Development of antibacterial collagen membranes with optimal silver nanoparticle content for periodontal regeneration.

The effective control of pathogenic bacteria is crucial in the restoration of periodontal tissue affected by periodontitis. Guided tissue regeneration (GTR) membranes are commonly used to aid in the repair of periodontal defects. Therefore, there is a clear advantage in developing antibacterial periodontal membranes that can effectively eliminate infections and promote tissue regeneration. This study aimed to create a collagen membrane with optimal content of silver nanoparticles (AgNPs) for effective antibacterial properties and minimal toxicity to mammalian cells. Ascorbic acid-reduced AgNPs were incorporated into collagen at the ratio of 0.5%, 1%, 2%, and 3% (based on total dry weight). Collagen/AgNPs hydrogels were compressed and freeze-dried to form membranes and then were characterized. Antibacterial activity was tested against Fusobacterium nucleatum and Enterococcus faecalis, and membrane cytocompatibility was accomplished on human gingival fibroblasts. Membranes with 2% and 3% AgNPs exhibited significant antibacterial activity, while 1% showed minimal activity and 0.5% and 0% showed none. HGF cells on the 3% AgNPs membrane had poor viability, proliferation, and adhesion, but 0%, 0.5%, 1%, and 2% AgNPs membranes showed desirable cellular behavior. In conclusion, the collagen membrane with 2% AgNPs demonstrated both antibacterial capacity and excellent cytocompatibility, making it a promising choice for periodontal treatments, especially in GTR approaches.

Addressing Antimicrobial Properties in Guided Tissue/Bone Regeneration Membrane: Enhancing Effectiveness in Periodontitis Treatment.

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) are the two surgical techniques generally used for periodontitis disease treatment. These techniques are based on a barrier membrane to direct the growth of new bone and gingival tissue at sites with insufficient volumes or dimensions of bone or gingiva for proper function, esthetics, or prosthetic restoration. Numerous studies have highlighted biocompatibility, space-creation, cell-blocking, bioactivity, and proper handling as essential characteristics of a membrane's performance. Given that bacterial infection is the primary cause of periodontitis, we strongly believe that addressing the antimicrobial properties of these membranes is of utmost importance. Indeed, the absence of effective inhibition of periodontal pathogens has been recognized as a primary factor contributing to the failure of GTR/GBR membranes. Therefore, we suggest considering antimicrobial properties as one of the key factors in the design of GTR/GBR membranes. Antibiotics are potent medications frequently administered systemically to combat microbes and mitigate bacterial infections. Nevertheless, the excessive use of antibiotics has resulted in a surge in bacterial resistance. To overcome this challenge, alternative antibacterial substances have been developed. In this review, we explore the utilization of alternative substances with antimicrobial properties for topical application in membranes. The use of antibacterial nanoparticles, phytochemical compounds, and antimicrobial peptides in this context was investigated. By carefully selecting and integrating antimicrobial agents into GTR/GBR membranes, we can significantly enhance their effectiveness in combating periodontitis. These antibacterial substances not only act as barriers against pathogenic bacteria but also promote the process of periodontal healing.

Evaluation of the Effect of Hyaluronic Acid Injection on the Reconstruction of Reduced Interdental Papillae in Patients Referred to Shiraz School of Dentistry.

Statement of the Problem: The occurrence of papillary defects adjacent to teeth or dental implants causes both the dental staff and the patients to be concerned about the esthetic issues. Interdental papilla reconstruction surgery is one of the most difficult and unpredictable mucogingival surgeries. Purpose: The present study aimed to investigate the efficacy of hyaluronic acid injection in the reconstruction of the interdental papilla. Materials and Method: This clinical trial study was conducted on four patients with 20 deficient interdental papillae who met the inclusion criteria. At first, local anesthesia was applied. Afterward, 0.2 mL of 1.6% hyaluronic acid (HA) gel was injected (at the tip of the papilla and 2-3 mm below the tip of the papilla) three times every two weeks. At baseline, three, and six months later, clinical photography was taken under standard conditions. The papilla height (the distance between the interdental papilla tip and the basis), black triangle area, and the distance between the interdental papilla tip and contact point of adjacent teeth were all measured using Image J software. Results: The effectiveness of using HA gel in reducing the black triangle area was 85.06%. Furthermore, the papilla length increased by 70.256% while contact to papilla distance decreased by 83.026%. At different times, the values of the studied variables in the three levels were significantly different (p< 0.05). Conclusion: Injection of HA with 1.6% concentration at two points of the interdental papilla was effective in interdental papilla reconstruction at the aesthetic zone, especially in long-term, follow-ups (especially 6 months).

Isolation and Identification of Non- Commensal Pathogenic Bacteria in the Saliva of Patients Candidate for Liver Transplant: A Cross Sectional Study in Shiraz, South of Iran.

STATEMENT OF THE PROBLEM: Liver cirrhosis is the end stage of liver failure. It is mentioned as one of the main etiologies of morbidity and mortality in the world. The human salivary bacteria may induce oral disorders and interact with other body microbiota. PURPOSE: The aim of the present study is to identify the pathogenic bacteria of non-oral origin from the saliva samples of patients with end stage liver failure. MATERIALS AND METHOD: In this cross-sectional study, the saliva samples of 88 end stage liver disease cases and 84 age- and sex-matched healthy subjects were collected. The samples were cultured using gram staining and API20E Kit. RESULTS: According to the statistical analysis, the total amount of the non-commensal bacteria was significantly higher in chronic liver failure (CLF) group than controls (p= 0.001). There was no significant difference between both groups for the presence of other bacteria (p= 0.001) except for Escherichia coli (E. coli). E. coli was isolated from the saliva of 15 cases and only 2 controls. CONCLUSION: Oral cavity may act as a reservoir for enteric bacteria such as E. coli in liver failure patients. Adequate oral and general hygiene might reduce the risk of systemic infection especially in immunocompromised cases.

Evaluation of Color and Width of Attached Gingiva Gain in Two Surgical Techniques: Free Gingival Graft and Connective Tissue Graft Covered By Thin Mucosal Flap, a Clinical Trial.

STATEMENT OF THE PROBLEM: The periodontal health and marginal stability of gingiva can be negatively affected by a number of dental conditions in association with deficiency of attached gingiva. PURPOSE: This study aimed to compare the color and width of tissue grafted by two surgical techniques of keratinized gingival augmentation, namely free gingival graft(FGG) and connective tissue graft (CTG) covered by thin mucosal flap . MATERIALS AND METHOD: This clinical trial was performed on 15 adult individuals. The patients showed less than 2mm keratinized gingiva on two different recipient sides. One side was to be treated with CTG as the test group and the other side to be treated with FGG as the control group. The amount of keratinized gingiva before the surgery, size of grafted tissue during the surgery and 6 month after the surgery was documented. Six months after healing, the test and control sides were compared in terms of the width of generated gingiva on both sides, and the color match of the grafted areas with the surrounding gingiva or mucosa. The color of the grafted areas was determined and compared by using both professional evaluation and digital evaluation. RESULTS: In digital evaluation, ∆E (which shows color mismatch) was higher in FGG. In professional evaluation, visual analogue scale (VAS) was used by two blinded periodontists. The mean VAS in FGG was less than CTG. The mean increase of gingival width was higher in CTG. The increased width in CTG technique was more than that in FGG technique. This difference was statistically, but not clinically, significant. CONCLUSION: Higher ∆E in control side and higher mean VAS CTG both showed better color adaptation of CTG side. FGG can be used in case of increasing keratinized gingiva, vestibular depth, and in patients with low smile line without esthetic concerns. However, using connective tissue in the underlying thin mucosal layer is preferred for gingival augmentation if there are adequate vestibule depth and esthetic concerns, like in maxillary canine.

Does Adding Silver Nanoparticles to Leukocyte- and Platelet-Rich Fibrin Improve Its Properties?

OBJECTIVES: Leucocyte- and platelet-rich fibrin (L-PRF) membrane can be used in various regenerative treatments. In the case of classical heterologous membrane exposure, microorganisms can be colonized on it and jeopardize the success of treatment. The aim of this study was to compare the antibacterial, mechanical, and histologic characteristics of the L-PRF membrane before and after the addition of silver nanoparticles (SNP). MATERIALS AND METHOD: This study was performed on 10 volunteer men aged 25-35 years. 20 ml whole bloods were collected from each person and L-PRFs were made by routine and SNP modified method. Mechanical, antibacterial, and histological properties were evaluated. RESULTS: The antibacterial efficacy of L-PRF and nanosilver-modified L-PRF was presented as Klebsiella pneumonia had growth on the L-PRF membrane after 12 hours. After 24 hours, Klebsiella pneumonia and Streptococcus viridans had growth on L-PRF and only Klebsiella pneumonia had growth on SNP-L-PRF. The tensile strength and stiffness were significantly higher in the SNP-L-PRF. Precipitation of the SNPs was patchy in the outer layers and quite homogeneous in the inner core. CONCLUSION: Modification of L-PRF with SNP improves the mechanical properties and antibacterial activity of the L-PRF. It can play an important role in regenerative procedures.

A Radiographic Evaluation of Missing of Permanent First Molars in a Group of Iranian Children and Adults: A Retrospective Study.

The missing of permanent first molars influences the occlusal status and dental health. The purpose of this study was to determine the prevalence of missing first molar teeth in a selected population of Shiraz, Iran. Methods. A total of 2206 panoramic views of patients aged from 7 to 75 years old were inspected for missing of permanent first molars. Patients were categorized into five age groups: from 7 to 15, 16 to 30, 31 to 45, 46 to 60, and more than 60 years old. Data were categorized according to sex, age, and number of lost teeth using SPSS software. Results. No first molar was missing in 59.9% of the cases, 17.05% had lost one, 10.4% had lost two, 7.2% had lost three, and 5% were missing all four of their permanent first molars. The mandibular first molar was the most commonly lost tooth, and the left side in both jaws was more affected than the right side. There was a positive relation between age and missing first molar. Conclusions. A missing first molar is a common finding in southern Iran population. Due to the important role of permanent first molars in occlusion, more education and dental care is recommended to preserve these teeth.

Effect of mouthrinses on color stability of monolithic zirconia and feldspathic ceramic: an in vitro study.

BACKGROUND: Patients susceptible to periodontal disease and dental caries, including those who undergo fixed prosthodontic treatments use chemical plaque control agents. However, these mouthrinses may result in adverse effects such as discoloration of the restorative materials. The aim of this study was to compare the color stability of monolithic zirconia and feldspathic porcelain after immersion in two different mouthrinses: 0.2% Chlorhexidine digluconate (CHX), or Listerine®. Color change was evaluated by color spectrophotometer and according to the Commission Internationale de l'Eclairage (CIELab) system. METHODS: We prepared 72 disc-shaped porcelains (n = 36) as follows: Group A consisted of dental direkt cube X2 discs (49% translucency) as the monolithic zirconia and group B consisted of VITA VMK 95 as a feldspathic porcelain. Groups A and B were divided into three subgroups (n = 12 per group). Each subgroup was immersed in one of the following three solutions: distilled water (control), CHX, or Listerine® for 2 min, once per day. We recorded the samples' baseline color values according to the CIELab system by using a color spectrophotometer operated by an experienced operator. Color measurements were subsequently obtained following 7 days of immersion, and after the samples were rinsed with distilled water and allowed to dry. We measured CIE L*, a*, and b*and calculated the color difference (ΔE*ab). All data were analyzed by the Mann-Whitney and Kruskal-Wallis tests. RESULTS: Color changes occurred in the experimental groups. The ΔE*ab values were significantly greater in VMK 95 porcelain compared to cube X2 (both p < 0.001) following immersion in CHX and Listerine® mouthrinses. However no significant difference was founded when distilled water was used (p = 0.630). For the two materials, the ΔE values were highest in CHX, followed by the Listerine® and distilled water. CONCLUSION: Both monolithic zirconia and feldspathic porcelain were susceptible to color changes following immersion in CHX and Listerine® mouthrinses.

Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures.

AIMS AND OBJECTIVES: Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran. MATERIALS AND METHODS: The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software. RESULTS: Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004). CONCLUSIONS: Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection.

Cone Beam Computed Tomographic Analysis of the Course and Position of Mandibular Canal.

PURPOSE: Estimation of the relative position of infra alveolar nerve (IAN) canal and its relation to the mandibular anatomical landmarks can be clinically useful in minimizing the risk of surgery complications such as neurosensory disturbances that may occur after invasive mandibular surgical procedures. The purpose of the present study was to investigate the anatomic location and radiographic course of the mandibular canal compared to anatomic landmarks on CBCT and to discuss its clinical significance and also to determine the possible correlations between the mandibular position and the age of the patients. METHODS: This cross sectional study was conducted on 242 CBCT of patients (99 males and 143 females). The location of canal was evaluated in 4 different regions. The first section in trans-axial view after mental foramen, in which the loop of mandibular canal is formed, was selected as point 1 for measurement and intervals of 10 mm, respectively, points 2, 3, 4 were selected for measurement. On these sections, the shortest linear distances (mm) from the most buccal and lingual aspects of the canal to the corresponding cortical plates of the mandible and also the minimum linear distance between the inferior aspect of canal and inferior border of mandible in these regions were calculated. RESULTS: There was statistically significant correlation between the anatomic course of the canal and the patients' gender. The mean vertical position of the canal, as measured from the lower border of the IAN canal to the inferior border of the mandible, was 8.50 mm, ranging from 4.80 to 14.50 mm. On average, the mandibular canal was situated more lingually at all sites to the point it reached the mental foramen. However, at the mental foramen region (Point 1), it was located closer to the buccal cortical plate. CONCLUSION: Assessment of the exact course of the IAN preoperatively along the body of the mandible by using CBCT might contribute to efficient and accurate surgical planning and therefore positively influence the surgical results. The results of this study confirm the necessity of using CBCT before invasive surgical procedures to determine the variations in the relative position and course of IAN canal.

Etiology, Diagnosis and Management of Oromandibular Dystonia: an Update for Stomatologists.

Oromandibular dystonia (OMD) is a rare focal neurological disorder that affects mouth, face, and jaws. This comprehensive literature review aimed to summarize the current evidence for etiology, diagnosis, and management of OMD and assess the possibility of dental origin of the disease and dental treatment plans for these patients. Different online databases namely PubMed, Google scholar, and Scopus were searched. The keywords "oromandibular dystonia", "orofaciomandibular dystonia", "orofacial-buccal dystonia", "lingual dystonia", "jaw dystonia", "cranial dystonia", and "adult-onset facial dystonia" were searched in the title and abstract of publications from 1970 to 2016. The inclusion criterion was the dental etiology and/or dental treatment. Out of 1260 articles, only 37 articles met the inclusion criteria. OMD can be caused or exacerbated through different dental treatments within which anyone is likely to be involved due to various reasons. Some novel methods employed to relieve this syndrome have led to certain cure or improvement of symptoms in several cases. OMD patients may refer to dentists with involuntary jaw movements and intraoral presentations. Thus, the dentists should be aware of the symptoms and signs and refer the suspicious cases. Dentists should also be familiar with special considerations when managing OMD patients.

The prevalence of pathologic tooth migration with respect to the severity of periodontitis.

AIM: Pathologic tooth migration (PTM) has been defined as tooth displacement that occurs when the balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease. The aim of this cross-sectional epidemiological study was to determine the prevalence of pathologic tooth migration among patients with periodontitis. MATERIALS AND METHODS: Recorded documents of 370 patients (72.4% females, 27.6% males) within the age range of 17 to 70 years (mean 37.77 ± 11.46) were studied. Statistical analysis was carried out using t-test and Chi-square test. RESULTS: Pathologic migration prevalence was 11.4% (35/314 patients), however, there was no pathologic migration in patients with mild chronic periodontitis. The Chi-square test showed that there was no statistically significant difference between males and females. CONCLUSIONS: The results of this study confirm that pathologic tooth migration is relatively common among periodontal patients and its prevalence is increased by the severity of periodontal disease.

In Vitro Evaluation of Bacterial Leakage at Implant-Abutment Connection: An 11-Degree Morse Taper Compared to a Butt Joint Connection.

Background and Aim. The geometry of implant-abutment interface (IAI) affects the risk of bacterial leakage and invasion into the internal parts of the implant. The aim of this study was to compare the bacterial leakage of an 11-degree Morse taper IAI with that of a butt joint connection. Materials and Methods. Two implants systems were tested (n = 10 per group): CSM (submerged) and TBR (connect). The deepest inner parts of the implants were inoculated with 2 µL of Streptococcus mutans suspension with a concentration of 108 CFU/mL. The abutments were tightened on the implants. The specimens were stored in the incubator at a temperature of 37°C for 14 days and the penetration of the bacterium in the surrounding area was determined by the observation of the solution turbidity and comparison with control specimens. Kaplan-Meier survival curve was traced for the estimation of bacterial leakage and the results between two groups of implants were statistically analyzed by chi-square test. Results. No case of the implant system with the internal conical connection design revealed bacterial leakage in 14 days and no turbidity of the solution was reported for it. In the system with butt joint implant-abutment connection, 1 case showed leakage on the third day, 1 case on the eighth day, and 5 cases on the 13th day. In total, 7 (70%) cases showed bacterial leakage in this system. Significant differences were found between the two groups of implants based on the incidence of bacterial leakage (p < 0.05). Conclusion. The 11-degree Morse taper demonstrated better resistance to microbial leakage than butt joint connection.

Periodontal Health Status among Patients with Behçet's Disease.

We aimed to evaluate the relationship of individual periodontal parameters with the severity of Behçet's disease (BD) and attempt to find the correlation between chronic periodontitis and BD. In this study, 74 registered subjects attending Behçet's clinic with BD symptoms were recruited. The diagnosis was based on the criteria presented by the international study group for BD (ISG) and the total clinical severity score was determined for each patient. All individuals underwent clinical examination to assess oral and periodontal status and presence of oral ulcers. Periodontal clinical parameters of bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) and also hygiene index (HI) and decayed, missing, and filled (DMF) teeth were noted and analyzed to assess the correlation with severity of BD. There was no significant correlation between DMF and severity of BD. The strong association was found between periodontal parameters (BOP, PD, and CAL) and the severity of BD (P < 0.001). It seems that relation of BD to oral health is higher up in severe forms of BD and periodontal diseases. Clinical association between the diseases might be due to a common underlying etiopathogenesis of periodontitis and BD.

Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes.

Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF) versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1) and the rest was used to get a membrane by PRGF-Endoret system (group 2). Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P < 0.05). The mean stiffness in group 1 was also higher but not statistically significant (P > 0.05). Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here.

In vitro comparison of cytotoxic and antibacterial effects of 16 commercial toothpastes.

BACKGROUND: Toothpastes are considered as one of the most common and usable cosmetic and hygienic materials. Such materials contain chemicals which may have an adverse effect on oral tissue in humans. The present study aimed to compare the toxic effect of current commercial toothpastes including Iranian products and imported types which are consumed globally on oral epithelial- and HeLa cells as well as to evaluate their antibacterial effect on Streptococcus mutans in Shiraz, Iran. MATERIALS AND METHODS: In this experimental study, 16 types of commercial toothpastes were prepared, and their effect was determined on primer epithelial cells of the oral cavity and HeLa cells. Toothpastes anti streptococcal property and toxicity were examined in vitro in different intervals of 1, 2, and 5 min. Data collection and analysis were done using one-way analysis of variance. RESULTS: All experimented toothpastes revealed variable toxic effects on cultured cells. Through an increase in the time of exposure with toothpastes, the toxicity of these materials substantially increased (P = 0.005). On the other hand, all tested toothpastes showed varying degrees of anti-streptococcal effect in the laboratory (P = 0.005). CONCLUSIONS: The most cytotoxic effect on primer epithelial cells of oral mucosa and HeLa cells, respectively, belongs to Bath, Daroogar2, Latifeh2, Crend, Sehat, Nasim and Aqua fresh toothpastes; however, the least cytotoxic effect on primer epithelial cells of oral mucosa and HeLa cells, respectively, belongs to Pronamel followed by Crest (sensitive), Close-up, Oral-B, Signal, Colgate, Paradent, and AME.

Use of lincomycin-impregnated demineralized freeze-dried bone allograft in the periodontal defect after third molar surgery.

PURPOSE: The aim of the present study was to evaluate the periodontal regenerative capacity of demineralized freeze-dried bone allograft (DFDBA) alone or used with local lincomycin. MATERIALS AND METHODS: In the present single-blind, randomized, controlled clinical trial, 20 subjects 26 years old or older, requiring extraction of bilateral third molars (M3s), were included. Each subject was randomly assigned to receive either DFDBA or DFDBA plus lincomycin therapy. Within the subjects, 1 M3 site was randomly selected to be the experimental site and the contralateral served as the control and was permitted to heal without intervention. The primary variables were changes in the probing depth (PD), clinical alveolar bone levels (ABLs), and radiographic alveolar bone density (ABD) on the distal aspect of second molar between baseline (immediately postoperatively) and 26 weeks postoperatively (T26). Appropriate sample sizes and descriptive, bivariate, and multivariate statistics were computed. RESULTS: For both treatment and control sites, between T0 and T26, statistically significant improvements were seen in the ABLs and ABD (P < .05). Within-subject comparisons showed no significant differences in PD, ABL, or ABD between the treatment and control M3 sites at T0 or T26 (P > .05). Also, no significant differences were found in the PD, ABL, or ABD between the 2 treatment M3 sites at T26 (P > .05). CONCLUSIONS: The results of the present study have revealed that the PD, ABL, and ABD improved after M3 removal in subjects 26 years old or older, irrespective of the treatment or control group. Reconstructive procedures (e.g., DFDBA with or without lincomycin therapy) did not offer predictable benefits compared with a no-treatment protocol in patients younger than 30 years old.

Effects of exposing dental implant to the maxillary sinus cavity.

The aim of this study was to evaluate the effects of exposing dental implants to the maxillary sinus cavity. This is a retrospective study. Thirteen patients with 18 implants that had radiographic evidence of implant exposure to the maxillary sinuses participated in this study. We evaluated the patient's radiographs immediately after implant insertion and 12 months after operation with the patient's clinical signs and symptoms due to sinusitis. Thirteen patients with 18 implants in the maxillary sinus had no signs and symptoms of sinusitis. Radiography showed thickening of the sinus membranes in 2 patients. All penetrated implants were successfully integrated, and there were no radiographic signs of bone loss or other complications.The exposure of implants to the maxillary sinuses caused no problems in the maxillary sinuses, and bone formation occurred in THE maxillary floor when penetration of maxillary sinuses occurred without tearing of the membrane.

Histological analysis of the effect of accelerated portland cement as a bone graft substitute on experimentally-created three-walled intrabony defects in dogs.

BACKGROUND AND AIMS: Recent literature shows that accelerated Portland cement (APC) is a non-toxic material that may have potential to promote bone healing. The objective of this study was to histologically evaluate periodontal healing focusing on new bone regeneration following implantation of APC into intra-bony defects in dogs. MATERIALS AND METHODS: Three-wall intra-bony periodontal defects were surgically created at the mesial aspect of the first molar in both sides of mandible in six dogs. One side was randomly filled with the material and other received a flap operation only. The animals were euthanized eight weeks post-surgery when block sections of the defect sites were collected and prepared for qualitative histological analysis. RESULTS: Compared to control group, stimulation of growth of new bone tissue in the cavity con-taining APC was significantly prominent in three of six cases, showing osteoid formation with osteoblastic rimming and new bone trabeculla. New bone formation was observed just close to cavity containing APC. Connective tissue proliferation and downgrowth of epithelium were signif-icantly less than those of control group. CONCLUSION: Our results are encouraging for the use of APC as a bone substitute, but more comprehensive study are necessary before warranting clinical use.