An Evaluation of the Rate and Type of Orthodontic Tooth Movement When Injecting Platelet-Rich Plasma During Mini-Implant-Based Segmented en-Masse Retraction of Upper Anterior Teeth.

INTRODUCTION: The study aimed to determine the influence of palatal injection of platelet-rich plasma (PRP) on the rate and type of orthodontic tooth movement (OTM) during the en-masse retraction of upper anterior teeth. MATERIALS AND METHODS: Two-arm parallel-group trial, in which 30 class II division 1 adult patients (7 males and 23 females) aged 16 to 27 years were recruited. The sample was randomly divided into two groups: the experimental group, in which PRP was injected in the palatal mucosa of the maxillary six anterior teeth immediately before starting the en-masse retraction of upper anterior teeth, whereas in the control group, traditional treatment was employed. Following the first premolar extraction, space closure was accomplished using frictionless mechanics for the en-masse retraction of upper anterior teeth. In both groups, a rigid segmented arch made of stainless steel with a diameter of 0.021 x 0.025 inch and an 8-mm power arm was used for the upper anterior teeth, and mini-implants were inserted between the upper second premolar and first molar at 8 mm apical from the archwire line. NiTi coil springs were used for retraction. Measurements were recorded at the onset of space closure (T0) and every 40 days till the middle of the en-masse retraction of upper anterior teeth (T1). RESULTS: Thirty patients completed the trial, and no patients were lost to follow-up in both groups. The OTM rate in the PRP group was similar to that of the control group (P = 0.596). The upper anterior teeth in the two groups were retracted mostly by controlled tipping and partially by translation. Statistically insignificant differences were observed between the two groups regarding the rest of the cephalometric variables. No serious harms were observed in either group. CONCLUSIONS: PRP was ineffective in accelerating the OTM rate during the en-masse retraction of upper anterior teeth and it did not affect the type of tooth movement.

Evaluating the Injection of Platelet-Rich Plasma on Second Lower Molars Protraction: A Randomized Controlled Clinical Trial.

Background The use of platelet-rich plasma (PRP) in dentistry was entered several decades ago, yet its clinical use in orthodontics still requires further investigation. The aim of this study was to evaluate the possible effects of local injection of PRP on the rate and type of mandibular second molar protraction movement compared with the comparator (no PRP) group. Material and methods Eighteen patients aged between 17 and 25 years were randomly allocated in a split-mouth study design to receive PRP injections on one side immediately before the start of molar protraction (PRP group), while the other side received only saline solution (comparator group). Eligibility criteria included bilaterally extracted mandibular first molars cases and indicated mandibular second molars protraction. The primary outcome of the study consisted of measuring the rate of molar protraction from the beginning of protraction (T0) to the end of the seventh month (TF), using a digital gauge. The secondary outcome included measuring the type of second molar protraction movement between T0 and TF by lateral cephalometric images. Randomization of the intervention side was performed by picking out opaque sealed envelopes. The blinding of the principal investigator was impossible but blinding of the patient was achieved by injection of saline. Analyses were done using paired samples T-test to compare the changes in all variables between T0 and TF. The level of significance was taken at a P-value < 0.05. Results No significant difference was detected between the PRP and comparator groups in the rate of second lower molar protraction during seven months (0.56±0.07 mm per month in the comparator group, whereas, was 0.6±0.11 mm per month in the PRP group). Molar protraction parameters in both groups showed second lower molars moving by controlled tipping closer to bodily movement (Root Movement:Crown Movement≈0.8). Conclusions Platelet-rich plasma (PRP) is ineffective in accelerating the rate of orthodontic tooth movement (OTM) during molar protraction, and it has no effect on the type of tooth movement. In addition, the mechanics that we used (6 mm power arm in combination with miniscrews) are effective in mandibular second molar protraction by controlled tipping closer to bodily movement.

The Effect of Elastic and Metallic Ligation Methods on the Unloading Forces for Three Different Types of Nickel-Titanium Archwires Inserted Into Metallic Brackets: An In-vitro Study.

INTRODUCTION: One of the unique properties of the nickel-titanium (NiTi) archwires is the release of light continuous forces with a wide range of activation, which is affected by the method of ligating the wire to the bracket. Both elastomeric modules and metallic ligatures are the most common components to ligate the archwire to the bracket. This study aimed to evaluate the effect of elastomeric versus metallic ligatures on the released forces of three types of rectangular 0.016- by 0.022-inch NiTi wires. MATERIALS AND METHODS: This investigation evaluated three different situations of ligating the NiTi archwires to metallic brackets. The produced forces by these wires were evaluated using a modified three-point bending test (a universal testing machine: Testometric 350M®, Instron, Lincoln Close, Rochdale, England). A 0.022-inch slot-size premolar bracket was used for this investigation with zero torque and zero angulation (Master Series®, American Orthodontics, Sheboygan, USA). The first situation involved no ligation to the metallic brackets using three types of NiTi wires, whereas the second situation (the elastic ligation) involved the use of colored elastomeric modules with a 0.045-inch inner diameter and a 0.115-inch outer diameter (Color Ligatures®, American Orthodontics, Sheboygan, USA) to ligate the archwire into the metallic bracket's slot. In the third situation (metallic ligation), stainless steel metallic ligatures with a 0.012-inch (Preformed Ligature Wire®, American Orthodontics, Sheboygan, USA) were used to perform the ligation. The employed NiTi wires were 0.016 x 0.022-inch in diameter (American Orthodontics®, Sheboygan, Wisconsin, USA), and they were of three different types: (1) the superplastic wires (NT3-SE®), the thermally activated wires at 25°C (Thermal Ti-D®), and the thermally activated wires at 35°C (Thermal Ti-Lite®). RESULTS: The thermally activated wires at 35°C (Thermal Ti-Lite®) recorded the lowest force levels for the three ligation methods, while the highest result appeared with the superelastic type (NT3-SE®) and the thermally activated type at 25°C (Thermal Ti-D®) which showed a varied force for different ligation methods. Regarding the three different NiTi wires used, the elastic and metallic ligation increased the force levels for the superelastic type (NT3-SE®) over non-ligation by 50% and 110%, respectively, whereas the elastic ligation raised only the forces for the thermal types (Thermal Ti-D® and Thermal Ti-Lite®) by 75% and 22%, respectively. Both thermally activated types (Thermal Ti-D® and Thermal Ti-Lite®) released forces in the elastic ligation method greater than that of the metallic method by 125% and 20%, respectively. CONCLUSION: The elastic ligation method raised the unloading forces in comparison with the non-ligation for all tested archwires, whereas the metallic ligation method raised the released forces for the superelastic type (NT3-SE®) and decreased those related to the activated types (Thermal Ti-D®, Thermal Ti-Lite®) due to the increased friction and the instability of the crystalline structure. Only the heat-activated type at 35°C (Thermal Ti-Lite®) reflected the unique properties of the NiTi wires in producing light continuous forces with a wide range of activations regardless of the type of ligation.

Evaluating the Elemental Composition, Transformation Behavior, Crystalline Structure, and Mechanical Properties of Three 0.016-Inch by 0.022-Inch Nickel-Titanium Archwires: An In Vitro Study.

Background Nickel-titanium (NiTi) archwires are considered the most attractive wires during the first stage of orthodontic treatment because of their unique properties throughout several generations. This study aimed to evaluate three different NiTi wires in terms of their elemental composition, transformation behavior, crystalline structure, and mechanical properties. Materials and methods The study used three different groups of NiTi archwires with dimensions of 0.016 x 0.022-inch (American Orthodontics®, Sheboygan, WI, USA). The first group included six superelastic NiTi archwires (NT3-SE®), with normal force and a stable structure that was not affected by temperature changes. The second group included six heat-activated NiTi archwires activated at 25°C (Thermal Ti-D®), with moderate force and a sensitive structure to thermal changes, especially at room temperature. The third group included six heat-activated NiTi archwires activated at 35°C (Thermal Ti-Lite®), with light force and a sensitive structure to thermal changes, especially at body temperature. X-ray fluorescence (XRF) was performed to determine wire element composition, whereas differential scanning calorimetry (DSC) was performed to determine the austenite finish temperature (Af). The X-ray diffraction (XRD) analysis was used to identify the crystalline structure at room temperature, and a three-point bending test was carried out under constant temperature (37°C) with respect to the instructions of ISO15841/DIS to evaluate the mechanical properties of these wires. Results The XRF analysis revealed that the superelastic NiTi archwires (NT3-SE) were composed of NiTi and chrome, whereas the heat-activated wires (Thermal Ti-D and Thermal Ti-Lite) were composed of NiTi and copper. The DSC showed the Af was at +16.84°C for the superelastic type (NT3-SE), +23°C for the heat-activated at 25°C (Thermal Ti-D), and +33.99°C for the heat-activated at 35°C (Thermal Ti-Lite). The XRD analysis identified the crystalline structure at room temperature for the superelastic type (NT3-SE) as austenite, while for thermal types (Thermal Ti-D and Thermal Ti-Lite) were a compound structure of austenite and martensite phase. Finally, the bending test showed that the highest forces were delivered from the superelastic type (NT3-SE), followed by heat-activated at 25°C (Thermal Ti-D), while the lowest forces were delivered from heat-activated at 35°C (Thermal Ti-Lite). There was no significant difference between the superelastic type (NT3-SE) and thermally activated type at 25°C (Thermal Ti-D), while there was a significant difference between the two previous types and the thermally activated type at 35°C (Thermal Ti-Lite) for all studied unloading points. Conclusions The thermal types of archwires (Thermal Ti-D and Thermal Ti-Lite) had lower unloading values in comparison with the superelastic type (NT3-SE). The elemental composition was different between the superelastic wires and the thermal ones. The superelastic wires were also different from the other two types in terms of crystalline structure. The three types of archwires had an activation degree located in the range of oral cavity variations.

p53 expression in pleomorphic adenoma of salivary glands: A systematic review and meta-analysis.

OBJECTIVE: There are conflicting data regarding immunohistochemical expression of p53 in pleomorphic adenoma. This systematic review and meta-analysis aimed to examine whether p53 expression has a role in the pathogenesis of pleomorphic adenoma. DESIGN: A comprehensive literature search for relevant studies published from 2000 up to end of 2014 was performed using PubMed, EMBASE and the Cochrane Library Databases. Only articles in which p53 detected by immunohistochemical staining were included. The meta-analysis was done using Comprehensive Meta-Analysis software. RESULTS: Eighteen eligible studies were included in this meta-analysis. Heterogeneity measures showed a statistically significant Cochrane Q value (P-value<0.001). The random effects model showed an effect size of 0.254 with a 95% CI (0.139-0.417). The overall p53 positivity is 25.4%. CONCLUSION: Mutant p53 has to be detected by more precise techniques to emphasize on its role in development of pleomorphic adenoma of salivary gland.

Importance of dental records in forensic dental identification.

INTRODUCTION: The patient's record maintains all the diagnostic information with regards to patients and contains valuable information that can be beneficial to the dentist as well as legal authorities during forensic human identification. AIM: Objective of the study was to compare dental records with an ideal dental record form, as well as to compare between dental records of private clinics and academic hospitals and to assess the awareness and the knowledge of the dentists regarding the maintenance of their dental records accurate for medico-legal purposes. MATERIAL AND METHODS: A comparative cross-sectional study between records kept in private clinics and academic teaching hospitals in Khartoum locality. RESULTS: Our results showed that Students are more likely to encounter accurate dental records more than dentists in private clinics. In conclusion Students are more aware regarding medicolegal purposes of maintenance of dental records. Accurate maintenance of dental records is more among dental students. Therefore, private clinics encounter dental records as financial documents.