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Article
The Effect of Dental Implant Length and Di-ameter on the Stress Distribution at the Im-plant-Bone Interface of the Immediate Load-ing Implants: A 3/D Finite Element Analysis

Authors: Talal H Mohamad --- Umer Al-Adel
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2013 Volume: 13 Issue: 21 Pages: 44-51
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: to evaluate the effect of implant length and diameter on the values and distribution of stresses of immediate loading implants by using three-dimensional (3D) finite elements (FE) analysis. Materials and Method: A 3-D FE model of an implant embedded in a block of bone was used in this study. The implant was LEADER/ ITALIA-Fix type which is specially designed for immediate loading. ANSYS V.12 program was used to build solid model of the implant and bone, and performing the finite element analysis. Two lengths of implant were used (11mm. and 13mm)., and two diameters (3.75mm. and 4.25mm.). Results: The results showed that the areas of maximum stress of all lengths and diameters are located at the neck of implants, the increase in the implant length from 11mm. to 13mm. leading to slightly increase in the stress at the implant-bone interface, while the increase in the diameter from 3.75mm. to 4.25mm. having no significant effect in increasing the value of stresses around dental im-plants. Conclusions: The increase in the implant length is negatively affect on stress values, but it leads to better dissipation of stresses around dental implant. The increase in the diameter having no obvious effect on stress values. However, it reduce the area of maximum stress at the implant neck


Article
Evaluation of Mechanical and Histological Significance of Nano Hydroxyapatite and Nano Zirconium Oxide Coating On the Osseointegration of CP Ti Implants

Authors: Majed Mohamed Refaat ماجد مجمد رفعت --- Thekra Ismael Hamad ذكرى اسماعيل حمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 3 Pages: 30-37
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Dental implant considers a unique treatment option for the replacement of missing dentition. The newtrend of implants is looking for materials which accelerate bone formation in bone implant interface and enhanceosseointegration to provide immediate loading directly after placement and decrease the time period which isdisturbs patients and uncomfortable. The aim of the study was to evaluate the effect of nano zirconium oxide (ZrO2)and nano hydroxyapatite (Hap) mixture coating of screw shaped commercially pure titanium (cpTi) implants onbond strength at the bone implant interface with torque removal test and histological analysis in comparison withnon coated implants.Materials and methods: Forty screws were machined from cpTi rods using a lathe machine. Then 20 screws coatedby electrophoretic deposition method by a mixture of nano hydroxyl apatite and nano zirconium oxide, while theother 20 screws remain uncoated. The tibia of 10 adult white New Zealand experimental rabbits was chosen asimplantation site, each rabbit tibia received 2 screws, one coated and the other uncoated. Torque removal test wasperformed to measure the torque required to remove the screw and histological analysis was performed to observethe new bone formation, after 2 and 4 weeks healing intervals.Results: Implant coated with a mixture of nano zirconium oxide and nano hydroxyl apatite showed a significantlyhigher removal torque values compared to uncoated one. There was more new bone formation with coatedimplants for both healing periods.Conclusions: Coating by electrophoresis considers a valuable process to coat metallic implants with a ceramicmaterial and to form a uniform composite layer of coating. Osseointegration improved at bone-implant interfaceassociated with the coated implants, which was illustrated by higher bone formation at the two intervals of time 2weeks and 4 weeks.


Article
A Comparative Study between Flapped and Flapless Surgical Techniques in Dental Implant Stability According to Resonance Frequency Analysis

Authors: Ali F. Hassan علي حسن --- Thair Abdul-Lateef ثائر عبد اللطيف
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 2 Pages: 92-97
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Recent implant surgical approach aims to cause less trauma, invasiveness and pain as much aspossible and to reduce patient and surgeon discomfort, time of surgery and time needed for functional implantloading. Flapless surgical techniques considered recently as one of the most popular techniques that may achievethese aims especially enhancing osseointegration and subsequently implant stability within less time than thetraditional flapped surgical technique. So this study aimed to make a comparison between flapped and flaplesssurgical techniques in resulted implant stability according to resonance frequency analysis RFA and in duration ofsurgical operation.Materials and methods: A total of 26 patients with 41 implants (one implant in the study group failed so it wasexcluded from the statistical analysis) were randomized into two groups: control group which involved 20 implantsinserted by conventional flapped surgical approach and study group which involved 20 implants inserted by flaplesssurgical approach. Estimation of alveolar bone was done for study group by bone (ridge) mapping procedure.Duration of surgical operation for each implant, Implant stability was measured at three time intervals (at surgery,two months and three months after surgery).Results: After three months interval of surgery the mean implant stability of the study (flapless) group achievedsignificant higher implant stability than control (flapped) group (P< 0.05) and the difference in measured implantstability was (5.05) implant stability quotient(ISQ). The time of surgical operation for implants in the study groupsignificantly was less than that of control group (P< 0.01).Conclusions: Implants placed with flapless surgical technique can produce high implant stability in shorter time andconsume prominently shorter time for surgical operation compared to those placed with conventional flappedtechnique


Article
Evaluation of the Effect of Implant-numbers, Position and Complete Over Denture on Alveolar Bone Resorption

Authors: Ali M. AlSheakh --- Nadira A Hatim
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2011 Volume: 11 Issue: SpIss Pages: S80-S92
Publisher: Mosul University جامعة الموصل

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Abstract

The aims: The aims of this study were to evaluate the alveolar bone resorption every 2.5mm distal to the implant over denture to the retromolar pad in the mandibular arch, and to the maxillary tuberosity in the maxillary arch in edentulous patient according to number between two and four, and position of implants between canine and 2nd premolar. Materials and Methods: Eight patients (age range 45-60 years) were selected from the department of Prosthodontics/ College of Dentistry/Mosul University, who had at least one edentulous arch. All patients complaining from poorly retention conventional acrylic complete denture due to the residual ridge resoption, but the alveolar ridge height need at least 10mm implant length.After completing the surgical steps of 26 implants (two or four implant screw type titanium), over denture type with one step surgery for all implant types were constructed in conventional method after one month healing period. The prosthesis was delivered to the patients after one months of making the period elapsed. Dentures were delivered without socket attachment(six months). For assessment of alveolar bone height, for each patient panoramic exposure of OPG was recorded – three times [base line(at time of placement) , 6 months and 12 months]. Results: Results of this study showed, that mean difference of bone resoption range between [-0.2 –(-0.6)mm], and there was a significant difference of bone resoption between base line and 12 months to p0.05 according to number and position of implants. Conclusions: The conclusion of this study showed that, there was no significant different of alveolar ridge bone resoption between implants number in two or four implants over denture or implant position


Article
Finite element stress analysis study for stresses around mandibular implant retained overdenture MIR-OD

Authors: Raghdaa K. Jassim رغداء جاسم --- Ibrahim K. Ibrahim
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 30-36
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: It has been well known that the success of mandibular implant- retained overdenture heavily dependson initial stability, retention and long term osseointegration this is might be due to optimal stresses distribution insurrounding bones. Types of mandibular implant- retained overdenture anchorage system and number of dentalimplants play an important role in stresses distribution at the implant-bone interface. It is necessary to keep thestresses below the physiologic tolerance level of the bone .since. And it is difficult to measure these stresses aroundbone in vivo. In the present study, finite element analysis used to study the stresses distribution around dental implantsupporting Mandible implant retained overdentureMaterials and methods: Eight models were constructed including four designs of anchorage system (ball-cup, ball-ORing, bar without distal extension and bar with distal extension).The first group of models were supported by fourdental implant and second group of models were supported by two dental implant only. Models constructed fromthe data obtained directly from patient The contour of bone was obtained from C.T scan image of patient, thendata transferred to ANSYS program for modeling then load applied and solve the equation by the program,Specified nodes were selected at the rings of crestal bone (cortical bone) and cortical cancellous interface aroundeach dental implant and fixed for all models to monitor the stress change in that regions of different design of MIROD..After load application, Specified nodes were selected at the rings of crestal bone (cortical bone) and corticalcancellous interface around each dental implant and fixed for all models to monitor the stress change in thatregions of different design of MIR-OD .Results: In the present study the stress distribution and maximum stresses value around dental implant had arelationship to the number of dental implant. , The result appeared that the maximum stresses and means of stressesvalue was lower in the first group of models (which was supported through the use four dental implant) than thesecond group of models (which was supported through the use of two dental implant only). For the first group ofmodels the maximum stresses value around mesial implant was11.67, 10.51, 10.98 and 10.72 Mpa, while the maximumstresses around distal implant was 21.33, 18.51, 18.86, and17.56 Mpa for models 1,2,3 and 4respectively ,and thestresses around implant supporting second group of models was 22.52, 22.16, 20.51 and 19.60 Mpa for models5,6,7and8 respectively .Statistical analyses of means value appeared that there was statistically significant differencein stresses means value around implant of the second group with that’s values around mesial and distal implantsupporting first group of model . Regarding the result of both ball and bar system, it has been demonstrated thatstress was greater with ball attachment and MIR-OD supported by the use of four dental implants and anchored bybar attachments with distal extension gives the minimum values of stresses than the rest models. Also the results showthat higher stresses value was appeared at the cortical bone ring surrounding dental implant especially the distalimplant nearest to the free end extension area. Also it was appeared that the best model was Mandible implantretainedoverdenture that’s anchored by bar with distal extension and support by four dental implant .Conclusions: Bar-clips with distal extension mode of attachment considered the best type in producing the leaststresses around dental implant regardless number of dental implant used

Keywords

Implant --- overdenture --- stresses --- bar --- ball


Article
The Effect Of Treatment Protocol and Implant Dimensions on Primary Stability Utilizing Resonance Frequency Analysis

Author: Thair Abdul Lateef ثائر عبد اللطيف
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2017 Volume: 29 Issue: 1 Pages: 111-116
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: According to Branemark’s protocol, the waiting period between tooth extraction and implant placement is 6–8 months; this is the late placement technique. Achieving and maintaining implant stability are prerequisites for a dental implant to be successful. Resonance Frequency Analysis (RFA) is a noninvasive diagnostic method that measures implant stability. The aim of this study was to investigate the influence of treatment protocol and implant dimensions on primary implant stability utilizing RFA.Materials and methods: This study included 63 Iraqi patients (37 male, 26 female; ranging 22-66 years). According to treatment protocol, the sample was divided into 2 groups; A (delayed) & B (immediate). Dental implants were inserted and the implant stability quotient (ISQ) measures for primary stability documented by Osstell device.Results: For both groups fixtures introduced in the mandible showed a higher stability (74 and 71.85) respectively and was lower in maxilla. The mean primary stability of group A was 70.21 (ranged from 51-83), while for group B was 68.55 (46.5-81).Conclusion: primary stability influencing osseointegration and subsequent long term success. It was higher in association with delayed implant placement, mandible, and increased implant diameters


Article
The Effect of Green Tea Polyphenol (EGCG) on Orthodontic Micro-Implant Stability: An experimental study

Authors: Mustafa Muath Hamed Al-Sultan --- Zaid Salim Twafeeq
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2017 Volume: 4 Issue: 2 Pages: 102-109
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

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Abstract

Background Increasing the orthodontic micro-implant stability and enhancing bone response around it, is a fundamental objective of successful therapy. Materials and Methods Thirty orthodontic micro-implants, 1.3 mm in width and 5 mm in length (Dentos, AbsoAnchor, South Korea), were used with three implants were inserted in the right tibias of ten New Zealand rabbits, the rabbits categories into two groups, fve each. The primary stability was measured once the implant inserted, using Periotest. The experimental group fed (0.5% wt/vol/day) Green Tea, using the loading technique, for four weeks interval. At the end of the experimental period, the rabbits were sacrifced, and the secondary stability measurement was taken. Results Using paired t-test, the results showed a signifcant increase in secondary stability for the experimental group after four weeks experimental period when compared with the primary one. While the control group showed a non-signifcant increase in the secondary stability compared with the primary one. Conclusion This study concluded that the Green Tea could enhance bone response around orthodontic micro-implant within four weeks healing period and consequently increase the stability of orthodontic micro-implant

Keywords

Green Tea --- Micro-Implant --- Stability


Article
Histological and histomorphometric studies of the effects of hyaluronic acid on osseointegration of titanium implant in rabbits

Authors: Mohammad Hasan Mohammad محمد حسن محمد --- Nada M. H. Al-Ghaban ندى الغبان
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2018 Volume: 30 Issue: 2 Pages: 10-16
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluronic acid gel). All sections have been stained with Haematoxylin and Eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (V*).Results: Histological findings for hyaluronic acid- coated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. Histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals.Conclusion: Commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration


Article
Intentional penetration of dental implants into the maxillary sinus: a retrospective study
الاختراق المتعمد لزراعة الأسنان في الجيب الفكي العلوي: دراسة بأثر رجعي

Author: Omed Ikram Shihab
Journal: Zanco Journal of Medical Sciences مجلة زانكو للعلوم الطبية ISSN: 19955588/19955596 Year: 2017 Volume: 21 Issue: 1 Pages: 1536-1539
Publisher: Hawler Medical Univeristy جامعة هولير الطبية

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Abstract

Background and objective: Perforation of the maxillary sinus by a dental implant isan issue of concern by many dental implant clinicians. This study aimed to assess thesuccess rate and consequences of dental implants emerging into the maxillary sinus.Methods: The maxillary sinus was intentionally perforated for dental implant placementin 35 patients with reduced posterior maxillary bone height (4 mm or more). A total of 70implants engaged bicortically and emerged into the sinus. Nineteen female and 16 malepatients were involved in the study. The patients were followed up for sinus complicationsand dental implant success.Results: From the total, only two implants were failed; one during gingival formerplacement and the other after loading by one year. No patient presented with sinusitisclinically and radiographically. Three patients developed epistaxis just on the day ofsurgery and became well after on.Conclusion: Within the limits of this study, dental implant emergence into healthymaxillary sinus is considered a safe and successful procedure.


Article
Osseointegration of dental implants without primary stability: an experimental study in sheep
Osseointegration من زراعة الأسنان دون الاستقرار الأولي: دراسة تجريبية في الأغنام

Authors: Ahmed A. Haider --- Othman A. Omer --- Hozak Zahir Ali --- Abduljaleel Azad Samad --- et al.
Journal: Zanco Journal of Medical Sciences مجلة زانكو للعلوم الطبية ISSN: 19955588/19955596 Year: 2017 Volume: 21 Issue: 1 Pages: 1616-1618
Publisher: Hawler Medical Univeristy جامعة هولير الطبية

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Abstract

Background and objective: Primary implant stability is considered necessary forachieving and maintaining osseointegration. This experimental study aimed to evaluate theoutcome of implants without primary stability, clinically and radiographically.Methods: Two adult sheep (3-4 years of age), 70 kg in weight, were included in the study.After sedation and local anesthesia, the lateral side of the basal bone of mandible isexposed by a single long incision. The implant bed performed in the inferior border of thebasal bone of mandible drilling to 5 mm in diameter and 10 mm in length. Five implantswere inserted into the basal bone of mandible for each side (right and left), but the sizes ofinserted implant was 3.8 mm in diameter and 10 mm in length, after 4 months the 2 sheepwere sacrificed and the universal torque ratchet was used to measure the stability of theimplant by a counter torque 30 N/cm test. Cone Beam Tomography (CBCT) was used toevaluate the implants radiographically.Results: Nineteen (from 20) implants successfully tolerated a 30 N/cm countertorque testcomprising (95%). Only one implant failed to osseointegrate (5%). During the healingperiod, no any adverse clinical signs reported.Conclusion: Dental implants may have a chance to osseointegrate even in the lack ofprimary stability.

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