Journal of Dental Medicine

The present clinical trial was designed to evaluate the regenerative potential of periodontal tissues in degree II furcation defects at mandibular molars of human using a slow-resorbing collagen membrane and a surgical treatment technique based on the principles of guided tissue regeneration.The patient sampleinclude 8 subjects who had periodontal lessions in right and left mandibular molars regions, including moderate to advance periodonal destruction within the radicular area. Following a baseline examination including recording the clinical measurements (PD, Al, HC, F.G.M) , the furcation- involved molars were randomly assigned in each patient to either a test or a control treatment procedure. Included the evevation of mucoperiosteal flaps, recording measurement from the cemento enamel junction (C.E.J) directly coronal to the furcation area to the alveolar crest and to the base of the defect-Horizontal furcation measurements were also made using a William's probe, finally a collagen membrrane placed on the involved area to cover the entrance of the furcation and adjucent root surfaces as well as a portion of the alveolar bone apical to the crest. The flaps were repositioned and secured with interdental sutures. A procedure identical to the one used at the test teeth was Performed at the control teeth region with the exception of the placement of the collagen membrance. Following surgery all patients were placed on a plaque control regimen. All Patients received normal postsurgical care and at 6 month post-surgery were scheduled for re-entry surgery. Before re-entry surgery all clinical parameters recorded again. The re-entry mucoperiosteal flaps were designed to expose the furcation area for measurements, as describedabove. There was clinical improvement in all measurements made in both the test and control patients (especially in test group) over the 6 month period. The horizontal and vertical furcation measurements did yield a statistically significant imporvement when companing the test patients to the control.

Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and differentiation by acting on specific receptors on the surface of cells and regulating events in wound healing.They can be considered hormones that are not released in to the blood stream but have one a local action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion cycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted by fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor (PDGF), insulin like growth factor (IGF) transforming growth factor (TGF)a and (3 and bone morphogenetic proteins BMPs that approximately are the most important of them. (BMP)s could be used to control events during periodontal, craniofacial and implant wound healing through favoring bone formation According toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the components of the periodontium.The aim of this study was to characterize growth factor and review the literature to determine the mechanism of their function, classification and application in implant and periodontal treatment.

Guided Tissue Regeneration (GTR) is the most recent and common method for regeneration of class II forcation molars. However, it requires membrane, which seems expensive for most of the patients. In order to overcome this problem, Coronally Position Flap (CPF) procedure may be applied which arresting the epithelial cell down growth, follow the same aim. This study is aimed to compare GTR technique utilizing bioresorable collagen membrane and CPF utilizing citric acid. Nine patients with grade II forcation defects were selected. Defects were bilateral that randomly assigned into two groups: GTR and CPF groups. Measurements recorded at baseline and after surgery (6 months). Paired-T test was performed on these data. The following results were obtained after 6 months: In both groups significant reduction in probing pocket depth were measured in GTR and CPF groups, 1.55 Ind 1.88 mm, respectively. Also, open vertical probing depth: 0.33, 1.11 mm. Reduction in forcation weight in both groups was 0.22 mm. Bone fill was observed in 0.33% and 51% of defects. No recession was observed in GTR group, in CPF was 0.11 mm. Loss of attached gingiva was 0.34 and 0.78 mm, respectively. No significant difference was found between clinical parameters except OHPD. Comparison of means at the day (0 and 180) in each group showed the success for regeneration of forca. Considering the results, it can be concluded that CPF may substitute for GTR technique.

The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

Statement of Problem: One of the problems associated with the treatment of periodontal diseases is caused through the extension of disease toward furcation area. Several techniques in Conservative, Resective and Regenerative categories have been suggested for the treatment of furcation involvement.
Purpose: The aim of this study was to compare the results of the treatment of grade II furcation involvement in mandibular molars using an allograft material named 'Dynagraft' (a type of demineralized bone matrix) and the coronally positioned flap.

Materials and Methods: In this randomized controlled clinical trial study, twelve patients (9 females and 3 males), aged 25 to 40, suffering from bilaterally grade II furcation involvement of mandibular molars who referred to dental faculty Tehran University of medical Sciences, were investigated. The molars of one side were treated by Dynagraft whereas those of the opposite side underwent the CPF method. Measurements of the probing pocket depth (PPD), clinical attachment level (CAL), keratinized gingiva (KG) and horizontal probing depth (HPD) were recorded at baseline, 3 and 6 months after surgery. In order to investigate the bone radiographic changes, radiovisiography at the mentioned periods in addition to clinical investigation, were performed. For statistical analysis, Paired West was used.
Results: The mean PPD reduction three months and six months after the operation were 1.75 mm and 2.25mm, respectively in the Dynagraft (test) group whereas 1.26mm and 1.27mm in the CPF (control) group (P<0.005). The mean attachment gain three months and six months after the operation were 1.1 mm and 1.5mm respectively in the test group, and 0.2mm and 0.3mm in the control group (P<0.005). The mean KG reduction three months and six months after the operation were 0.5mm and 0.6mm respectively in the test group and those of the control group were 1.1mm and 1.1mm. The mean HPD reduction three months and six months after the operation were 1.55mm and 2mm respectively in the test group (P<0.005) and 0.55mm and 0.55mm in the control group (PO.01). Radiovisiography of the mentioned areas three months and six months after the operation confirmed the changes obtained from clinical measurements, showing appreciable reconstructive results (Bone filling) in the test group as compared with the control group. Moreover, root resorption was not observed.
Conclusion: Based on the results of this study, Dynagraft can be used as an appropriate material in the treatment of grade II furcation involvement in mandibular molars. However, for a through evaluation of such regenerative techniques in furcation involvement, further studies with larger population and long term follow up in addition to histologic studies are suggested.

Background and Aim: Increasing patient demands for esthetic, put the root coverage procedures in particular attention. Periodontal regeneration with GTR based root coverage methods is the most common treatment used. The purpose of this study was to compare guided tissue regeneration (GTR) with collagen membrane and a bone graft, with sub-epithelial connective tissue graft (SCTG), in treatment of gingival recession.

Materials and Methods: In this randomized clinical trial study, eleven healthy patients with no systemic diseases who had miller’s class I or II recession defects (gingival recession  2mm) were treated with SCTG or GTR using a collagen membrane and a bone graft. Clinical measurements were obtained at baseline and 6 months after surgery. These clinical measurements included recession depth (RD), recession width (RW), probing depth (PD), and clinical attachment level (CAL). Data were analyzed using independent t test with p<0.05 as the limit of significance.

Results: Both treatment methods resulted in a statistically significant reduction of recession depth (SCTG=2.3mm, GTR=2.1mm P<0.0001). CAL gain after 6 months was also improved in both groups (SCG= 2.5mm, GTR=2.1mm), compared to baseline (P<0.0001). No statistical differences were observed in RD, RW, CAL between test and control groups. Root coverage was similar in both methods (SCTG= 74.2%, GTR= 62.6%, P=0.87).

Conclusion: Based on the results of this study, the two techniques are clinically comparable. Therefore the use of collagen membrane and a bovine derived xenograft may alleviate the need for connective tissue graft.

Background and Aim: Furcation defects are one of the most challenging problems in periodontal therapy. Regenerative treatment significantly improves the prognosis of the involved teeth. The aim of this study was to compare Bio-Oss plus 10% collagen in combination with either a bioabsorbable collagen barrier (BO/GTR), or coronally advanced flap (BO/CF), in treating human mandibular class II furcation defects.

Materials and Methods: This clinical trial included 10 patients with 10 pairs of similar periodontal defects. Each defect was randomly assigned to treatment with BO/CF or BO/GTR. Following basic therapy, baseline measurements were recorded including probing pocket depth (PPD),closed horizontal probing depth (CHPD), clinical attachment level (CAL), and gingival margin position (CEJ-GM), together with plaque and gingival indices. Hard tissue measurements were performed during surgery to determine alveolar crestal height (CEJ-AC), and vertical and horizontal open probing depth (OVPD, OHPD).After 6 months, all sites were re-entered and soft and hard tissue measurements were recorded.

Results: Both surgical procedures significantly reduced probing depth and improved clinical attachment levels, with no significant difference between groups. Gingival margin position (CEJ-GM), was improved in the BO/CF group (0.66±0.51 mm, p<0.05), but not statistically different from BO/GTR group in which remained relatively constant (0.00±0.81 mm). Vertical defect resolution was significant in each groups (BO/CF:3.17±1.47 mm, BO/GTR:3.33±0.51mm). Horizontal defect resolution was also significant with either procedure (BO/CF:3.67±1.31 mm, BO/GTR:3.80±1.83 mm), with no statistically significant difference between groups. Data were analyzed with wilcoxon and Mann-Whitney tests with p<0.05 as the level of significance.

Conclusion: Based on the results of this study, treatment of mandibular class II furcation defects with both procedures resulted in statistically significant improvement in open and closed probing measurements, with no significant difference between treatment groups. In BO/CF group there was an additional improvement in gingival recession (CEJ-GM) measurement, which could be attributed to applying crown-attached sutures by the use of orthodontic brackets.

Background and Aim: The aim of this investigation was to evaluate the osteopromotion property of homogenous demineralized dentin matrix (HDDM) on experimental surgical bone defects in parietal bone of rabbits using the guided bone regeneration (G.B.R.) technique incorporating Paroguide collagen membrane.

Materials and Methods: Surgical bone defects were created in 6 Newzland white rabbits (2 defects in each rabbit). The defects were protected by Paroguide membrane alone (control group) or filled with HDDM and protected by Paroguide membrane (experimental group). The HDDM had been obtained from the central incisors of rabbits. The rabbits were sacrificed after 15, 30, 45, 60, 75 and 90 days and the defects examined histologically. Data were analyzed using pair-t test. The level of significance was set at p=0.03.

Results: Histologically, the volume of newly formed bone matrix was significantly greater in the experimental group. No inflammatory reaction was seen in either experimental or control groups.

Conclusion: Bone regeneration was accelerated in the bone defects filled with HDDM in comparison to the control group.

Background and Aims: Nowadays reconstruction of alveolar defects has become one of dentists' problems especially in areas which are going to get dental implants. Inorganic bovine bone mineral (Bio-Oss) is one of the most popular graft materials that acts as a structure for migration of osteoblasts. If migration, proliferation, and differentiation of osteoblasts can be promoted by a material, it would be possible to reconstruct more amount of bone in a shorter period of time. Milk contains vital proteins that regulate bone growth. One of these important proteins is lactoferrin. The aim of this study was to examine the effect of added bovine lactoferrin to Bio-Oss on osteogenesis.
Materials and Methods: Two doses of 50 and 500 µg/ml of lactoferrin were prepared. Ten New Zealand white rabbits were selected for this study. Four 6-mm symmetrical detects were created in each rabbit's calvarium. Two of these sites were filled with Bio-Oss that was wetted with two doses of lactoferrin. Third detect was filled with Bio-Oss alone and the forth one was left empty as control group. After 4 weeks histologic and histomorphometric analysis was performed.
Result: There was no sign of obvious inflammation in any of four groups. Also there was no difference among four groups in terms of vitality, type of new bone, and foreign body reaction. However, amount of bone formation in control group was significantly lower compared with the other 3 groups. Although lactoferrin containing groups showed little increase in bone formation especially in higher concentration, there was not statistically significant difference among the three test groups. Amount of remaining biomaterial also was lower in lactoferrin containing groups compared with the Bio-Oss group but the differences were not significant.
Conclusion: Although there was no significant difference among the test groups, it seems that the added lactoferrin increases bone formation. Considering the limitations of this study, more studies are needed in different concentrations of lactoferrin and different healing periods. Furthermore, because of possible washout of the lactoferrin from the defects, it would be helpful to find and evaluate a proper carrier agent for lactoferrin to see its real effects.

Dentistry has been a field dominated by a constant improvement of synthetic biomaterials. Tissue engineering of tooth is coming to change the panel of the dental materials such as restorative materials and implants. Certainly, it is the largest transition in history of dental materials science in terms of accepting this new and exciting technology. The objective of this article is to present various implications of tissue engineering in different fields of dentistry. To achieve this goal, a review of the literature was carried out by using Medline database to search topics including "dental stem cells", "teeth tissue engineering", "regenerative dentistry", "oral surgery", "periodontal regeneration" and "regenerative endodontics". These searches were limited to articles published after the year 2000. On the basis of our literature review, we have found that although there are significant challenges in oral tissues engineering, engineered tissues will find many applications in dentistry within the next few years.

  Background and Aims: In the last decade, several studies have reported the isolation of stem cell population from different dental sources, while their mesenchymal nature is still controversial. The aim of this study was to introduce the isolating methods for stem cells from human dental pulp and to determine their mesenchymal nature before differentiation.

  Material and methods: One of the best sources for stem cell is dental pulp tissue. Dental Pulp Stem Cells (DPSCs) would be the most convenient source of stem cells because teeth were easy to retrieve and removed throughout life. Pulp is a specialized connective tissue including blood and lymph vessels, nerves, and the interstitial fluid. DPSCs can be found within the ‘‘cell rich zone’’ of pulp. DPSCs have been isolated for the first time in 2000 by Gronthos these cells exhibited a differentiation potential for odontoblastic, adipogenic and neural cytotypes. Gronthos isolated stem cells in 2 different methods: The enzymatic digestion method and the second was out growth, these cells could be cryopreserved in liquid nitrogen. It has also been shown that human DPSCs can be used for complex structures such as pulp or woven bone formation in vivo.

  Conclusion: DPSCs originate from the cranial neural crest and have neural characteristics such as the expression of neurotrophins. Therefore, DPSCs may represent a promising source in cell therapy for neurological disorders. Characterization of these cells and determination of their potentialities in terms of specificity of regenerative response will form the foundation for development of new clinical treatment modalities, whether involving directed recruitment of the cells and seeding of stem cells at sites of injury for regeneration or use of the stem cells with appropriate scaffolds for tissue engineering solutions. Such approaches will provide an innovative and novel biologically based on new generation of clinical treatments for dental disease.