Current Issue : July - September Volume : 2012 Issue Number : 3 Articles : 8 Articles
water solubility of new sealers should be studied. This study aimed to assess the water solubility\r\nof five root canal sealers (AH-26, Topseal, 2-Seal, Acroseal, and Roeko Seal Automix [RSA]).\r\nMaterials and Methods: In this in vitro experimental study, 30 specimens were fabricated from\r\neach of the abovementioned sealants. Then they were weighed and randomly divided into three\r\nsubgroups of 10 each (A, B, and C). They were set at 37�°C and 100% RH, in accordance with ANSI/\r\nADA 57 and ISO 6876-2001 requirements. Afterward, the specimens in subgroups A were incubated\r\nat 37�°C and 100% RH for 24 hours, while the specimens in the subgroups B and C were incubated\r\nin the same conditions for 7 days and 28 days, respectively. After incubation, the specimens were\r\ndried with blotting paper and were incubated for 24 hours at 37�°C and 0% RH. Then they were\r\nweighed. The percentage of weight loss was regarded as water solubility.\r\nResults: The mean solubility of the sealers AH-26, Acroseal, Topseal, 2-Seal, and RSA were 0.28%,\r\n0.36%, 0.07%, 0.037%, and 0.141% after 24 hours, respectively. After 28 days, their solubility were\r\n1.75%, 0.746%, 0.082%, 0.04%, and 0.517%, respectively. Only the solubility of the sealers 2-Seal\r\nand Topseal were not statistically different (P>0.3 [Tukeyâ��s]). Again only the solubility of 2-Seal and\r\nTopseal did not significantly increase between the 7th day and the 28th day of incubation (P>0.6\r\n[paired-samples t]).\r\nConclusion: All tested materials met the standards (maximum weight loss of 3% within 24 hours).\r\nHowever, the results of 2-Seal followed by Topseal were the most favorable ones....
Background: Investigation was designed to evaluate the behavioral changes in children receiving\r\ndental treatment while they have been administered combination of Midazolam/Ketamine or\r\nMidazolam/Promethazine.\r\nMaterials and Methods: This was a randomized double blind clinical trial with cases being selected\r\nfrom those uncooperative children aged 2 to 6 years from those referred for treatment under\r\ngeneral anesthesia. Anxiety score of all cases were recorded before any attempt using Frankel�s\r\nanxiety scoring system with those in negative category being included. Cases with at least a pair of\r\nsimilar size cavities on similar teeth were selected with each tooth being randomly allocated for one\r\nsedative regimen group. To avoid sequence effect, half of the patients received one regimen at the\r\nfirst visit while the other half received the other regimen as the first. Each case served as control\r\nfor him or herself to reduce influencing factors. Child�s reaction was recorded before, during, and\r\nat the end of dental procedure. SO2 as well as Pulse rate were recorded as the most critical vital\r\nsigns. Collected data were then analyzed using analysis of variance (ANOVA) and paired t-test.\r\nResults: Patients� mean age was 3.5 years with 43% being male. Only 10% of the Ketamine/Midazolam\r\ngroup showed considerable amount of change in their behavior with a statistical significant difference\r\nbeing presented (P=0.029).\r\nConclusion: Under the current circumstances, Ketamine/Midazolam combination provided\r\nsufficient sedative effect in lower doses. However, Midazolam/Promethazine combination did not\r\nproduce similar results....
enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation\r\non the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption.\r\nMaterials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated\r\nas an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA) (CenoBone�®)\r\nwas used as the graft material. The defects were made by the extraction of 3rd premolar. On one\r\nside of each jaw, the defects were preserved by DFDBA and defects of the other side left opened\r\nas the control group. Simultaneously the teeth adjacent to the defects were pulled together by\r\na NiTi coil spring. After eight weeks, the amount of (OTM), alveolar height, and root resorption\r\nwere measured. Analysis of variance was used for purpose of comparison.\r\nResults: There was a slight increase in OTM at grafted sites as they were compared to the control\r\nsites (P<0.05). Also a significant bone resorption in control site and successful socket preservation\r\nin experimental site were observed. Reduction of root resorption at the augmented site was\r\nsignificant compared to the normal healing site (P<0.05).\r\nConclusion: Using socket preservation, tooth movement can be immediately started without\r\nwaiting for the healing of the recipient site. This can provide some advantages like enhanced rate\r\nof OTM, its approved effects on ridge preservation that reduces the chance of dehiscence and the\r\nreduction of root resorption....
Background: Tissue engineering principles can be exploited to enhance alveolar and peri-implant\r\nbone reconstruction by applying such biological factors as platelet-derived growth factors. The\r\nobjective of the present study is to investigate the effect of autologous plasma-rich in growth\r\nfactors (on the healing of peri-implant bone in canine mandible).\r\nMaterials and Methods: In this prospective experimental animal study, two healthy canines of\r\nthe Iranian mix breed were selected. Three months after removing their premolar teeth on both\r\nsides of the mandible, 12 implants of the Osteo Implant Corporationsystem, 5 mm in diameter\r\nand 10 mm in length, were selected to be implanted. Plasma rich in growth factors (PRGF) were\r\napplied on six implants while the other six were used as plain implants without the plasma. The\r\nimplants were installed in osteotomy sites on both sides of the mandible to be removed after 4\r\nweeks with the surrounding bones using a trephine bur. Mesio-distal sections and implant blocks,\r\n50 �µ in diameter containing the peri-implant bone, were prepared By basic fuchin toluidine-bluefor\r\nhistological and histomorphometric evaluation by optical microscope. The data were analyzed using\r\nMann-Whitney Test (P<0.05).\r\nResults: The bone trabeculae and the type of bone generation in PRGF and control groups had\r\nno statistically significant differences (P=0.261, P=0.2) although the parameters showed higher\r\nmeasured values in the PRGF group. However, compared to the control, application of PRGF had\r\nsignificantly increased bone-to-implant contact (P=0.028)\r\nConclusion: Based on the results, it may be concluded that application of PRGF on the surface\r\nof implant may enhance bone-to-implant contact....
Background: Dental cobalt base alloys are biocompatible dental materials and have been widely\r\nused in dentistry. However, metals are bioinert and may not present bioactivity in human body.\r\nBioactivity is the especial ability to interact with human body and make a bonding to soft and hard\r\ntissues. The aim of the present research was fabrication and bioactivity evaluation of novel cobalt alloy/\r\nFluorapatite nanocomposite (CoA/FaNC) with different amounts of Fluorapatite (FA) nanopowder.\r\nMaterials and Methods: Co-Cr-Mo alloy (ASTM F75) powder was prepared and mixed in a\r\nplanetary ball mill with different amounts of FA nanopowders (10, 15, 20% wt). Prepared composite\r\npowders were cold pressed and sintered at 1100�°C for 4 h. X-ray diffraction (XRD), scanning\r\nelectron microscopy and transition electron microscopy techniques were used for phase analysis,\r\ncrystallite size determination of FA and also for phase analysis and evaluation of particle distribution\r\nof composites. Bioactivity behavior of prepared nanocomposites was evaluated in simulated body\r\nfluid (SBF) for 1 up to 28 days.\r\nResults: Results showed that nucleus of apatite were formed on the surface of the prepared CoA/\r\nFaNC during 1 up to 28 days immersion in the SBF solution. On the other hand, CoA/FaNC unlike\r\nCo-base alloy possessed bone-like apatite-formation ability.\r\nConclusion: It was concluded that bioinert Co-Cr-Mo alloy could be successfully converted into\r\nbioactive nanocomposite by adding 10, 15, 20 wt% of FA nano particles....
Dental professionals are predisposed to a number of occupational hazards. These include exposure\r\nto infections (including Human Immunodeficiency Virus and viral hepatitis); percutaneous exposure\r\nincidents, dental materials, radiation, and noise; musculoskeletal disorders; psychological problems\r\nand dermatitis; respiratory disorders; and eye insults. Percutaneous exposure incidents remain a\r\nmain concern, as exposure to serious infectious agents is a virtual risk. Minimizing percutaneous\r\nexposure incidents and their consequences should continue to be considered, including sound\r\ninfection control practices, continuing education, and hepatitis B vaccination. Basically, for any\r\ninfection control strategies, dentists should be aware of individual protective measures and\r\nappropriate sterilization or other high-level disinfection utilities. Strained posture at work disturbs\r\nthe musculoskeletal alignment and leads to stooped spine. The stooped posture also involved\r\ncertain groups of muscles and joints. This may lead to diseases of the musculoskeletal system.\r\nContinuous educating and appropriate intervention studies are needed to reduce the complication\r\nof these hazards. So, it is important for dentists to remain constantly up-to-date about measures\r\non how to deal with newer strategies and dental materials, and implicates the need for special\r\nmedical care for this professional group....
Background: Antioxidizing agents have recently been suggested to compensate decreased bond\r\nstrength of resin materials to bleached tooth tissues. This study compared the shear bond strength\r\n(SBS) of three different adhesives on bleached dentin immediately after bleaching, bleached/delayed\r\nfor 1 week, and bleached/applied antioxidizing agent.\r\nMaterials and Methods: The dentinal surfaces of 132 intact extracted molars were prepared and\r\ndivided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step\r\netch-and-rinse), Optibond Solo Plus (two-step etch-and-rinse), and Optibond all-in-one (OA) (onestep\r\nself-etch) (Kerr, Orange, USA). Unbleached dentin groups (groups 1-3) were prepared as negative\r\ncontrols (NC). The remainder surfaces (groups 4-12) were bleached with 20% Opalescent PF (Ultradent,\r\nUSA). Specimens were bonded immediately after bleaching (groups 4-6), after 1 week (groups 7-9), or\r\nafter using 10% sodium ascorbate (SA) gel (groups 10-12). Subsequent to bonding of composite resin,\r\nthe samples were tested for SBS and analyzed using Kruskal-Wallis and Mann-Whitney tests (a=0.05).\r\nResults: Regarding control groups, OA showed the highest SBS among the studied adhesives\r\n(P<0.05). The SBS decreased for the adhesives after bleaching except for OFL. No statistically\r\nsignificant difference in SBS were noted when the SA and delayed bonding groups were compared\r\nwith their similar NC groups (P>0.05) except the of delay bonding with OA.\r\nConclusions: The findings suggest that bond strength of resin to bleached dentin may be affected\r\nwith the adhesive system. Reduced SBS to bleached dentin can be amended by the use of SA as\r\nan antioxidizing agent. However, the amount of reversed bond strength subsequent to applying\r\nantioxidant might be related to the kind of dental adhesive....
angulation, level, amount of space for eruption of third molar between ramus of mandible and\r\nsecond molar and the eruption status of third molar in a group of Libyan students, with different\r\nimpaction patterns and agenesis of third molars.\r\nMaterials and Methods: In this descriptive retrospective study, a total of 200 students (100 male and\r\n100 female students of bachelor of dental surgery, Faculty of Dentistry, Garyounis University, Benghazi,\r\nLibya) were enrolled. Students who had complete complement of teeth within the age group 17ââ?¬â??26 years\r\nwere selected for this study, while those cases who had history of extraction of any of the teeth or\r\nwho refused to give consent were excluded. Before starting the study, ethical concern from the ethical\r\ncommittee, IRB and informed consent from each student who underwent radiography were obtained.\r\nResults: The results showed that 5% of third molars were congenitally missing. Approximately\r\n93.5% of the subjects had all four third molars, 1% had two third molars and 0.5% had one third\r\nmolars with 2.5% having agenesis of all third molars. Third molar agenesis showed predilection for\r\nmaxilla with higher proportion in females (3%) than males (2.1%). Angular position was maximum\r\nwith vertical position (5.83%), with least being horizontal impactions. Level of occlusal plane of third\r\nmolar similar to that of adjacent tooth was seen in 44.74%, below the occlusal plane in 24.76%,\r\ntotally impacted noted in 30%.\r\nConclusion: The present study showed that 33% of the teeth were fully erupted and 66% were\r\nin various stages of eruption and 5% were congenitally missing in these students....
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