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THE EFFECT OF SODIUM ALENDRONATE GEL ON OSSEOINTEGRATION OF SUBMERGED DENTAL IMPLANTS

Ahmed A. Hotieba, Ahmed A. Sharara, Saeeda M. Osman

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Introduction: A plenty of materials have been used to increase the success rate, decrease time needed for osseointegration, stimulate bone formation around dental implants. Bisphosphonates increase bone mineral density by inhibiting osteoclast-mediated bone resorption. Alendronate sodium hydrate is a bisphosphonate that potently inhibits bone resorption and is used to treat osteoporosis. A 1% sodium alendronate gel is manufactured and tested in order to accelerate osseointegration around dental implants. Objectives: This study aims to compare clinically and radiographically the osseointegration for 2 groups of submerged dental implants both in upper anterior and premolar region, first group with the use of local sodium alendronate gel prior to placement of dental implant and the second group without. Materials and methods: A clinical trial on 24 implants divided into 2 groups indicated for dental implant placement in the upper anterior and premolar region selected from the outpatient clinic of the Oral and Maxillofacial department, Faculty of Dentistry, Alexandria University. For the test group 12 implants were placed with sodium alendronate gel just prior to implant placement. For control group 12 implants were placed without sodium alendronate gel. Results: On the 12 week the resonance frequency analysis (RFA) median records were (55.50, 54.0) and the Mean ± SD (55.08 ± 4.94, 54.67 ± 5.69) for the control group and test group, respectively. The bisphosphonate-coated implants showed an increase in implant stability from 0 to 12 weeks more than the control\'s measures. On the 12 week, the mean peri-implant bone density value was 1417.92 ± 310.54 for control group and 1550.25 ± 286.15 for test group. These increases in the bone density were higher in test group than the control group. Conclusions: Using sodium alendronate gel with delayed implant placement could enhance the osseointegration around dental implants. Keywords: Sodium Alendronate gel, osseointegration, cone beam CT, implants stability, bone density.


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EVALUATION OF DENTAL IMPLANTS IN MANDIBULAR NARROW RIDGES USING BONE EXPANSION AND BENDING TECHNIQUE

Alaa A. Heggy, Ahmed M. Shaaban, Riham M. El-Dibany

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Introduction: Narrow dentoalveolar ridges remain a challenge for the successful placement of implants; success depends largely on the quality and quantity of the available bone in the recipient site. This however may be compromised or unavailable which necessitates the need to manipulate the residual bone by contouring or making dimensional changes to create an intra-bony cavity to form a receptor site for an implant while preserving bone integrity and viability. Objectives: Evaluation of the success of dental implants in mandibular narrow ridges (≤ 5mm) after using bone expansion and cortical bone bending technique with a new design of bone expander. Materials and methods: This clinical study was performed on a total of eight patients with mandibular narrow ridges (≤ 5mm). All implants were followed for 6 months. Clinically, each patient was evaluated for pain, tenderness or discomfort, presence of swelling or infection and mobility of the implant. Also, radiographic investigations were performed for the assessment of marginal bone level, bone width and the bone density around the implant. An implant stability and assessment of the osseointegration progress evaluation was conducted using the resonance frequency analysis technique (Osstell) immediately after implant placement and after three months and after six months. Results: There was a statistically significant increase in the bone density around the implants throughout the evaluation period and there was increase in implant stability quotient after six months was statistically significant (p=0.008). There were significant decreases in the mean of marginal bone level changes by time in all cases, the increase in bone width quotient after six months was statistically significant p<0.001. Conclusions: using the newly designed star shape bone expanders as a bone expansion and bending technique, showed an adequate clinical and radiographic performance in the mandibular narrow ridges. Keywords: narrow ridges, bone expansion, implant stability.


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EVALUATION OF BASAL DENTAL IMPLANTS IN EDENTULOUS POSTERIOR MAXILLARY REGION

Ayman E. Gaber, Riham M. Eldibany, Gaafar N. El-Halawani

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Introduction: Tooth replacement with dental implants has proven to be a reliable and effective means of restoring the dentition. The use of implant   can conserve sound tooth by reducing the need to prepare adjacent teeth as abutment. Owing to mechanical and anatomic difficulties, implant treatment in the posterior maxilla represents a challenge due to several factors such as: type of bone, bone density and pneumatization of maxillary sinus. Objectives: to evaluate the delayed placement of basal dental implants in the posterior maxillary region. Materials and methods: The research conducted on 14 patients with missing maxillary posterior teeth. Panoramic x-ray together with Cone Beam Computed Tomography (CBCT) were done preoperatively before placement of the basal dental implants. Stability of the implants were measured by periotest immediately, 1 month postoperatively and 3months postoperatively and CBCT were done immediately following implants insertion and after 3 months. Results: There was a statistically significant increase in the implant stability readings using periotest at one month and 3 months postoperatively and The mean bone density showed a statistically significant difference between immediate postoperative and at 3month Conclusions: The use of Basal dental implants in atrophic posterior maxilla provides clinicians with a more conservative option of the treatment and help to minimize treatment duration, cost and trauma. Keywords: Dental implants, stability, maxillary posterior region, basal implants.


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EFFECT OF FLUORIDE INCORPORATION IN BLEACHING AGENTS ON ENAMEL

Doha M. El-Sayed, Afaf A. El-Sawa, Sahar S. karam

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Introduction: Tooth bleaching has proven to be a conservative esthetic solution for tooth discoloration, hydrogen peroxide (HP) is used as an active oxidizing agent for tooth whitening; it can be used either directly or indirectly by chemical reaction from carbamide peroxide (CP). So many patients suffer from discomfort and sensitivity during and after the bleaching procedure. The use of fluoride shows to be beneficial in reducing the adverse effects of bleaching on Enamel. Objectives: The study was designed to evaluate the effect of fluoride incorporation in bleaching agents on enamel surface properties. Materials and methods: twenty sound human premolars extracted for orthodontic reasons were selected for the study. The selected premolars were randomly divided into 2 equal groups (10 teeth per group) as follows: Study Group I: The teeth were bleached using 10% Carbamide peroxide. Study Group II: The teeth were bleached using 10% CP containing 0.11% fluoride. All the specimens were examined by scanning electron microscopy (SEM) and micro-hardness test. Results: after 14 days erosion pattern was noted in teeth from group 1 while the teeth of group 2 showed milder demineralization, group 1 showed significant decrease in micro-hardness compared to the base line whereas group 2 teeth that were treated with fluoridated bleaching agent showed insignificant reduction in micro-hardness. Conclusions: incorporation of fluoride in bleaching agents reduces the adverse effects of bleaching on the enamel surface. Keywords: bleaching, fluoride, enamel, carbamide peroxide, demineralization.


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SCANINING ELECTRON MICROSCOPIC EVALUATION OF CHITOSAN NANOHYDROXYAPATITE SCAFFOLD FOR SOCKET HEALING IN RABBITS WITH INDUCED OSTEOPOROSIS

Hagar S. Gharib MSc, Afaf A. El-Sawa, Sahar S. Karam, Sara A. Hamza

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Introduction: Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone.  In the present study, Chitosan– nanohydroxyapatite (CS/nHA) scaffolds have been developed as bone graft substitutes in rabbits with induced osteoporosis. Objectives: To evaluate the effect of Chitosan- nanohydroxyapatite (CS/nHA) scaffold in bone tissue regeneration of extracted socket in rabbits with induced osteoporosis; using Scanning Electron Microscope and Energy Dispersive x-ray analysis [EDXA]. Materials and methods: Twenty NewZealand white female rabbits were randomly divided into 2 equal groups; group A (osteoporosis) with no graft material, and group B (osteoporosis with CS/nHA). After the experimental period the animals were sacrificed at 2 & 4 weeks. The effect of CS/Nha was evaluated using Scanning Electron Microscope and Energy Dispersed x-ray analysis [EDXA]. The data obtained was tabulated and subjected to statistical analysis. Results: Scanning Electron Microscopic results revealed more trabecular bone thickness with regular bone surface, and uniform osteocyte lacunae in the group B (osteoporosis with CS/nHA) than group A (osteoporosis), and these results were proved by  EDXA which showed more Ca and P ratio in the group B than group A. Conclusions: CS/nHA scaffold is considered an effective hard tissue engineering material with sufficient interconnected porosity and mechanical strength to allow cell adhesion, migration, growth and proliferation resulting in good integration  with  surrounding  tissues, and rapid bone healing, thus it might be used in osteoporotic condition. Keywords: Osteoporosis, Extraction, Chitosan, Nanohydroxyapatite, Scaffold, Bone.


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THE EFFECT OF AMOXICILLIN ON THE SECRETORY STAGE OF AMELOGENESIS IN RATS

Hossam M. Mostafa, Fathy I. Shehata, Samia S. Omar, Khadiga Y. Kawana

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Introduction: Molar–incisor hypomineralization is a developmental enamel defect affecting first permanent molars and incisors. The intake of antibiotics during pregnancy and early childhood has been associated with molar incisor hypomineralization. Objectives: Was to determine the effect of amoxicillin on the secretory a stage of amelogenesis histologically and histomorphometrically. Materials and methods: Fourteen pregnant rats were randomly assigned to two groups that received physiological solution (control group), 250 mg/kg/day amoxicillin (study group). Directly after birth, fourteen pups representing each group received the same treatment with dose equivalent to their body weight then they were euthanized at day 7 birth. The ameloblasts of developing molars were examined histologically and histomorphometrically. Results: In day 7 after birth, the ameloblasts in control group revealed normal features of amelogenesis while in study group, numerous vacuolar like structures were seen in between secretory ameloblasts. Conclusions: Amoxicillin disrupts the normal structure of enamel and impairs the secretion of enamel matrix Keywords: Ameloblast, amoxicillin, secretory, amelogenesis


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COMPARISON OF BONE HEALING AFTER THE USE OF A THREE DIMENSIONAL MINIPLATE AND A CONVENTIONAL MINIPLATE IN MANDIBULAR BODY OSTEOTOMY (AN EXPERIMENTAL STUDY)

Mohamed M. Elrewany, Ragab S. Hassan, Ziad T. Mahmoud, Dina A. Nagui

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Introduction: Mandibular fractures comprise most of the traumatic injuries treated by an oral and maxillofacial surgeon. The aim of fracture treatment is to restore the architecture and function of bone.  Many techniques for treating mandibular fractures have evolved over the years. The design of the three dimensional (3D) plate is conceptually that of 2 linear plates connected by reinforcing vertical struts providing greater resistance against gap opening at the inferior border with biting forces. Objectives: To compare histologically bone healing of mandibular body osteotomy after using either a 3D miniplate or conventional miniplates. Materials and methods: This study was conducted on twelve healthy dogs. An iatrogenic osteotomy defect was performed intra-orally between the mandibular 3rd and 4th premolars using a surgical micro reciprocating saw. The fragments will be reduced bimanually and stabilized: Group A (six dogs): 3D miniplates. Group B (six dogs): conventional miniplates. The dogs were euthanized at 2 and 6 weeks postoperatively and the osteotomy sites were excised, divided into three thirds (Tension Third, TT; Intermediary Third, IT; Compression Third, CT) and prepared for histological analysis. Results: The osteotomy site was completely filled with parallel-fibred bone, with more newly formed Haversian systems in Group A compared with Group B, bone repair did not reach the typical aspects of the parent lamellar bone. The percentages of newly formed bone at 2 weeks in group A according to thirds (TT, IT and CT) that reported have a statistically significant difference in comparison with group B. At 6 weeks, there were no statistically significant differences between the two groups among the TT and CT but there was a statistically significant difference (p4 = 0.039) in the IT. Conclusions: 3-D plates could be a better option than conventional miniplates. Keywords: Mandibular fracture, 3-D plates, osteosynthesis, conventional miniplates.


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EVALUATION OF BASAL DENTAL IMPLANTS IN POSTERIOR MANDIBLE

Mostafa M. Omar, Riham M. Eldibany, Lydia N. Melek

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Introduction: Dental implants provide a unique treatment modality for the replacement of a lost dentition. Objectives: The aim of this study was to evaluate the placement of newly designed basal dental implant in the posterior mandible. Materials and methods: This clinical study was conducted on 15 basal dental implants placed in 8 patients having missing lower posterior teeth. The patients were followed up clinically daily for the first week then weekly for the first month postoperatively regarding pain, edema and any post-operative complications. Radiographic evaluation was performed by cone beam computed tomography (CBCT) preoperatively, immediately and 3 months postoperatively. Periotest was used to determine implant stability immediately and 3 months postoperatively. Results: All the results were evaluated clinically, radioghraphically and statistically. Clinically, mild pain and edema occurred and subside 1 to 4 days post-operatively without post-operative complication. Radiographically bone density has shown significant increase immediately post-operatively. Conclusions: The sharp threads of Roott basal dental implants allowed good bone anchorage and high primary stability which is one of the main factors of implants success. Keywords: Basal dental implant, periotest, osseointegration.


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RECONSTRUCTION OF THE ORBITAL SKELETON USING COMPUTER- AIDED INDIVIDUALIZED TITANIUM MESH COMPARED TO CONVENTIONAL TITANIUM MESH

Omaima M. Saqr1* MSc, Ahmed R. Kotb, Ahmed S. EL-Mahallawy, Riham M. El Dibany, Mahmoud H. Moursy

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Introduction: Orbital reconstruction is one of the most challenging tasks for the surgeon who treats craniofacial trauma. Suboptimal outcomes may lead to debilitating morbidity with significant emotional, functional, and occupational deficits Objectives: This study was designed to compare the efficacy of the computer-aided fabricated individual titanium mesh and conventional titanium mesh in orbital skeleton reconstruction in cases of infraorbital dysesthesia. Materials and methods: The study population included 20 patients with orbital skeleton fractures. The sample was selected conveniently to fulfill a list of inclusion criteria. The selected participants were randomly allocated into two equal groups, each group included 10 patients. In the course of a surgical treatment, individually designed titanium mesh were manufactured by application of computer- aided design in combination with rapid prototyping technologies (CAD/RP). Preoperative analysis and postoperative monitoring were conducted to evaluate their success based on restoration of infraorbital nerve function that was evaluated by pin prick test and electrical pulp testing. Results: Regarding postoperative clinical evaluation, group 1(study group) was superior to that of group 2 (control group) in restoring the function of infraorbital nerve Conclusions: computer aided titanium mesh was an accurate option in reconstructions of traumatic orbital wall fractures. Keywords: Computer aided titanium mesh, Prefabricated titanium mesh, 3D printing.


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EVALUATION OF DENTAL IMPLANTS USING A MODIFIED THREAD GEOMETRY IN THE MANDIBULAR PREMOLAR REGION

Rana M. Kamel, Samraa A. El Sheikh, Hala R. Ragab

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IntroductioN: Modern implantology is changing direction towards the development of new implant macrodesigns that are able to provide a high level of physico-mechanical characteristics. This study examines the mechanical aspect of implants. In particular, macrodesign such as thread shape, pitch and depth. ObjectiveS: To evaluate clinically and radiographically fin thread design implant osseointegration and primary stability in mandibular premolar region. Materials and methodS: A clinical study was conducted on thirteen patients with missing mandibular premolar teeth. The magic fc implants with fin thread were inserted. After 3 months, final crowns were delivered. All implants were followed for 6 months. Clinically, each patient was evaluated for pain, swelling and stability of the implant. Radiographically, cone beam computed tomography (CBCT) was used for the assessment of marginal bone level and bone density. ResultS: There was a significant increase in bone density from immediate postoperative to the end of the 6 months. The mean of marginal bone level from immediately post-operative to the 3rd month was significant and from immediate to 6th month was significant. One case displayed swelling in the first week and the implant was removed (failure case) due to lack of oral hygiene maintenance by the patient. ConclusionS: Magic FC implants with fin thread were a successful treatment procedure, with satisfactory clinical outcomes, and a low incidence of complications. KeywordS: fin threads, primary stability, osseointegration.


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EFFECT OF LOW-LEVEL LASER THERAPY ON ORTHODONTIC INDUCED INFLAMATORY ROOT RESORPTION IN RATS

Ahmed M. Yassin, Fathy I. Shehata, Afaf A. Al-Sawa, Sahar S. karam

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IntroductioN: Low-level laser therapy (LLLT) has been studied in many fields of dentistry due to its reparative and anti-inflammatory effect. Regarding the orthodontic tooth movement, LLLT accelerates tooth movement, reduces the pain, enhances bone remodeling and reduces the orthodontic inflammatory induced root resorption (OIIRR). ObjectiveS: The aim of the present study was to assess histologically and histomorphometrically the effect of LLLT on OIIRR under heavy orthodontic force magnitude (50 g) in rat model. Materials and methodS: Sixteen male Albino rats weighing from (250-300 g) were randomly assigned to two equal groups (8 rats each). Control heavy-force group (CH): the maxillary right first molars were subjected to orthodontic force of 50 g by placement of a coil spring. Laser high-force group (LH): the maxillary right first molars were subjected to orthodontic force of 50 g + LLLT at four points (two buccal and two palatal), 12 seconds per point, with a GaAlAs diode laser source irradiated with the dose of 4.8 J/cm2 (100 mW, 12 s, 0.6 J) on every other day during force application. The rats were sacrificed after 21 days of orthodontic force application. After sacrificing the rats; the maxillae were hemisected and serial sections of the area of maxillary right first molar were obtained and evaluated histologically and histomorphometrically. ResultS: Root resorption was significantly decreased (p=0.001) in laser group (L) in comparison to the control group (C). In contrast, root resorption was the largest and deepest up to the dentin in the control group. Moreover, odontoclasts were observed especially in the C group indicating still active root resorption activities. In addition, increased blood vasculature and formation of reparative cementum layer covering the resorption lacunae were observed in the Laser group.  


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DIGITAL EVALUATION OF DIMENSIONAL ACCURACY AND INTIMACY OF FIT OF SINGLE-PIECE CLOSED HOLLOW BULB OBTURATORS FABRICATED BY CAD/CAM ADDITIVE MANUFACTURING

Akram F. Neena, Ahmed M. Alshimy, Mohamed M. Khamis, Amr M. Ekram

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Introduction: Conventional techniques for closed hollow bulb obturators construction are technique sensitive, consume considerable amount of materials, and lack adequate control of the walls thickness of the bulb. Additionally, created sealing area is a potential site of leakage and discoloration. Digital technologies offer promising solutions to these drawbacks. Subtractive manufacturing systems are unable to produce hollow objects as one piece. In contrast, additive manufacturing systems can produce a hollow object in one piece. Objectives: The aim of the present study was to evaluate one-piece closed hollow bulb obturators fabricated using CAD/CAM additive manufacturing and compare them to those constructed from heat cured resin. Materials and methods: Six partially dentate patients with healed unilateral maxillary defects (Aramany’s classes I or II) received two closed hollow bulb obturators. One constructed using CAD/CAM additive manufacturing, and another constructed from conventional acrylic resin. All patients’ prostheses were evaluated for dimensional accuracy and intimacy of fit using digital measuring software package. Results: CAD/CAM obturators showed negative dimensional change values when compared to the original design, while Heat-cured obturators showed positive ones. Generally, the highest values of deviations were recorded at occlusal units for CAD/CAM obturators (-0.34 ± 0.10) and Heat-cured obturators (0.21 ± 0.12) when fitting surface was used as reference. There were statistical significant differences in dimensional deviation between both obturator groups using two registration references. CAD/CAM obturators showed lower misfit values when compared to Heat-cured ones. The highest values of misfit were recorded at the oral extensions of the CAD/CAM (0.44 ± 0.27) and Heat-cured obturators (0.47 ± 0.32). However, there were no statistical significant differences between both obturator groups at any measured surface. Conclusions: Additive manufacturing of obturators could be an alternative to conventional techniques for direct construction of one-piece closed hollow bulb obturators.  


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A COMPARATIVE STUDY TO EVALUATE THE RETENTION OF CONVENTIONAL AND CAD/CAM FABRICATED BAR ATTACHMENT IMPLANT SUPPORTED ASSEMBLY (IN VITRO STUDY)

Aly A. Abdelrehim, Ahmed A. Abdelhakim, Sherif M. ElDakkak, Mohamed A. Gepreel

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Introduction: The use of implant-supported overdentures is a common approach for treating edentulous mandibles. Retention and stability are provided through attachments; bar attachments being probably the most retentive due to greater mechanical stability and better wear resistance. Micro and macro movement between the retentive surfaces of an attachment during mastication, insertion and removal will lead to wear and decrease of the retentive capacity. Using CAD/CAM technology should produce more precise frameworks with better retention. Objectives: was to compare the retention of different Cobalt Chromium bar attachments fabricated by CAD/CAM technology and conventional methods. Materials and methods: Two bar attachments of different method of fabrication were studied. The bars were divided into two different groups according to whether the bar was fabricated using the conventional method or CAD/CAM technology. The retention provided by each bar was tested using Universal testing machine. The difference in retention was compared between the groups. Results: Data was collected, tabulated and statistically analyzed using the appropriate test. Group 1 needed 32.91N dislodging force. Group 2 needed 62.8N to separate the clip from the bar Conclusions: CAD/CAM fabricated bars showed a significantly higher retentive force in comparison to conventional bars. Keywords: Bar attachments, Overdentures, CAD/CAM, Cobalt Chromium, Implants


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EVALUATION OF STRAIN DEVELOPED AROUND SHORT DENTAL IMPLANTS USING TWO DIFFERENT RESTORATIVE MATERIALS (IN VITROSTUDY)

Eman A Ibrahim, Ahlam Elsharkawy, Mohamed S Nassif, Nermeen A Rady

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Introduction: The use of short implants has been introduced as an alternative treatment for posterior regions, however, it leads to serious prosthetic complications. Using CAD/CAM, materials like zirconia and Bio-HPP can be used to fabricate implant supported restorations. Objectives: This study aimed to evaluate and compare the strains developed around short and standard implant length using two different crown materials. Materials and methods: Polyurethane blocks (n=20) were used as alternative materials for human cancellous bone. Blocks were divided into two groups, group A received ten standard length implants 12 mm, and group B received ten short implants 7 mm. Each group was equally subdivided into two subgroups, according to crown material (BioHPP and zirconia). Universal testing machine was used to apply a load of 100 N axially and obliquely at 45° on the restorations. Microstrains were measured using strain meter. Results: The difference in microstrain values between BioHPP and zirconia was statistically insignificant for both group A and group B. Comparing between group A and group B having the same restorative materials, it was found that, the difference was statistically significant for zirconia in axial loading only. A significant difference was observed between oblique and axial loads in standard implant length for both BioHPP and zirconia restorations, and for zirconia in short implants as well (p value=0.043), while the difference was insignificant for BioHPP in short implants. Conclusions: Short implants are comparable treatment modality to standard implant lengths for single tooth restoration. Oblique forces produce more stresses than vertical forces. According to the average of loads, there is no significant difference between BioHPP and zirconia for both short and standard implant length. However, it is advisable not to use zirconia restorations with short implants. Keywords: Short implants, Crown/implant ratio, CAD/CAM, Zirconia, High Performance Polymer, Strain gauge.


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EXPRESSION OF TLR7 IN ORAL SQUAMOUS CELL CARCINOMA AND ITS CORRELATION WITH LYMPH NODE METASTASIS (AN IMMUNO-HISTOCHEMICAL STUDY)

Engy A. Youssef1 MSc, Hanaa S. Raslan2 PhD, Sahar M. El-Sheikh2 PhD, Sahar E. Riad2 PhD, Radwa A. Mehanna3 PhD Marwa M. Afifi4 PhD

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Introduction: Oral squamous cell carcinoma (OSCC) accounts for most of oral cancers which is about (90%) of all types. OSCC is an important cause of morbidity and mortality worldwide. Early detection; diagnosis and early treatment are still the key points for OSCC patients to improve survival rate and quality of life. Toll like receptors (TLRs), through their role in innate immunity, have been implicated in the pathogenesis of several diseases, including cancer and OSCC is one of these cancers. Nodal metastasis is playing a key role in detecting the prognosis and the outcome. TLR7 is one of the TLRS which is expressed in OSCC, the correlation between the expression of this receptor and the presence of nodal metastasis has been assessed and evaluated as TLR7 may be of great significance in tumors metastasis so can help in prognosis and aid in treatment modalities. Objectives: The aim of the present study was to evaluate the expression of TLR7 in the specimens of primary tumor tissues of OSCC and correlate it with the lymph node involvement. Materials and methods: TLR7expression was studied in 50 OSCC cases. The specimens were taken from the primary tumor of 25 cases with positively involved lymph nodes and another 25 cases with negatively involved lymph nodes and 10 normal mucosal tissues taken from OSCC patients and healthy individuals. Immuno-histochemical (IHC) staining was performed using the Labeled Strept-Avidin Biotin complex method (LSAB), using the anti-TLR7 antibody. Results: TLR7 showed high expression in OSCC cases with positive lymph node metastasis than those with negative lymph node metastasis. Conclusions: TLR7 expression could be a guiding tool used to detect prognosis in OSCC patients and as an indicator for metastasis. Keywords: Oral squamous cell carcinoma, lymph node metastasis, TLR7, Immunohistochemistry.


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EFFECT OF COMPOSITE PREHEATING AND PLACEMENT TECHNIQUES ON MARGINAL INTEGRITY OF CLASS V RESTORATIONS

Mohamed N. Moustafa, Wegdan M. Abd El-Fattah, Fayza H. Al-Abbassy

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Introduction: Different placement techniques of resin-based composite (RBC) systems have been developed to improve the marginal adaptation and reduce microleakage. These techniques included preheating and vibration of resin composite materials. Objectives: The current study aimed to investigate the effect of preheating and placement techniques on microleakage and marginal gap formation of class V composite restorations. Materials and methods: A total of eighty sound extracted human molars were used in this study. Standard class V cavities were prepared on their buccal surfaces (4mm mesiodistally, 3mm occlusocervically, and 3 mm pulpal depth). The teeth were divided into 4 groups (n=20): Group I: restored with Filtek bulk fill flowable composite, Group II: restored with Filtek bulk fill composite after it was heated to 60°C using Calset device, Group III: restored with Filtek bulk fill composite adapted with a vibrating instrument (Compothixo), Group IV: restored with Filtek Z350 XT. Specimens were light cured, thermocycled between (5 ºC and 55 ºC in water) and marginal gaps assessment was measured under a stereomicroscope and measured in micrometers. Then teeth were dyed with 0.5% basic fuchsin dye for 24 hours. The dyed specimens were sectioned in the buccolingual direction and evaluated for microleakage (dye penetration) using a stereomicroscope. Results: For marginal gap assessment, results revealed a significant difference between the tested groups, where flowable bulk‑fill showed the lowest statistically significant marginal gaps compared to other groups at the occlusal and gingival margins (p<0.05). For the microleakage test, the groups showed more microleakage at gingival margins compared to occlusal margins, flowable bulk- fill and preheated bulk -fill showed the lower microleakage scores among groups. Conclusions: None of the placement techniques produced gap-free margins. Flowable bulk-fill composite and preheated composite preserved better marginal integrity and reduced microleakage. Keywords: Dental Composite, Preheating, Microleakage, Vibration, Marginal gap.


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COLOR STABILITY AND SURFACE ROUGHNESS OF AN ORGANICALLY MODIFIED CERAMIC (ORMOCER) AND A METHACRYLAT BASED COMPOSITE RESINS (AN IN-VITRO STUDY)

Ramy M. Sherif, Wegdan M. Abd El-Fattah, Rania R. Afifi

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Objectives: The aim of this invitro study is to evaluate the color stability, change in opacity and change in surface roughness of an ORMOCER, and two methacrylate based composites after being immersed in different staining solutions with different time intervals. Materials and methods: A total of one hundred twenty disc specimens (10mm in diameter and 2mm in thickness) were prepared from three composite resins, A bulk fill ORMOCER based (Admira fusion X-tra) and a bulk fill methacrylate based (X-tra fill) and an incremental fill methacrylate based (Esthet-X HD) composite resins (n = 40). Specimens of each type were divided in to four groups according to immersion solutions (n = 10). Group A= Specimens were immersed in coffee (Nescafe classic, Nestle, Egypt), Group B= Specimen were immersed in tea (Lipton yellow lable, Unilever brand, Egypt), Group C = Specimen were immersed in cola (Coca cola company, Egypt) and Group D= Specimen were immersed in distilled water as a control group. Color evaluation was done at base line before staining and then at periods of 7 days, 14 days, 28 days using spectrophotometer. Change in color (∆E*) and opacity (∆Op) were obtained using the CIE L*a*b* system. Surface roughness was evaluated using Atomic Force microscopy at baseline before staining and then at 28 days from immersion in staining solutions. Results: All composite used showed change in color values at the end of the time intervals after 28 days of immersion in staining solutions. Group A (coffee) was the highest effecting group (ΔE >3.3) and Admira fusion X tra was the material with the highest change in color. Surface roughness also increased especially in group C (cola) for all materials after 28 days with no statistically significant difference between groups (p>0.05).  


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EVALUATION OF IMPLANT-ASSISTED MANDIBULAR OVERDENTURE WITH NEW METAL TO METAL INTERFACE ATTACHMENT SYSTEM (IN VITRO STUDY)

Rania E. Ramadan, Faten S. Mohamed, Mohamed A Gepreel

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Introduction: A well-constructed two-implant-assisted mandibular overdenture can be a successful treatment option for completely edentulous patients as it helps improving the oral function and patient satisfaction through elimination of the fear of dislodgment during speech or mastication. Various attachment systems can be used for retaining mandibular overdentures such as bar, ball and socket, OT equator and locators. A new attachment system with metal to metal interface named Titach has evolved. During mastication, loads are transferred to alveolar bone surrounding the implants. Objectives: This study was done to compare the stress transmitted to peri-implant tissues of implant-assisted mandibular overdenture using two different attachment designs; Titach attachment and locator attachment. Materials and methods: A completely edentulous epoxy resin mandibular model was used in which two parallel dental implants were inserted at the canine region bilaterally. Sixteen mandibular implant-assisted overdentures were constructed forming two groups; each with different attachment design. Group I received 8 pairs of Titach attachment, while group II received 8 pairs of locator attachment. The difference in stress distribution was measured using strain gauges and compared between the two studied groups. Vertical load and oblique load (30o and 45o) of 50 and 100 N using the universal testing machine were applied bilaterally on the central occlusal fossae of mandibular first molars. Results: There was no significant difference between group I and II upon application of vertical loading 50, 100N and 30o oblique loading 50 N. However, group I showed lower strain values upon application of 30o oblique loading 100N, 45o oblique loading 50N and 100N. Conclusions: Titach attachment with metal to metal interface showed less strain values with favourable stress distribution when compared to zest anchor locator attachment with nylon interface for implant-assisted mandibular overdenture. Keywords: implant-assisted overdenture, locator, Titach, strain gauges


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THE EFFECT OF IMPLANT LOCATIONS ON THE STRESS TRANSMITTED TO IMPLANT-TOOTH-ASSISTED PARTIAL OVERDENTURE (IN VITRO STUDY)

Tahany M. Kadeeb, Sherif M. El Dakkak, Moustafa Abo Shelib, Ahmed A. Abdel Hakim

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  Objectives: To evaluate and compare the effect of implant locations on the retention of the prostheses of implant tooth assisted partial overdenture for mandibular Kennedy class II with implant located in first premolar area and second molar area. Second objective was to evaluate the wear of female parts of the attachments attached to these implants. Materials and methods: The study was conducted on two parallel groups according to the different implant locations: Group (A) implant in first premolar area, Group (B) implant in second molar area. Two acrylic models with Kennedy class II were used in this study. Two implants with (2.3mm length and 3.6mm width), two positioner attachments were attached to implants and inserted in the previous locations for both groups. Each group had 9 sets of attachments with 3 different colored plastic matrices (27 matrices) with different retention force.  A metallic overdenture with acrylic resin base and teeth was constructed for each group. By using the universal testing machine, vertical load dislodgment forces were measured at anterior of the saddle of the denture and posterior of the saddle of the denture for both groups at the beginning of the study (initial retention) and after 50,000 cyclic with load of 20 K at first molar area, the retention test was repeated and the mean value was recorded. All retention parts were imaged under stereomicroscope to study wear and attrition of internal components. Results: In vertical dislodging, Group (B) posterior of the saddle, recorded the highest retention force. In Group (B) anterior of the saddle recorded the lowest retention force. After 50,000 cyclic loading, Group (B) posterior of the saddle was higher than Group (A) in retention force. Dimensional changes and wear scratches appeared in the metal housing and plastic matrices in central and outer lines.    


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ACCURACY OF GUIDED IMPLANT INSERTION IN MANDIBULAR FREE-END SADDLE AREAS USING STEREOLITHOGRAPHIC SURGICAL STENT

Waleed M. Abd Alkader, Magued H. Fahmy, Adham A. ElAshwah

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Introduction: The success of implant therapy depends primarily on appropriate treatment planning and properly performed implant placement surgery.Guided implant surgery (template based guided cavity preparation and guided implant insertion) is effective to guide the implant placement.This can be achieved by means of a surgical guide Stent.Stents are designed in conventional methods or stereolithography which allows the fabrication of surgical guides from 3D computer generated models for precise placement of the implants. Objectives: Assess the accuracy of stereolithographic surgical stent to orientate implant insertion in mandibular free-end saddle areas. Materials and methods: A total of 12 implants will be placed in patients having mandibular free end- saddle areas selected from the outpatient section of the department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Alexandria University, after virtual implant planning with implant studio software, the implants will be inserted using stereolithographical  design of surgical stent then measuring the deviation between the planned implant position before the surgery and the actual position of placed implant after surgical procedure. Results: Evaluation of the accuracy of placement was done by measuring the overall deviations between virtually planned and surgically placed dental implants.The mean of total angular difference in implant with stereolithographic stent were 10.9 ± 9.4°.While The Mean of total coronal differences in stereolithographic guided implant were 0.96 mm ± 0.7 mm.The Mean of total apical differences in stereolithographic guided implant were 1.8 ± 1.3 mm Conclusions: The stereolithographic surgical template was sufficiently accurate in transferring the planned implant position to the surgical field relative to the implant angulation and point of entrance. Keywords: Implant studio, stereolithography, guided implant surgery, surgical Stents.


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