Ana Maria Bolognese

In vitro antioxidant potential of medicinal plant extracts and their activities against oral bacteria based on Brazilian folk medicine

BACKGROUND AND OBJECTIVES This study aims to determine antibacterial activities of Cocos nucifera (husk fiber), Ziziphus joazeiro (inner bark), Caesalpinia pyramidalis (leaves), aqueous extracts and Aristolochia cymbifera (rhizomes) alcoholic extract against Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus mutans and Lactobacillus casei. The antioxidant activity and acute toxicity of these extracts were also evaluated. MATERIAL AND METHODS The plant extracts antibacterial activity was evaluated in vitro and the minimal inhibitory concentration (MIC) was determined by the broth micro-dilution assay. The bacterial killing kinetic was also evaluated for all extracts. In addition, the antibacterial effect of the extracts was tested in vitro on artificial oral biofilms. The acute toxicity of each extract was determined in according to Lorke [Lorke D. A new approach to practical acute toxicity testing. Arch Toxicol 1983;54:275-87] and the antioxidant activity was evaluated by DPPH photometric assay [Mensor LL, Menezes FS, Leitão GG, Reis AS, Santos TC, Coube CS, et al. Screening of Brazilian plants extract for antioxidant activity by the use of DPPH free radical method. Phytother Res 2001;15:127-30]. RESULTS MIC and the bactericidal concentrations were identical, for each evaluated extract. However, microbes of artificial biofilms were less sensitive to the extracts than the planktonic strains. A. cymbifera extract induced the highest bactericidal effect against all tested bacteria, followed by C. nucifera, Z. joazeiro and C. pyramidalis extracts, respectively. All extracts showed good antioxidant potential, being C. nucifera and C. pyramidalis aqueous extracts the most active ones. CONCLUSION In conclusion, all oral bacteria tested (planktonic or in artificial biofilms) were more susceptible to, and rapidly killed in presence of A. cymbifera, C. pyramidalis and C. nucifera than Z. joazeiro extracts, respectively. Thus, these extracts may be of great interest for future studies about treatment of oral diseases, considering their potent antioxidant activity and low toxicity.

Cone-beam computed tomography and radiographs in dentistry: aspects related to radiation dose.

Introduction. The aim of this study was to discuss the radiation doses associated with plain radiographs, cone-beam computed tomography (CBCT), and conventional computed tomography (CT) in dentistry, with a special focus on orthodontics. Methods. A systematic search for articles was realized by MEDLINE from 1997–March 2011. Results. Twenty-seven articles met the established criteria. The data of these papers were grouped in a table and discussed. Conclusions. Increases in kV, mA, exposure time, and field of view (FOV) increase the radiation dose. The dose for CT is greater than other modalities. When the full-mouth series (FMX) is performed with round collimation, the orthodontic radiographs transmit higher dose than most of the large FOV CBCT, but it can be reduced if used rectangular collimation, showing lower effective dose than large FOV CBCT. Despite the image quality, the CBCT does not replace the FMX. In addition to the radiation dose, image quality and diagnostic needs should be strongly taken into account.

Effects of Two Low-Intensity Laser Therapy Protocols on Experimental Tooth Movement

OBJECTIVE The purpose of this in vivo study was to determine the effect of two low-intensity laser therapy (LILT) protocols on macroscopic and microscopic parameters of experimental tooth movement. MATERIALS AND METHODS To induce experimental tooth movement in rats, 40 cN of orthodontic force was applied to the left first molars. Next, a gallium-aluminum-arsenide (Ga-Al-As) diode laser with a wavelength of 830 nm and power output of 100 mW was applied with fluence of 6000 J/cm(2) on the area around the moved tooth. Two different application protocols were used in the experimental groups: one with daily irradiation and another with irradiation during early stages. Macroscopic and microscopic analyses were performed at days 2 and 7 of tooth movement. The amount of tooth movement was measured with a caliper, and tartrate-resistant acid phosphatase and picrosirius staining were used to enable identification of osteoclasts and immature collagen, respectively. RESULTS The amount of tooth movement did not differ between the irradiated and nonirradiated groups on days 2 and 7 of the experiment. On day 2, no difference was observed in the number of osteoclasts or the percentage of immature collagen. On day 7, there was an increase in the number of osteoclasts after daily applications of LILT, while two applications produced no significant difference from control. The amount of immature collagen on the tension side significantly increased in the nonirradiated group and when LILT was applied for only 2 d, whereas it was shown to be inhibited by daily LILT applications (p < 0.05). CONCLUSION The tested LILT protocols were unable to accelerate tooth movement. Even though the number of osteoclasts increased when LILT was applied daily, the repair at the tension zone was inhibited.

Three-dimensional cephalometric study of upper airway space in skeletal class II and III healthy patients

Because the pharynx and the dentofacial structures have close relationship, a mutual interaction can be expected to occur between them. The literature presents skeletal malocclusion as etiology for airway morphology changes and/or vice versa. The present three-dimensional cephalometric study from computed tomography scans was carried out to investigate upper airway space in normal nasal breathing patients presenting skeletal pattern of classes II and III. In addition, the statistical analysis was done according to gender criterion. The results revealed that the majority of the airway measurements have not been affected by type of malocclusion. The three-dimensional technology used in this study also allowed the volume and surface area calculations, and no statistical significance was found. The retroglossal width and posterior nasal cavity height mean were larger in males than females in the class II group, but volume and cross-section area were not statistically significant. However, in class III group, although the differences in linear and angular measures means were not significant, the retropalatal volume and retroglossal volume and cross-section area were larger in males. The authors highlight that the evaluation of upper airway space should be an integral part of diagnosis and treatment planning to achieve functional balance and stability of the results.

Cervical vertebral maturation as a biologic indicator of skeletal maturity

OBJECTIVE To identify and review the literature regarding the reliability of cervical vertebrae maturation (CVM) staging to predict the pubertal spurt. MATERIALS AND METHODS The selection criteria included cross-sectional and longitudinal descriptive studies in humans that evaluated qualitatively or quantitatively the accuracy and reproducibility of the CVM method on lateral cephalometric radiographs, as well as the correlation with a standard method established by hand-wrist radiographs. RESULTS The searches retrieved 343 unique citations. Twenty-three studies met the inclusion criteria. Six articles had moderate to high scores, while 17 of 23 had low scores. Analysis also showed a moderate to high statistically significant correlation between CVM and hand-wrist maturation methods. There was a moderate to high reproducibility of the CVM method, and only one specific study investigated the accuracy of the CVM index in detecting peak pubertal growth. CONCLUSIONS This systematic review has shown that the studies on CVM method for radiographic assessment of skeletal maturation stages suffer from serious methodological failures. Better-designed studies with adequate accuracy, reproducibility, and correlation analysis, including studies with appropriate sensitivity-specificity analysis, should be performed.

Shear bond strength of orthodontic brackets to enamel under different surface treatment conditions.

The purpose of the present study was to evaluate the shear bond strength to enamel and the adhesive remnant index (ARI) of both metallic and polycarbonate brackets bonded under different conditions. Ninety bovine permanent mandibular incisors were embedded in acrylic resin using PVC rings as molds and assigned to 6 groups (n=15). In Groups 1 (control) and 3, metallic and polycarbonate orthodontic brackets were, respectively, bonded to the enamel surfaces using Transbond XT composite according to the manufacturers recommendations. In Groups 2 and 4, both types of brackets were bonded to enamel with Transbond XT composite, but XT primer was replaced by the OrthoPrimer agent. In Groups 5 and 6, the polycarbonate bracket bases were sandblasted with 50-μm aluminum-oxide particle stream and bonded to the enamel surfaces prepared under the same conditions described in Groups 3 and 4, respectively. After bonding, the specimens were stored in distilled water at 37°C for 24 hours and then submitted to shear bond strength test at a crosshead speed of 0.5 mm/min. The results (MPa) showed no statistically significant difference between Groups 4 and 6 (p>0.05). Likewise, no statistically significant differences (p>0.05) were found among Groups 1, 2, and 5, although their results were significantly lower than those of Groups 4 and 6 (p<0.05). Group 3 had statistically significant lower bond strength than Groups 2, 4, and 6, but no statistically significant differences were found on comparison to Groups 1 and 5. A larger number of fractures at the bracket/composite interface were evidenced by the ARI scores. OrthoPrimer bonding agent yielded higher bond strength in the groups using either conventional or sandblasted polycarbonate brackets, which was not observed in the groups using metallic brackets.

Long-term clinical outcome of rapid maxillary expansion as the only treatment performed in Class I malocclusion.

The purpose of this study was to investigate the long-term clinical responses of rapid maxillary expansion as the only treatment performed in Class I malocclusion using the Haas-type appliance. The longitudinal sample consisted of 90 sets of study models from 30 consecutive patients (12 males and 18 females) selected on the basis of the following inclusion criteria: all patients (1) had a Class I malocclusion with transverse maxillary/mandibular skeletal discrepancies, (2) were treated nonextraction in the early/ mid mixed dentition, (3) presented with mandibular dental arches with mild or no crowding, and (4) had no subsequent comprehensive orthodontic treatment implemented in either the maxilla or the mandible. The mean age was 8.2 years when treatment was initiated. Treatment outcomes were evaluated at pretreatment A1, short-term follow-up (one year after A1) A2, and long-term follow-up (four years after A2) A3. The changes in maxillary arch width and arch length were quantified and compared among assessment stages A1, A2, and A3 using the Students t-test. The results demonstrated a highly significant increase in maxillary arch width in both the short- and long-term follow-ups. The arch width increased significantly during treatment and decreased slightly during the long-term follow-up. The long-term clinical response demonstrated the efficacy and stability of this type of treatment in achieving maxillary arch width. The follow-up examination during the early/mid/permanent dentition confirmed the validity of overtreatment.

Treatment protocol to control Streptococcus mutans level in an orthodontic patient with high caries risk

The purpose of this article is to report a protocol for treating an orthodontic patient with a high risk of developing caries. The salivary level of Streptococcus mutans was evaluated during various stages of orthodontic treatment. It was significantly high before professional application of 1% chlorhexidine collagen gel, daily mouth rinsing with 0.05% sodium fluoride solution, and bonding of the bands and brackets. Although there were no other changes in hygiene habits, microbiologic tests showed that the microbiota was in balance during the follow-up periods. At the end of orthodontic treatment, periodontal health was observed, and enamel surfaces showed signs of remineralization.

How the lower face soft tissue changes after mandibular advancement or setback.

To contribute as an auxiliary tool for orthodontic and orthognathic planning and treatment, short-term changes on the lower face soft and hard tissues were investigated. All subjects presented adequate maxillary relation with the cranial base. The treatment was done by mandibular advancement in patients with skeletal class II or setback in skeletal class III, by the same oral surgeon, using the same technique, and rigid internal fixation. Lateral cephalograms were traced at the following intervals: T0-immediately before the surgical procedure, T1-6 months after surgery, and T2-1 year after surgery. The postoperative data of the lower face revealed highly significant changes for the soft tissue pogonion and lower lip, in the mandible advancement cases, whereas the underlying bone and dental structures remained constant. For the mandible setback cases, just the hard tissue pogonion variable displayed a statistically significant change.

Friction between different wire bracket combinations in artificial saliva: an in vitro evaluation

Objective The objective this work was to assess the friction coefficient between brackets and wires of different materials under conditions simulating the oral environment. Material and Methods Stainless steel (SS) and titanium-molybdenum alloy (TMA) wires of 0.019x0.025-in diameter (American Orthodontics) and polycarbonate bracket (American Orthodontics), ceramic bracket (American Orthodontics), and metal bracket (3M Unitek) with slots of 0.022x0.030-in were used. The friction coefficient was assessed by means of mechanical traction with the system immersed in artificial saliva. The mean roughness of both wire surface and bracket slots was evaluated by using a surface profilometer. Results The system using TMA wire and polycarbonate bracket had the highest roughness (p<0.05). SS wire with ceramic bracket had the highest friction coefficient, whereas the use of metallic bracket yielded the lowest (p<0.05). However, it was observed a statistically significant difference in the system using TMA wire and ceramic bracket compared to that using TMA wire and polycarbonate bracket (p=0.038). Conclusion Ceramic brackets in association with SS wire should be judiciously used, since this system showed a high friction coefficient.