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Dental Research, Dental Clinics, Dental Prospects - Volume:11 Issue: 2, Spring 2017

Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:11 Issue: 2, Spring 2017

  • تاریخ انتشار: 1396/04/18
  • تعداد عناوین: 11
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  • Janet Moradi Haghgoo, Seyed Reza Arabi, Seyyed Mohammad Hosseinipanah, Ghasem Solgi, Neda Rastegarfard*, Maryam Farhadian Pages 73-77
    Background. This study was designed to compare the viability of autogenous bone grafts, harvested using different methods, in order to determine the best harvesting technique with respect to more viable cells.
    Methods. In this animal experimental study, three harvesting methods, including manual instrument (chisel), rotary device and piezosurgery, were used for harvesting bone grafts from the lateral body of the mandible on the left and right sides of 10 rabbits. In each group, 20 bone samples were collected and their viability was assessed using MTS kit. Statistical analyses, including ANOVA and post hoc Tukey tests, were used for evaluating significant differences between the groups.
    Results. One-way ANOVA showed significant differences between all the groups (P=0.000). Data analysis using post hoc Tukey tests indicated that manual instrument and piezosurgery had no significant differences with regard to cell viability (P=0.749) and the cell viability in both groups was higher than that with the use of a rotary instrument (P=0.000).
    Conclusion. Autogenous bone grafts harvested with a manual instrument and piezosurgery had more viable cells in comparison to the bone chips harvested with a rotary device.
    Keywords: Autograft, autologous transplants, dental Instruments, piezosurgery, tissue harvesting
  • Hanif Allahbakhshi*, Fariborz Vafaee, Mehrdad Lotfazar, Ahmad Hasan Ahangary, Masoumeh Khoshhal, Farnoush Fotovat Pages 78-83
    Background. Delayed loading is one of the concerns in implant patients. Immediate loading can solve the problem and make patients more satisfied. The present study aimed to compare the removal torque of maxi implants under different loading (immediate and delayed) patterns.
    Methods. This split-mouth experimental study included 2 dogs. Impressions were made and then all the premolars were extracted under general anesthesia. After a three-month healing period, 3 implants were inserted in each quadrant (a total of 12 implants). Anterior and posterior implants (the case group) were splinted by an acrylic temporary bridge in order to make the middle implants (the control group) off the occlusion. The dogs were sacrificed after 6 weeks and bone blocks were submitted for removal torque test. Data were analyzed with ANOVA (PResults. Mean torque values for the cases and control groups were 46.82±25.58 and 59.88±15.19, respectively (P=0.582; not significant).
    Conclusion. It may be concluded that immediate loading does not reduce the reverse torque values of maxi implants. This supports the advantages of immediate loading for maxi implants.
    Keywords: Denture, dental implant, dog, fixed, osseointegration, partial
  • Shahriar Shahi, Asmar Bashirzadeh, Hamid Reza Yavari Yavari, Farnaz Jafari*, Amin Salem Milani, Negin Ghasemi, Mohammad Samiei Pages 84-89
    Background. The aim of this study was to investigate the effect of different mixing methods (ultrasonic, amalgamator, and conventional) on the bacterial microleakage of white Portland cement (WPC) and white MTA (Tooth-colored Formula, Dentsply, Tulsa Dental, Tulsa, OK).
    Methods. A hundred human single-rooted permanent teeth were decoronated to obtain 14 mm of root length in all the samples. The root canals were cleaned, shaped and obturated. Three millimeters of each root apex were cut off and randomly divided into 6 groups of 15 each (3 groups for WMTA and 3 groups for WPC, each with 3 different mixing methods) and 2 positive and negative control groups (each containing 5 samples). Brain-heart infusion agar (BHI) suspension containing the bacterial species Enterococcus faecalis (ATCC 29212) was used for leakage assessment. Statistical analysis was carried out using descriptive statistics and Kaplan Mayer survival analysis with censored data and log rank test using SPSS 18. Statistical significance was set at PResults. The survival means in PC for conventional method, amalgamator, and ultrasonic were 80.2±13.64, 78.5±13.46 and 84.667±11.42 days, with 49.13±12.96, 66±13.32 and 69.07±11.5 days for MTA, respectively. The log rank test showed no significant differences between the three methods in each material (P>0.05).
    Conclusion. Bacterial microleakage in the studied samples was not significantly different in terms of the type of the mixing method.
    Keywords: Dental cement, dental leakage, Enterococcus faecalis, MTA, mixing method
  • Mehmet, Ccedil, Itak, Taha, Ouml, ZyÜrek* Pages 90-95
    Background. The aim of this study was to compare the dentinal defects caused by Reciproc, TF Adaptive and ProTaper Next NiTi rotary file systems during the retreatment procedure.
    Methods. A total of 150 mandibular incisors with straight and single root canals were included in the present study. All the root canals were prepared up to an apical diameter 0.40 mm using stainless steel files. Thirty teeth were randomly stored as the negative control group. A total of 120 specimens were obturated with gutta-percha and AH Plus sealer using vertical compaction technique. Thirty specimens with root canal filling were randomly separated for the only-filled group. Then the teeth were randomly divided into 3 groups; Reciproc, TF Adaptive and ProTaper Next. The retreatment procedure was performed with these NiTi files. Then 150 specimens were cut perpendicular to tooth axis at 3-, 6-, and 9-mm distances from the apex, and examined to determine the presence of any cracks at ×25 under a stereomicroscope. Chi-squared test was used at 5% significance level.
    Results. All the tested NiTi file systems were found to cause significantly more dentinal defects compared to unprepared and only-filled groups (P0.05). No correlation was found between the slice levels and the dentinal defect distribution (P>0.05).
    Conclusion. Within the limitations of present study, all the tested NiTi file systems were found to cause significantly more dentinal defects compared to unprepared and only-filled groups.
    Keywords: Dentinal crack, ProTaper Next, Retreatment, Reciproc, TF Adaptive
  • Manisha Chandwani*, Rakesh Mittal, Shweta Chandak, Ashish Bhondey, Anand Rathi Pages 96-100
    Background. The current research aimed to assess the prevalence of facultative anaerobes isolated from the root canals of deciduous molars.
    Methods. The present research enrolled 60 children in the 6‒9-year age group based on clinical and radiographic findings. Under aseptic conditions, access cavities were prepared followed by collection of samples from infected root canals with the help of sterile paper points. The samples thus obtained were subjected for microbial assay.
    Results. It was found that Enterococcus faecalis was isolated in 30% of cases, Escherichia coli in 28.4%, Staphylococcus aureus in 25%, α-hemolytic Streptococci in 15% and Proteus mirabilis in 1.6% of cases.
    Conclusion. It was concluded from the results of the present study that the root canals of deciduous molars had predominance of facultative anaerobes, confirming its polymicrobial nature. This identification of microbes is crucial as it aids in understanding the pathogenesis of pulpal and periradicular diseases to provide effective antimicrobial irrigation and medicament for endodontic treatment.
    Keywords: Deciduous tooth, microorganisms, root canal
  • Siavash Savadi Oskoee, Mahmoud Bahari*, Elmira Jafari Navimipour, Amir Ahmad Ajami, Negar Ghiasvand, Ayda Savadi Oskoee Pages 101-109
    Background. Bulk-fill composite resins are a new type of resin-based composite resins, claimed to have the capacity to be placed in thick layers, up to 4 mm. This study was carried out to evaluate factors affecting gap formation in Cl II cavities restored using the bulk-fill technique.
    Methods. A total of 60 third molars were used in this study. Two Cl II cavities were prepared in each tooth, one on the mesial aspect 1 mm coronal to the CEJ and one on the distal aspect 1 mm apical to the CEJ. The teeth were divided into 4 groups: A: The cavities were restored using the bulk-fill technique with Filtek P90 composite resin and its adhesive system and light-cured with quartz tungsten halogen (QTH) light-curing unit. B: The cavities were restored similar to that in group A but light-cured with an LED light-curing unit. C: The cavities were restored using the bulk-fill technique with X-tra Fil composite resin and Clearfil SE Bond adhesive system and light-cured with a QTH curing unit. D: The cavities were restored similar to that in group C but light-cured with an LED light-curing unit. The gaps were examined under a stereomicroscope at ×60. Data were analyzed with General Linear Model test. In cases of statistical significance (PResults. The light-curing unit type had no effect on gap formation. However, the results were significant in relation to the composite resin type and margin location (PConclusion. X-tra Fil composite exhibited smaller gaps compared with Filtek P90 composite with both light-curing units. Both composite resins exhibited smaller gaps at enamel margins.
    Keywords: Composite resin, bulk fill, curing light, marginal gap, silorane, methacrylate
  • Fariba Saleh Saber, Nader Abolfazli, Soheil Jannatii Ataei, Mahsa Taghizade Motlagh, Vahede Gharekhani* Pages 110-116
    Background. Since the misfit of crown has an important role in clinical performance of implant-supported prostheses, and due to the impact of the settling effect on misfit, the aim of this study was to investigate the impact of torque forces on the total lengths of narrow and short implant abutments in different internal implant‒abutment connections.
    Methods. In four different implant‒abutment connections, 8 analog implants with a normal diameter (4 mm) and narrow abutment (4.5 mm) were selected from groups of internal hex, internal octagon, morse hex 6° and morse hex 11°. Each of them was mounted within plaster type IV, and 32 samples were obtained. Then, the amount of vertical displacement was measured by closing the impression copings and applying torques of 20 25 and 30 Ncm. This stage was repeated for the abutment. In the next stage, the resin pattern was built and measurements were performed after applying the torques mentioned. Finally, after making the frame, this stage was repeated, and the settling effect was statistically analyzed with ANOVA.
    Results. In the stages of impression coping, resin pattern and final prosthesis, HEXAGONE had significantly the highest and OCTAGONE had the lowest rates of settling, and the settling of morse hex 11° and 6° was between them.
    Conclusion. Octagon implant had significantly the lowest settling in various clinical and laboratory stages by applying different torques.
    Keywords: Axial displacement, morse hex taper, settling effect, tightening torque
  • Madu Ghana Shyam Prasad*, Juvva Ramakrishna, Duvvi Naveen Babu Pages 117-122
    Stem cells are the pluripotent cells that have the capacity to differentiate into other specialized cells. Recently, many experiments have been conducted to study the potentiality of stem cells in the tissue regeneration. We report two cases treated utilizing stem cells from human exfoliated deciduous teeth (SHED) in the management of periapical lesions in permanent teeth. Two normal human deciduous teeth from children, 7‒8 years of age, were collected to isolate stem cells. Two patients, one with periapical pathology alone and the other with periapical lesion along with an open apex in young permanent teeth, were selected for the study. After initial debridement of the root canals, homing of SHED was carried out and the access cavity was sealed using glass-ionomer cement. Clinical examination after 7 days, 30 days, 90 days, 180 days and 365 days revealed no symptoms. Closure of open apex and periapical tissue healing were observed radiographically at one-month review and maintained until 365-day review. Positive response to electric pulp testing was recorded for the treated teeth from the 3- to 12-month follow-ups. The treated cases demonstrated complete resolution of periapical radiolucency in a span of 30 days, which was faster than the conventional methods. SHED could be considred effective in treating the periapical lesions and open apex in permanent teeth.
    Keywords: Periapical lesions, permanent teeth, pulp necrosis, bioglass, stem cells, tissue scaffolds
  • Vandana Kl*, Haneet Ryana, Priyanka Jairaj Dalvi Pages 123-126
    Numerous animal and human studies have provided evidence supporting the belief that periodontal ligament stem cells (PDLSCs) can be harnessed for regeneration of periodontal tissues. Based on current literature on the use of ex vivo stem culture and associated problems, this case report describes a novel approach of direct application PDLSCs using stem cell assistance in periodontal regeneration technique (SAI-PRT) for the regeneration of intrabony periodontal defects bypassing ex vivo cultures. SAI-PRT has emerged as a constructive avenue in the treatment of periodontal osseous defects. Moreover, the current technique is less technique-sensitive, cost-effective and yields promising results.
    Keywords: Osseous defects, periodontal regeneration, periodontitis, stem cells
  • Suresh Kv*_Pramod R. C_Seema Roodmal Yadav_Nilesh Kumar_Mounesh Kumar C. D C. D_Sreeja P. Kumar Pages 127-130
    Dental anomalies affecting the teeth are relatively common. Simultaneous occurrence of multiple dental abnormalities in a single tooth is uncommon and relatively rare. One such abnormality routinely encountered in dental clinics is the talon cusp. It is also referred to as dens evaginatus, characterized by the presence of an accessory cusp-like structure projecting from the cingulum of anterior teeth. It has an increased predilection for maxillary teeth and permanent dentition. Although numerous cases of talon cusp have been reported in the literature, occurrence of multiple talon cusps in maxillary central incisors has not been found in the literature. This case report highlights the presence of talon cusps in maxillary anterior teeth with multiple impacted supernumerary teeth.
    Keywords: Dens evaginatus, maxilla, multiple, supernumerary tooth, talon cusp
  • Somayeh Hekmatfar, Karim Jafari*, Firoz Zadfatah, Sahar Mousavi Pages 131-134
    Tooth transposition, which is a rare condition, is ascribed to the disturbance of tooth eruption and the subsequent abnormal occlusal relationships. Transpositions mostly involve the upper jaw and more frequently occur between the maxillary canine and first premolar. Herein, we present a case of a maxillary canine‒second molar transposition in a thalassemic patient.
    Keywords: Maxillary canine, transposition, thalassemia