for a lateral periodontal cyst (LPC) would result in greater clinical improvement compared with surgery alone. A total of 18 patients with LPCs were assessed for eligibility for this study. At baseline, each patient was randomly allocated to one of two regimens: diode laser plus surgery (test group) or traditional surgical treatment alone (control group). Healing parameters were assessed at 7 to 21 days to monitor short-term complications, and periodontal parameters were assessed at 3, 6, and 12 months to evaluate long-term healing. The test group demonstrated highly significant differences in both the short-term and long-term parameters compared with the control group. This study showed that diode laser treatment results in a shorter wound-healing period and could be considered valuable for the surgical treatment of LPCs.

The effect of a functional appliance in the management of temporomandibular joint disorders in patients with juvenile idiopathic arthritis.

BACKGROUND: Patients affected by juvenile idiopathic arthritis (JIA) may have several craniofacial growth disturbances and involvements at the temporomandibular joint (TMJ). The objectives of the present study were to evaluate the clinical effectiveness of functional therapy used to reduce asymmetry of mandibular growth and TMJ disorder in patients with JIA. METHODS: By a retrospective longitudinal design, a cohort of 54 patients with JIA (mean age, 13.2±3.7 years; range, 5-17.7 years) and with TMJ involvements was enrolled in the study. Each patient, following the collection of clinical parameters, was treated for 24 months with a functional appliance individually customized by acrylic resin and resilient stainless steel with posterior and anterior metallic bite planes preventing the teeth from intercuspal contact. To evaluate differences before (T0) and after therapy (T1) of the clinical TMJ parameters, the statistical analysis by the χ2 Test was performed. RESULTS: All the patients completed successfully the study. In patients with JIA, the use of a functional appliance determined a statistically significant difference of the pain during jaw movement, maximal mouth opening, TMJ sounds and crepitations (P<0.001) and TMJ click, significantly reduced at T1 (P<0.05). CONCLUSIONS: The use of an orthodontic functional appliance determined a significant improvement, at 24 months, in many TMJ signs and symptoms in patients affected by JIA and with TMJ disorders. This study suggests that children and adolescents with JIA which presented either unilateral or bilateral moderate to severe TMJ involvement, if not treated, should be develop severe disturbances during growing.

Diagnostic concordance between skeletal cephalometrics, radiograph-based soft-tissue cephalometrics, and photograph-based soft-tissue cephalometrics.

OBJECTIVE: This study aims to investigate the diagnostic concordance between skeletal cephalometrics and soft-tissue cephalometrics in identifying facial lower third characteristics. MATERIALS AND METHODS: We compared a skeletal cephalometric analysis (SCA) to a soft-tissue analysis performed on cephalometric radiographs (rSTCA) and to one performed on profile photograph (pSTCA). Ninety-six pre-treatment digital lateral cephalometric radiographs and 96 digital profile photographs were randomly selected for this study (patients' mean age: 18.33, SD: 3.38, age range: 14-29). Inclusion criteria were as follows: no skeletal asymmetry, well-aligned upper and lower dental arches, no history of orthodontic treatment, prosthodontic treatment, facial surgery and trauma, patient's age between 14 and 30 years, high-resolution images, exams taken with natural head position. Kruskas-Wallis and post hoc pairwise comparisons tests were used to find differences among the considered cephalometric methods. The diagnostic performance of the three methods was also assessed using the receiver-operating characteristic (ROC) curve analysis. RESULTS: Significant differences were found between SCA and rSTCA and between SCA and pSTCA in defining sagittal and vertical facial lower third characteristics (P < 0.05). No differences were found between rSTCA and pSTCA (P > 0.05) for the same facial characteristics. For each parameters investigated, pSTCA showed an area under the curve much closer to the perfect value of 1.00. CONCLUSION: Poor diagnostic concordance was found between SCA and rSTCA and between SCA and pSTCA. pSTCA is a reliable method for evaluating the soft-tissue profile characteristics compared to that performed on cephalograms.

Mechanobiology of the tooth movement during the orthodontic treatment: a literature review.

Orthodontic tooth movement differs significantly from the physiological tooth movement, as it determines a biological response of the surrounding tissues of the teeth, resulting in a remodelling of the periodontal ligament and the alveolar bone. The result is a biochemical adaptive response to the application of the orthodontic force with the reorganization of the intracellular and the extracellular matrix, in addition to a change of the local vascularization. This in turn leads to the synthesis and the release of arachidonic acid, growth factors, metabolites, cytokines and various enzymes. Biologically, not only the intensity of the force, but also its duration and the tissue response to the application of the same are important for tooth movement. Having these insights it will possible to examine the concept of optimal orthodontic force, a determining factor for the success of orthodontic treatment. The purpose of this revision was to describe the biological processes and future perspective of the application of orthodontic force, by providing relevant information to understand the changes at the molecular and cellular level occurring when the tissues are subjected to such forces. Knowledge on the subject of mechanics and biology in orthodontics is constantly growing, producing an increasingly strong basis for clinical success.

Mechanobiology of the tooth movement during the orthodontic treatment: a literature review.

Orthodontic tooth movement differs significantly from the physiological tooth movement, because it effects a biological response of the surrounding tissues of the teeth, resulting in a remodeling of the periodontal ligament and the alveolar bone. The result is a biochemical adaptive response to the application of the orthodontic force with the reorganization of the intracellular and the extracellular matrix, in addition to a change of the local vascularization. This in turn leads to the synthesis and the release of arachidonic acid, growth factors, metabolites, cytokines and various enzymes. Biologically, not only the intensity of the force, but also the duration of this and the tissue response to the application of the same are important for the purpose of tooth movement. Having these insights it will possible to examine the concept of optimal orthodontic force, a determining factor for the success of orthodontic treatment. The purpose of this revision is to describe the biological processes and future perspective that occur following the application of orthodontic force, by providing relevant information to understand what are the changes at the molecular and cellular level that undergo when the tissues are subjected to such forces. More knowledge on the subject of mechanics and biology in orthodontics are constantly growing, producing an increasingly strong basis for clinical success.

Effectiveness of orthodontic treatment with functional appliances on maxillary growth in the short term: A systematic review and meta-analysis.

INTRODUCTION: The aim of this systematic review was to evaluate the treatment effects on maxillary growth of removable functional appliances that advance the mandible to a more forward position in patients with Class II malocclusion. METHODS: Sixteen electronic databases and reference lists of studies were searched up to April 2015. Only randomized clinical trials and prospective controlled clinical trials investigating Class II growing patients treated with removable functional appliances were included. Two authors independently accomplished study selection, data extraction, and risk of bias assessment. All pooled analyses of data were based on random-effects models. Statistical heterogeneity was evaluated. RESULTS: In total, 14 studies were included (5 randomized clinical trials, 9 prospective controlled clinical trials) that collected data from 765 patients (405 treated, 360 untreated controls). The mean differences in treatment effect of functional appliances, relative to the untreated controls, were -0.61° per year (95% CI, -0.69° to -0.25°) for SNA angle, -0.61 mm per year (95% CI, -0.90 to -0.32 mm) for anterior maxillary displacement, and +0.07° per year (95% CI, -0.17° to +0.32°) for maxillary plane rotation. CONCLUSIONS: Removable functional appliances in Class II growing patients have a slight inhibitory effect on the sagittal growth of the maxilla in the short term, but they do not seem to affect rotation of the maxillary plane.

Periodontal biotype: characteristic, prevalence and dimensions related to dental malocclusion.

BACKGROUND: Knowledge of periodontal anatomy is essential when performing surgical and non-surgical procedures in the field of oral healthcare. Gingival biotype is often assessed for this purpose. The aim of this study was to assess the prevalence of the gingival biotypes in a group of patients and to evaluate if the gingival biotypes were related with the different types of Angle's classification of malocclusion. METHODS: The study was performed on 76 volunteer patients (38 males, 38 females, mean age 14.7 years old). Gingival biotypes were assessed with the evaluation on the translucence of a periodontal probe through the gingival margin of the tooth during the probing, at the mid facial aspect of both maxillary central, lateral incisors and canine; on each patient, Angle's classification of malocclusion was also recorded. RESULTS: The prevalence in the whole sample of thin gingival biotype was 43.4% and thick gingival biotype was 56.6%. The frequency of female with thin gingival biotype was significantly less respect to male patients (42.4% and 55.6%, respectively) while the thick gingival biotype was higher in the female respect to male patients (55.8% and 44.2%, respectively) (χ2=1.339, P=0.247). There was not a significant association between type of malocclusion and gingival biotype (P=0.143). There was however a prevalence of thick gingival biotype in patient with class II malocclusion and a slight prevalence of thin gingival biotype in patient with class I malocclusion. CONCLUSIONS: No relationship was found between gingival biotypes and Angle's classification of malocclusion. In this sample, a higher prevalence of thick gingival biotype especially among female subjects was observed.

Reliability and efficacy of palifermin in prevention and management of oral mucositis in patients with acute lymphoblastic leukemia: a randomized, double-blind controlled clinical trial.

BACKGROUND: Myeloablative and hematopoietic stem cells transplantation therapy (HSCT) often acts as side-effect to oral mucositis (OM) with no effective treatment. This randomized-controlled trial analyzed the efficacy of palifermin, administered as a dose during HSCT therapy, as primary prophylaxis on pediatric patients with acute lymphoblastic leukemia (ALL). METHODS: In this study forty-six patients (9-15 years) with B-cell acute lymphoblastic leukemia (B-ALL) were analyzed. The patients underwent allogenic HSCT conditioned by myeloablative regimen. Subsequently to randomization, patients in the palifermin group were assigned to receive palifermin, 60 mg/kg, intravenously as a single dose 3 days before and after transplant conditioning regimen cycle. The patients in the Control group received only a placebo treatment. Maximum severity of OM, incidence and duration of ulcerative OM, incidence and duration of severe OM limitations were evaluated. RESULTS: A statistically significant reduction in the incidence of OM up to grade 3 in the palifermin group compared to the control group was discovered. There was also a reduction, confirmed at 60 days, in the degree of severity of mucositis in the palifermin group, with an average of 1.54 grade in the palifermin group, and of 2.16 in the Control group and in the use of opioid analgesics. CONCLUSIONS: This study indicates that a single dose of palifermin used as primary prophylaxis during HSTC therapy can prevent severe OM in pediatric patients with ALL and used as secondary prophylaxis can prevent the recurrence of severe OM in high-risk patients with previous mucosal injury and improves the quality of life in pediatric patients with ALL.

Occlusal and MRI characterizations in systemic sclerosis patients: A prospective study from Southern Italian cohort.

OBJECTIVES: The aim of the present study was to assess the prevalence of temporomandibular joint (TMJ) symptoms, clinical and magnetic resonance imaging (MRI) findings in a cohort of Southern Italian patients with SSc. METHODS: Twenty-seven patients with SSc (12 diffuse, 15 limited, mean age 53.9, SD±1.2) and 28 healthy subjects (mean age 54.8, SD±4.2) were enrolled in this observational cohort study. In all patients, clinical examination for assessing the presence of TMJ sounds, pain in the TMJ area, tenderness of masticatory muscles, limited mouth opening, pain assessment, MRI scan and Anamnestic and Dysfunctional Index were performed. RESULTS: The test groups reported more clinical and MRI findings of TMJ symptoms and dysfunction than control group. The frequency distributions of symptoms were significantly different (P<0.05), in the test groups for TMJ sounds, pain during mandibular movement and difficulty in the maximum mouth opening. There was also a significant decrease (P<0.001), in the test groups, in the mean of leftward, rightward laterotrusion and protrusion. Correlation analysis allowed to affirm that maximum opening leftward laterotrusion, protrusion and click were significantly correlated to Modified Rodnan Skin Score. The mean duration of disease was significantly correlated, ever in total SSc group, only for the maximum mouth opening value. CONCLUSION: This study demonstrates that TMJ involvement is common in SSc patients and is correlated with a length and involvement of disease and supports the notion that TMJ examination should be encouraged in the rheumatology setting and clinicians should provide a right pain management and patient support.

Transglutaminase 2 up-regulation is associated with RANKL/OPG pathway in cultured HPDL cells and THP-1-differentiated macrophages.

Recent evidence emphasized that transglutaminase 2 (TG2), a protein cross-linking enzyme, may play a role in the early phase of inflammation. High levels of TG2 have been associated with the constitutive activation of nuclear factor-kappa B (NF-κB) that is considered the main regulator of inflammation. In this context, the receptor activator of NF-kappa B ligand (RANKL) and receptor activator of NF-κB have extensive functions in the regulation of cytokine secretion associated with different pathological conditions. The human periodontal ligament (HPDL) cells, which express and secrete osteoprotegerin (OPG) and RANKL, represent an useful "ex vivo" model for monitoring cell response in inflammatory microenvironments, such as periodontitis-dependent tissue response. Thus, we evaluated TG2 expression and alterations in RANKL/OPG ratio occurring in cultured HPDL cells. The HPDL cells were obtained from patients with chronic periodontitis (CP) and healthy subjects. We observed the up-regulation of some inflammatory markers, such as IL-6, TNF-α, and HMGB-1, and at the same time an increase in TG2 mRNA levels in HPDL cells from CP patients compared with healthy subjects. We found a positive correlation between RANKL/OPG ratio and TG2 mRNA levels in HPDL cells from CP patients. In the parallel experiments, we demonstrated that TG2 inhibition reduced RANKL expression in both HPDL cells from CP patients and monocytes differentiated to macrophages by tetradecanoyl phorbol acetate treatment. Given the RANKL key role in NF-κB pathway and the observed up-regulation of pro-inflammatory cytokines, our data suggest that TG2 may be involved in molecular mechanisms of inflammatory response occurring in periodontal disease.

Influence of bracket-slot design on the forces released by superelastic nickel-titanium alignment wires in different deflection configurations.

OBJECTIVE: To evaluate how different bracket-slot design characteristics affect the forces released by superelastic nickel-titanium (NiTi) alignment wires at different amounts of wire deflection. MATERIALS AND METHODS: A three-bracket bending and a classic-three point bending testing apparatus were used to investigate the load-deflection properties of one superelastic 0.014-inch NiTi alignment wire in different experimental conditions. The selected NiTi archwire was tested in association with three bracket systems: (1) conventional twin brackets with a 0.018-inch slot, (2) a self-ligating bracket with a 0.018-inch slot, and (3) a self-ligating bracket with a 0.022-inch slot. Wire specimens were deflected at 2 mm and 4 mm. RESULTS: Use of a 0.018-inch slot bracket system, in comparison with use of a 0.022-inch system, increases the force exerted by the superelastic NiTi wires at a 2-mm deflection. Use of a self-ligating bracket system increases the force released by NiTi wires in comparison with the conventional ligated bracket system. NiTi wires deflected to a different maximum deflection (2 mm and 4 mm) release different forces at the same unloading data point (1.5 mm). CONCLUSION: Bracket design, type of experimental test, and amount of wire deflection significantly affected the amount of forces released by superelastic NiTi wires (P<.05). This phenomenon offers clinicians the possibility to manipulate the wire's load during alignment.

Analysis of the characteristics of slot design affecting resistance to sliding during active archwire configurations.

BACKGROUND: During orthodontic treatment, a low resistance to slide (RS) is desirable when sliding mechanics are used. Many studies showed that several variables affect the RS at the bracket-wire interface; among these, the design of the bracket slot has not been deeply investigated yet. This study aimed to clarify the effect of different slot designs on the RS expressed by five types of low-friction brackets in vertical and horizontal active configurations of the wire. METHODS: Five low-friction brackets (Damon SL II, Ormco, Orange, CA, USA; In-Ovation, GAC International, Bohemia, NY, USA; Quick, Forestadent, Pforzheim, Germany; Time 2, AO, Sheboygan, WI, USA; Synergy, RMO, Denver, CO, USA) coupled with an 0.014-in NiTi thermal wire (Therma-Lite, AO) were tested in two three-bracket experimental models simulating vertical and horizontal bracket displacements. A custom-made machine was used to measure frictional resistance with tests repeated on ten occasions for each bracket-wire combination. Design characteristics such as the mesio-distal slot width, slot depth, and presence of chamfered edges at the extremities of the slot were evaluated on SEM images (SUPRA, Carl Zeiss, Oberkochen, Germany) and analyzed in relation to the data of RS recorded. RESULTS: Time 2 was found to show the higher frictional forces (1.50 and 1.35 N) in both experimental models (p<0.05), while Quick and Synergy brackets showed the lower frictional values in the vertical (0.66 N) and in the horizontal (0.68 N) bracket displacements, respectively. With vertically displaced brackets, the increased mesio-distal slot width and the presence of clear angle at mesial and distal slot edges increase the values of RS. With brackets horizontally displaced, the RS expressed by the wire is influenced simultaneously by the depth of the slot, the mesio-distal slot width, and the presence of clear angle at the extremities of the slot base, the clip, or the slide. CONCLUSION: In order to select the proper low-friction bracket system, clinicians should consider specific characteristics of slot design apart from the wire engaging method.