Orthodontic Miniscrews Research Articles

Comparison between Topical and Injection Anesthetics on Pain Related to Orthodontic Miniscrew Placement: A Split-mouth Study

The aims of this study were to compare the anesthetic effect of a lidocaine/prilocaine (L/P) topical anesthetic with placebo on pain from needle sticks and to compare the anesthetic effect of the L/P topical anesthetic with an infiltrative anesthetic on pain from orthodontic miniscrew placement. Pain elimination was analyzed from two interventions: (a) needle stick and (b) miniscrew insertion. When assessing pain from needle stick, one side of the mandible received 2.5% lidocaine/2.5% prilocaine topical anesthetic, and the other side received placebo. When evaluating pain from miniscrew placement, one side of the mandible received L/P topical anesthetic and the other side received infiltrative anesthetic. The findings were recorded on a Visual Analogue Scale after needle stick and after miniscrew placement. Subjective assessment was analyzed by a questionnaire. The L/P topical anesthetic significantly eliminated the pain from needle stick (Mann-Whitney test of medians, 29.0 vs 0.0, respectively, p<0.001). However, the injection anesthetic eliminated the pain from the miniscrew placement better than the L/P topical anesthetic (Mann-Whitney test of medians, 0.0 vs 5.5, respectively, p<0.001). Eighty percent of the subjects felt more comfortable with L/P topical anesthetic than injection anesthetic. Pain from needle stick pain was reported to be the most uncomfortable part of the study. The L/P topical anesthetic efficiently eliminated pain from needle stick. The L/P topical anesthetic did not completely eliminate pain from miniscrew placement as the injection anesthesia, but it did reduce pain to tolerable levels. L/P topical anesthetics can significantly eliminate pain from needle stick injections, and L/P topical anesthetics can reduce pain from orthodontic miniscrew placement to tolerable levels.

Effect of surface treatment on the mechanical stability of orthodontic miniscrews.

To provide collective quantitative evidence about the effect of surface treatments on the mechanical stability of orthodontic miniscrews (MSs). The study was registered in PROSPERO (No. CRD42020209652). The research question was defined according to the PICO (population, intervention, control, and outcomes) format. Various research databases were searched for animal and human studies on effects of surface treatment on the mechanical stability of MSs. Both prospective and retrospective in vivo clinical studies published in English were included. The risk of bias was assessed using SYRCLE's risk of bias tool for animal studies. The meta-analysis was conducted using RevMan 5.4. A total of 109 articles were identified; 14 were included in the systematic review, and seven studies with sandblasting, acid etching (SLA) methods of surface treatment were included for meta-analysis. The number of study participants ranged from 6 to 24 (total n = 185), with a mean of 13.2. A total of 949 MSs were used with a mean of 67.8. The overall success rate for surface-treated MSs ranged from 47.9% to 100%. Forest plot of removal torque values showed significantly higher values for SLA surface-treated MSs compared with controls with a standard mean difference of 2.61 (95% confidence interval = 1.49-3.72, I2 = 85%). Forest plot of insertion torque showed a standard mean difference of -6.19 (95% confidence interval = -13.63-1.25, I2 = 98%, P = .10). Surface treatment of MSs improved primary and secondary stability with good osseointegration at the bone-implant surface. However, significant heterogeneity across the studies included in the meta-analysis made it difficult to draw conclusions.

Cortical bone microdamage produced by micro-osteoperforation screws versus orthodontic miniscrews: an in vitro study

Abstract Background/objective The alternative use of Orthodontic Miniscrew Implants (OMIs), traditionally used for skeletal anchorage, to facilitate micro-osteoperforations (MOPs) for accelerating orthodontic tooth movement has been reported in previous studies. The objective of the present in vitro study was to compare the microdamage generated by OMIs and MOP-purposed screws of similar dimensions in porcine cortical bone. Materials and methods Forty rectangular porcine cortical bone specimens of 1.5 mm thickness were produced and divided into two equal groups. According to group allocation, either a single MOP screw or OMI was inserted and later removed. A sequential staining protocol was carried out to distinguish true microdamage created upon screw insertion and removal from iatrogenic damage. The bone specimens were imaged by a confocal laser scanning microscope, and five histomorphometric measurements described and quantified the generated microdamage. Results On the entry (outer) bone surface, the OMI screws produced greater microdamage which reached statistical significance across all of the histomorphometric parameters. In contrast, a statistically significant increase in microdamage was created following MOP screw insertion on the exit (inner) bone surface, but only in three assessment parameters, recorded as total damage area, as well as diffuse damage area and radius. Conclusions Overall, the present study showed that 1.5 mm OMIs produced slightly greater microcrack-type and diffuse damage-type microdamage than the 1.6 mm diameter MOP screws. However, these differences were small and considered clinically insignificant.

Cone-Beam Computed Tomographic Assessment of Bone Thickness in the Mandibular Anterior Region for Application of Orthodontic Mini-Screws.

To determine the proper zones for placement of orthodontic mini-screws, based on cone-beam computed tomography (CBCT) measurements in the anterior mandibular region. The current cross-sectional study was performed on CBCT images of 77 individuals in the age range of 18-60 years. Axial slices at the levels of 2, 5, and 8 mm from the cementoenamel junction (CEJ) of the mandibular anterior teeth were selected. Interdental distances were measured in the mesiodistal direction, parallel to the midline of the mandibular arch. Areas with more suitable width were investigated for measuring the minimum interdental space. On the reconstructed cross-sectional images, labiolingual thickness of the bone was measured at the levels of 2, 5, 8, and 11 mm from the CEJ. The Kruskal-Wallis test, Mann-Whitney test with Bonferroni correction, Welch test, and Tukey's multiple analogy test were used to analyze the data. Mesiodistal and labiolingual distances between the roots in every measured region had the highest values at the levels of 8 and 11 mm from the CEJ. The highest measured values were related to the interdental region between the lateral incisor and canine teeth on both sides of the arch. There were no statistically significant differences between these values (P < .001). The lateral incisor-canine areas at the level of 8 mm from the CEJ are introduced as the optimal sites for placement of orthodontic mini-screws. In addition, the results recommend the application of mini-screws with 1.3-1.7 mm diameter and 5-7 mm length.

Stability and success rate of dual-thread miniscrews.

To date, the clinical stability of dual-thread orthodontic miniscrews has not been studied. This study aimed to compare the primary stability and long-term clinical success rate of dual-thread and cylindrical orthodontic miniscrews and to examine the association between various clinical factors and the success rate of miniscrews. A total of 145 cylindrical and 135 dual-thread miniscrews were inserted in the maxillary and mandibular buccal alveolar areas of 142 patients. The torque and Periotest (Siemens, Bensheim, Germany) values were recorded during insertion and removal. The effect of clinical variables such as sex, age, screw design, jaw, side of placement, root proximity, and site of placement on the success rate was examined using logistic regression analysis. There was no statistically significant difference (P = .595) in the overall clinical success rate between the two designs, with an overall success rate of 82.1% and 84.4% for the cylindrical and dual-thread miniscrews, respectively. Age and screw-root proximity were significantly associated with failure (P < .05). The dual-thread miniscrews did not show superior long-term stability and clinical success rate as compared with the cylindrical miniscrews. The results of this study suggest that patient age and screw-root proximity influence the clinical success rate of miniscrews.

Reduction of Insertion Torque on Orthodontic Mini-screw Implant by means of Reduced Friction

In this article, the reduction of insertion torque on the orthodontic mini-screw implants (OMI) was studied. Three types of diamond-like carbon (DLC) films (DLC, Si-DLC, and F-DLC) were deposited on the OMIs by plasma-based ion implantation technique. The maximum insertion torque (MIT) value was measured using a physiodispenser during insertion on a mandibular pig jaw. Ten OMIs of each condition were used to evaluate the MIT values compared to the Ti-6Al-4V typed OMI. The statistical analysis of data was analyzed by One-way analysis of variance (ANOVA) and Tukey HSD. The results indicated that the Ti-6Al-4V showed the highest MIT but not significantly different from the F-DLC (P &gt;0.05). DLC and Si-DLC showed a significant reduction in MIT comparing to the Ti-6Al-4V (P &lt;0.05). However, the Si-DLC showed the lowest MIT among groups (P &lt;0.05). This phenomenon was due to the decreasing friction coefficient during OMI's insertion on a mandibular pig jaw. Therefore, the DLC coating, especially Si-DLC, could reduce the MIT value of OMI. It is thought that the lowering friction coefficient yields the lowering of MIT value. Keywords: Diamond-like carbon, Friction, Insertion torque, Mini-screw implant

Clinical effectiveness of orthodontic miniscrew implantation guided by a novel cone beam CT image-based computer aided design and computer aided manufacturing (CAD-CAM) template.

BackgroundAlthough miniscrews are widely used in orthodontic treatment as temporary anchorage devices, their correct and safe placement has attracted little attention. This study aimed to introduce a novel cone beam CT (CBCT) image-based computer aided design and computer aided manufacturing (CAD-CAM) template for orthodontic miniscrew implantation and to evaluate the effectiveness of miniscrews implanted under the guidance of this template.MethodsThe CBCT scans of ten patients requiring miniscrews as anchorage were analyzed in NNT software to predetermine the insertion sites of miniscrew implants. The DICOM data of the scans, along with virtual miniscrews acquired in Solidworks software, were imported into Mimics software to construct three-dimensional (3D) images of teeth and bone and to determine the virtual position of miniscrews and 3D virtual templates were designed following consideration of the virtual implantation plans. A STL (Stereolithography) file of the virtual template was output, and the resin template was then fabricated with a stereolithographic appliance (SLA). 24 Miniscrews were then implanted guided by the template and clinical evaluation of their safety and stability, as well as their placement deviations, were made. A dental casts model and cephalometric analysis before and after orthodontic treatment were made to assess the dentomaxillofacial changes.ResultsAll 24 miniscrews had no contact with adjacent roots. 18 miniscrews had a grade I safety score and six had a grade II. The miniscrews were stable at 1, 3, 6, and 9 months after implantation, although there was mild inflammation around two miniscrews. Implantation deviation of miniscrew in the crown was (1.03±0.65) and (1.26±0.72) mm in the apex, on average. Satisfactory dentomaxillofacial changes in 10 patients with these 24 miniscrews as anchorage were acquired.ConclusionsMiniscrews could be implanted in the targeted position safely and precisely when guided by the novel templates, and remained stable during orthodontic treatment. Patients treated with these miniscrews as anchorage in orthodontic treatment acquired satisfactory dentomaxillofacial changes.

Effect of Different Head Hole Position on the Rotational Resistance and Stability of Orthodontic Miniscrews: A Three-Dimensional Finite Element Study.

The orthodontic miniscrew is driven into bone in a clockwise direction. Counter-clockwise rotational force applied to the implanted miniscrew can degrade the stability. The purpose of this three-dimensional finite element study was to figure out the effect of shifting the miniscrew head hole position from the long axis. Two miniscrew models were developed, one with the head hole at the long axis and the other with an eccentric hole position. One degree of counter-clockwise rotation was applied to both groups, and the maximum Von-Mises stress and moment was measured under various wire insertion angles from −60° to +60°. All Von-Mises stress and moments increased with an increase in rotational angle or wire insertion angle. The increasing slope of moment in the eccentric hole group was significantly higher than that in the centric hole group. Although the maximum Von-Mises stress was higher in the eccentric hole group, the distribution of stress was not very different from the centric hole group. As the positive wire insertion angles generated a higher moment under a counter-clockwise rotational force, it is recommended to place the head hole considering the implanting direction of the miniscrew. Clinically, multidirectional and higher forces can be applied to the miniscrew with an eccentric head hole position.

Complications reported with the use of orthodontic miniscrews: A systematic review.

ObjectiveThe aim of this systematic review was to evaluate the complications and side effects associated with the clinical use of orthodontic miniscrews by systematically reviewing the best available evidence.MethodsA survey of articles published up to March 2020 investigating the complications associated with miniscrew insertion, in both the maxilla and mandible, was performed using 7 electronic databases. Clinical studies, case reports, and case series reporting complications associated with the use of orthodontic miniscrew implants were included. Two authors independently performed study selection, data extraction, and risk-of-bias assessment.ResultsThe database survey yielded 24 articles. The risk-of-bias assessment revealed low methodological quality for the included studies. The most frequent adverse event reported was root injury with an associated periradicular lesion, vitality loss, pink discoloration of the tooth, and transitory loss of pulp sensitivity. Chronic inflammation of the soft tissue surrounding the miniscrew with mucosal overgrowth was also reported. The other adverse events reported were lesion of the buccal mucosa at the insertion site, soft-tissue necrosis, and perforation of the floor of the nasal cavity and maxillary sinus. Adverse events were also reported after miniscrew removal and included secondary bleeding, miniscrew fracture, scars, and exostosis.ConclusionsThese findings highlight the need for clinicians to preliminarily assess generic and specific insertion site complications and side effects.

Versatile Uses of Crimpable Hooks

The crimpable hook is a widely accepted tool onto which active elements can be fixed to aid in orthodontic tooth movement. This clinical pearl aims at showing the different ways in which crimpable hooks can be used to better orthodontic treatment mechanics, which are Crimpable hooks used for buccolingual force mechanics and Crimpable hooks used in conjunction with orthodontic miniscrews. The above-mentioned simple methods aim to facilitate and make easy the attachment of force elements for various kinds of tooth movements. It can help the operator to save time, prevent unwanted side effects of forces, as well as reduce the need for ligature wires for the attachment of force systems onto implant heads or lingual sheaths.

Cephalometric evaluation of intrusion of maxillary posterior teeth by miniscrews in the treatment of open bite

The objective of this research was to investigate the effectiveness of orthodontic miniscrews for skeletal anchorage during anterior open bite treatment using cephalometric radiographs. This study sample included 20 patients (mean age, 14.71; standard deviation, 1.77) with an anterior open bite. A total of 250g of force was applied using elastic chains with anchorage from palatal miniscrew to an occlusal splint covering the posterior maxillary teeth. Cephalograms were obtained at the beginning of the treatment when the appliance was first applied and at the 8-month visit when treatment was completed. Paired t tests were used to identify statistically significant differences between initial and final measurements of skeletal and dental parameters. A decrease of 2.72±1.90° in the SN-GoGn angle and 3.63±1.87mm in the anterior height (N-Me) parameter in the cephalometric evaluations indicated a significant improvement of vertically increased facial dimensions, with the intrusion of the maxillary posterior teeth (P<0.05). Anterior rotation of the mandible was determined by a 1.76±1.09° increase in the SNB angle and a 1.86±0.90° decrease in the ANB angle (P<0.05). Reductions in the open bite amount by 5.8±0.90mm, Mx6-SN by 4.00±1.01mm, and Mx6-PP by 4.01±1.00mm were indicative of significant intrusion in the maxillary posterior teeth (P<0.05). The present study confirmed that palatal miniscrew and maxillary occlusal splint caused intrusion of the maxillary posterior teeth, a decrease in the anterior open bite, and mandibular advancement, with anterior rotation after the maxillary posterior intrusion. We concluded that the treatment method in our study was appropriate for patients with Class I and mild Class II malocclusions and open bite anomalies.

Torque Requirements and the Influence of Pilot Holes on Orthodontic Miniscrew Microdamage

This study aimed to quantify the microdamage to cortical bone of different thickness and the maximum insertion torque during orthodontic miniscrew implant (OMI) placement with and without a pilot hole. Forty-five porcine bone specimens were prepared with thicknesses of 1.5, 2 and 2.5 mm. Ten bone specimens per thickness had a pilot hole drilled prior to the insertion of an OMI, and the remaining 15 bone specimens had an OMI without a pilot hole inserted. Sequential staining was used to identify damage caused by bone preparation and surface microdamage from OMI insertion and confocal laser microscopy images were used to quantify damage characteristics. Of the five damage characteristics, only one decreased when a pilot hole was used for all bone specimens (p = 0.025), while two increased as cortical bone thickness increased (p = 0.0064, p = 0.0003). There was no evidence that maximum insertion torque differed according to pilot hole status (p = 0.1144) and increased as cortical bone thickness increased (p = 0.0001). The presence of a pilot hole had minimal effect on microdamage characteristics and no effect on maximum insertion torque. As cortical bone thickness increased, an increase in microdamage and in maximum insertion torque was observed.

Evaluation of Cortical Bone Microdamage and Primary Stability of Orthodontic Miniscrew Using a Human Bone Analogue.

Orthodontic miniscrews have gained popularity; however, they have some drawbacks, including screw loosening that results from bone resorption caused by excess microdamage created during screw insertion. Pilot hole preparation through the cortical bone is considered beneficial to avoid such microdamage, while an overly large pilot hole impairs primary stability. Hence, we used a human bone analogue to evaluate the microdamage and primary stability to estimate the optimal pilot hole size that would minimize the screw loosening risk. Ti6Al4V orthodontic miniscrews and 1.0-mm-thick synthetic cortical bone pieces were prepared. Various compressive loads were applied in indentation tests to test pieces’ surfaces, and the microdamaged areas were confirmed as stress-whitening zones. Screw insertion tests were performed in which a miniscrew was inserted into the test pieces’ pilot hole with a diameter of 0.7–1.2 mm in 0.1-mm intervals, and the stress-whitening area was measured. The insertion and removal torque were also measured to evaluate primary stability. The stress-whitening areas of the 1.0–1.2 mm pilot hole diameter groups were significantly smaller than those of the other groups (p < 0.05), whereas the 0.9 and 1.0 mm pilot hole diameter groups showed higher primary stability than other groups. In conclusion, the bone analogue could be utilized to evaluate microdamage in cortical bones and the primary stability of miniscrews.

Efficacy of compound topical anesthesia combined with photobiomodulation therapy in pain control for placement of orthodontic miniscrew: a double-blind, randomized clinical trial.

This study aims to investigate the effect of compound topical anesthetic (CTA) application combined with photobiomodulation therapy (PBMT) on the level of pain perceived during placement of miniscrews and 24 h post the procedure in the buccal side of the maxillary bone. This randomized, prospective, single-center, split-mouth, double-blinded study included 25 subjects (12 males and 13 females, aged 16 to 35). Two anesthetic techniques before implantation were performed including Profound gel +PBM with 980 nm diode laser and local anesthesia with 2% lidocaine hydrochloride. Then, the miniscrews with the size of 1.6 mm in diameter and 8 mm in length were placed with a hand driver in the buccal side of the maxillary bone. The pain immediately after miniscrew placement (T1), also 12 h (T2), and 24 h (T3) post the procedure were collected by visual analog scale (VAS). Data were analyzed by SPSS version 22. There were no statistically significant differences in mean VAS scores within or between CTA combined with PBMT or injection applications, immediately after miniscrew placement (P = 0.75), 12 h after miniscrew placement (P = 0.4), and 24 h after miniscrew placement (P = 1.0). Compound topical anesthetic combined with PBMT provided adequate local anesthesia for the placement of miniscrews in the buccal side of the maxillary bone.

Does YouTube™ Offer Reliable Information about Mini Screws?

Objective: The goal of the present study was to estimate the quality and accuracy of provided data of orthodontic mini-screws related YouTube™ videos. Materials and Methods: In this cross-sectional research, a systematic survey of YouTube™ videos about mini-screws was gathered by applying the term "mini screw." The first 200 videos were viewed and at the end, the study was based on 77 videos. Demographics of videos were recorded. The video content was scored using a 14-point score scale, which was used for the classification of low and high content video groups. The video information and quality index (VIQI) was used to evaluate the quality of videos. Descriptive statistic was used. Distribution of YouTube™ Video Demographics in Low and High content groups was done by using the Pearson Chi-squared test and Fisher exact test. The Mann–Whitney U-test was used to compare the quantitative data, which did not show normal distribution. Spearman's rho correlation analysis was used to investigate the relationships among the parameters. Significance was evaluated as P &lt; 0.05. Results: We sorted 72 videos as low and 5 as high content. Healthcare providers uploaded most of the videos (58.4%). Educational videos were found to be the most (97.4%). Insertion of mini screw (65%), indication, and mechanics (45.5%) were the most; while, cost, oral hygiene (3.9%), and annoyance (5.2%) were the least mentioned topics. The mean "Duration of the videos" and "comments" in the high score group was statistically higher than the low content group. The VIQI Total Scores were found to be significantly higher in the high content group. Conclusion: Although a great variety of information, is available on YouTube™, content was found to be insufficient. Specialists must be aware that patients can use those videos as learning resources, and guide their patients to obtain correct/actual information.

교정용 미니스크류의 cutting flute 형성이 삽입 및 제거 토크에 미치는 영향

본 연구는 교정용 미니스크류의 구조적 특징인 나사부의 길이 변화와 cutting flute의 형성이 삽입 및 제거 토크에 미치는 영향을 평가하기 위해 시행되었다. 미니스크류는 나사부의 길이가 각각 6.0 mm, 3.3 mm 2종류를 제작하였다. Flute 형성 영향을 살펴보기 위해 flute를 형성하지 않은 미니스크류 실험군과 flute를 형성한 실험군으로 나누었다. Flute 형성 시 미니스크류의 tip으로부터 6.0 mm인 경우는 4.0 mm 그리고 3.3 mm인 경우는 2.4 mm까지 flute를 원주상의 180°위치에 2개를 형성하였다. 또한 flute 형성의 영향을 살펴보기 위해 미니스크류의 tip으로부터 6.0 mm 경우는 4 mm 그리고 3.3 mm 경우는 2.4 mm까지 flute를 원주상의 180°위치에 2개를 형성하였다. 삽입 부위에 따른 피질골의 두께와 골밀도의 차이에 따른 영향을 배제하기 위해 피질골 두께 2 mm와 해면골 두께 10 mm의 인공골 Biomechanical Test Block (Sawbones Inc, Vashon, WA, USA)을 이용하였다. 인공골에 직경 1 mm 드릴로 guide hole을 형성하고 미니스크류를 수직하게 위치시킨 다음 0.1 N·cm 정밀도의 디지털 토크 게이지 (9810P, Aikoh Engineering Co., Japan)에 약 1.2 kg의 정하중을 가한 상태에서 나사부의 top까지 삽입하며 얻어진 최대 토크 값과 삽입 방향의 역방향으로 제거할 때의 최대 토크 값을 기록하였다. 길이 6.0 mm와 3.3 mm 미니스크류의 삽입 토크 값은 각각 (29.53±1.84) N·cm와 (26.84±2.15) N·cm, 그리고 제거 토크 값은 각각 (14.50±1.37) N·cm와 (13.15±2.89) N·cm를 보였으며 상호간에 통계학적으로 유의한 차이를 보이지 않았다(P>0.05). Flute의 형성으로 6.0 ㎜ 미니스크류에서는 삽입과 제거 토크 값이 각각 (30.13±1.97) N·cm와 (18.65±1.10) N·cm로 공히 증가되었는데 통계학적으로 유의한 차이를 보이지는 않았다(P>0.05). 길이 3.3 mm 미니스크류에서는 삽입과 제거 토크 값은 각각 (20.99±3.94) N·cm와 (11.32±2.03) N·cm로 공히 감소되었는데 삽입 토크 값에서만 통계학적으로 유의한 감소를 보였다(P<0.05). 미니스크류의 삽입과 제거 토크 값은 나사부의 길이가 2배 증가되는 경우에도 큰 폭으로 증가되지 않았고, flute 형성의 영향은 나사부의 길이에 따라 다르게 나타났다.

Effect of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys

Various types of titanium base alloys are utilized as implant materials and as minis crews in orthodontics. The purpose of the current study is to enhancing titanium-based alloys with the additions of Cobalt in different percentage (5%, 10%, and 15%) to enhance primary osteoblast attachment and implant tissue incorporation. the reaction between human MG63 osteoblast-like cells and titanium – cobalt alloy face is substantial in biomaterials and tissue engineering field. The major target was to estimate the proteomic response of MG63 osteoblast-like cells in various cobalt percentages. The samples with and without cobalt addition was produced by using powder technology in order to get an acceptable initial surface roughness. Also sample characterizations includes (scanning electron microscopy (SEM), X-ray diffraction (XRD), vitro test (Biocompatibility MTT assay with MG-63 Cells). Results obtained from XRD and microstructure observations, sample without cobalt addition refer to an alloy with single I± phase, while after the additions of cobalt in different percentage (5%, 10%, 15%) the samples consist of two I±-Ti and intermetallic compound Ti2Co and the amount of Ti2Co phase slightly increase with increasing cobalt content. From MTT assays Proliferation and cells attachment of MG63 were cultured after 2 days Cells grown for the pure titanium alloys possess finer and circular confines compared with the grown cells at (titanium – cobalt) alloys with all cobalt percentages. Rising cobalt percentage makes the MG63 cell sharper and enlarges which means cobalt aid to enhancing both cell proliferation and growth. Cytotoxicity Cell Viability results was kept, exhibition no kind of attack caused by titanium or cobalt materials, The feature, of cobalt additions, in contrast to commercial pure titanium alloys, is the presence of active and non- cytotoxic compound (Ti2Co) which presents several attractive features, make the surface more attractive to the bone . How to Cite this Article Pubmed Style Fatimah J. Al-Hasani. of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. SRP. 2020; 11(5): 804-813. doi:10.31838/srp.2020.5.119 Web Style Fatimah J. Al-Hasani. of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. http://www.sysrevpharm.org/?mno=131488 [Access: March 30, 2021]. doi:10.31838/srp.2020.5.119 AMA (American Medical Association) Style Fatimah J. Al-Hasani. of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. SRP. 2020; 11(5): 804-813. doi:10.31838/srp.2020.5.119 Vancouver/ICMJE Style Fatimah J. Al-Hasani. of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. SRP. (2020), [cited March 30, 2021]; 11(5): 804-813. doi:10.31838/srp.2020.5.119 Harvard Style Fatimah J. Al-Hasani (2020) of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. SRP, 11 (5), 804-813. doi:10.31838/srp.2020.5.119 Turabian Style Fatimah J. Al-Hasani. 2020. of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Reviews in Pharmacy, 11 (5), 804-813. doi:10.31838/srp.2020.5.119 Chicago Style Fatimah J. Al-Hasani. Effect of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. Systematic Reviews in Pharmacy 11 (2020), 804-813. doi:10.31838/srp.2020.5.119 MLA (The Modern Language Association) Style Fatimah J. Al-Hasani. Effect of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Alloys. Systematic Reviews in Pharmacy 11.5 (2020), 804-813. Print. doi:10.31838/srp.2020.5.119 APA (American Psychological Association) Style Fatimah J. Al-Hasani (2020) of Cobalt Addition on the Cytotoxicity and Cell Attachment of Titanium Reviews in Pharmacy, 11 (5), 804-813. doi:10.31838/srp.2020.5.119

Finite element analysis of C-expanders with different vertical vectors of anchor screws

C-expanders are tissue- and bone-borne maxillary expanders that are anchored by 6 orthodontic miniscrews, 3 on each side of the palate. The purpose of the study was to investigate the effect of C-expanders on the circummaxillary sutures and bucco-palatal axis of teeth in 3-dimensional finite element analyses when anchor screw vectors are different. Five expansion models were studied on the basis of the vertical positions of anchor screws on the palate. Anchor screws for models A, B, and C were placed symmetrically at 4mm, 7mm, and 15mm below the cementoenamel junction (CEJ), respectively. Anchor screws for models D and E were placed asymmetrically at 4mm and 15mm below CEJ and 7mm and 15mm below CEJ, respectively. Stress, displacement, and angular changes of the bone and teeth were measured in elastoplastic behavior models using a static-nonlinear simulation in an implicit method. Symmetrical and asymmetrical anchor screw placement with different vertical vectors were compared using finite element analyses on 5 models. Using different vectors of anchor screws for C-expanders does change the pattern of palatal expansion (null hypothesis was rejected). The current investigation presents a promising future of controlled asymmetric skeletal maxillary expansion when asymmetric maxillary architecture needs to be corrected for successful orthodontic outcomes without involving orthognathic surgeries.

Effect of Different Surface Designs on the Rotational Resistance and Stability of Orthodontic Miniscrews: A Three-Dimensional Finite Element Study.

High orthodontic forces and various directions of applied forces can be associated with loosening of the screw anchorage in the bone. Screw designs have been modified to increase the stability of the miniscrews. This research evaluates the influence of three-designs on the stability of orthodontic miniscrews. A conventionally cylinder-type miniscrew design (Bio-Action screw, Jin-Biomed co., Bucheon, Korea) was set as a control, and three conditions were studied based on modifications of this control design. Condition-1 has narrowed threads in the upper part of the screw; Condition-2 has a notch at the middle part; and Condition-3 has the combination of Condition-1 and Condition-2. The moment required to unwind the miniscrew to five degrees is tested, and the moment generated at the cortical bone and the trabecular bone were calculated with finite element analysis. Compared to the control, all three conditions showed a higher moment required to unwind the miniscrew and a higher moment generated at the cortical bone. At the trabecular bone, condition-2 and -3 showed higher moment than the control, and condition-1 showed similar moment to the control. Condition-3 required a higher overall moment to unwind the miniscrew. These findings validate the design modifications used to increase the rotational resistance.

Protração maxilar usando mini-implantes em paciente Classe III: relato de caso

Uma alternativa já consolidada ao tratamento ortopédico convencional com disjunção palatina e máscara facial para pacientes em crescimento com Classe III esquelética por deficiência maxilar é a utilização de ancoragem esquelética para protração da maxila. Seu uso elimina os efeitos dentários adversos da terapia convencional, como extrusão e mesialização de molares superiores, projeção de incisivos superiores e retroinclinação de incisivos inferiores. Além disso elimina a necessidade de uso de um dispositivo extra-oral, o que contribui para a motivação dos pacientes. As miniplacas são a forma de ancoragem esquelética mais usada para esse tipo de terapia, entretanto a necessidade de um passo cirúrgico para instalação e outro para remoção das placas representa um ponto desvantajoso para essa técnica, e dessa forma o uso de mini implantes foi proposto com a finalidade de promover protração maxilar eliminando o passo cirúrgico. Este trabalho se propõe a descrever a técnica de prostração maxilar apoiada em mini implantes ortodônticos, ilustrada através de um caso clínico de um paciente tratado com esta terapia, mostrando os resultados faciais e oclusais positivos alcançados.