bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Postsurgical Antibiotics and a Bioabsorbable Membrane on Regenerative Healing in Class II Furcation Defects
Authors: Vest Tracey M. , Greenwell Henry , Drisko Connie , Wittwer John W. , Bichara Jean , Yancey John , Goldsmith Jane , Rebitski George 
Published: February 2005

Background: The purpose of this randomized, controlled, blinded, clinical investigation was to determine the effect of postsurgical antibiotics on osseous healing in Class II furcation defects.Methods: Twenty‐four Class II furcation defects in 24 patients were treated with either a polylactide bioabsorbable membrane, demineralized freeze‐dried bone allograft (DFDBA) plus antibiotics (GBA or test group) or with a polylactide membrane and DFDBA alone (GB or control group). Twelve patients were included in each group. The antibiotic regimen consisted of ciprofloxacin 250 mg twice daily and metronidazole 250 mg tid for 1 week followed by a 7‐week regimen of doxycycline hyclate 50 mg daily. Treatment was performed on either mandibular buccal or lingual, or maxillary buccal Class II furcation defects. Defects were randomly selected by a coin toss for treatment and all open and closed measurements were performed by a blinded examiner. Final open and closed measures from a stent were repeated at the 9‐month second stage surgery. Power analysis to determine superiority of antibiotic treatment showed that a 12 per group sample size would yield 93% power to detect a 1.5 mm difference and 64% power to detect a 1 mm difference.Results: Mean open horizontal probing depth reductions at 9 months were greater for the GBA group than for the GB group (2.92 ±1.78 versus 2.50 ±1.62 mm); however, these differences were not statistically significant. Seven of 12 furcations (58%) in the GBA group demonstrated >50% vertical defect fill at 9 months compared to 8 of 12 furcations (67%) in the GB group. There were no significant differences in mean open horizontal probing depth reduction between smokers and non‐smokers in either the GBA or GB groups. Membrane exposure did not appear to affect regenerative healing in either the GBA or GB groups.Conclusions: The administration of postsurgical antibiotics did not produce statistically superior osseous healing of Class II furcation defects. This result may be attributable to membrane design which facilitates connective tissue ingrowth, thereby preventing bacterial downgrowth and contamination of the newly regenerated tissues. J Periodontol 1999;70:878‐887.
Resistance Profile Survey of 50 Periodontal Strains of Actinobacillus actinomycetemcomitans
Authors: Madinier Isabelle M. , Fosse Thierry B. , Hitzig Claude , Charbit Yves , Hannoun Lionel R. 
Published: February 2005

Background: Antibiotic resistance has been increasingly described among bacterial species colonizing periodontal pockets, particularly in Prevotella and Porphyromonas spp. strains producing β‐lactamases, and frequently associated with resistance to tetracycline and erythromycin. These resistance genes may be carried on motile genetic elements, or transposons, capable of interspecies and intergeneric transmission among bacterial strains colonizing a same ecological niche. The aim of this prospective study was to determine the resistance profile of Actinobacillus actinomycetemcomitans and the prevalence of A. actinomycetemcomitans strains producing β‐lactamases in periodontal pockets.Methods: Fifty strains of A. actinomycetemcomitans were isolated from 42 patients with adult periodontitis. No patient had periodontal or antibiotic therapy in the previous 6 months. Bacterial samples were collected from periodontal pockets ≥5 mm, appropriately diluted, inoculated onto selective medium (chocolate blood agar with bacitracin 75 μg/ml and vancomycin 5 μm/ml) and incubated for 5 days at 37°C in air with 5% CO2. After conventional identification, susceptibility testing to 11 antibiotics was performed by the broth dilution method, in trypticase soy broth supplemented with yeast extract, hemin, and 0.1% NaHCO3 to maintain microaerophilic conditions in the microtitration plate wells by CO2 formation.Results: No strain demonstrated resistance to amoxicillin, amoxicillin‐clavulanic acid combination, pristinamycin, or ciprofloxacin at the breakpoint, but 40% of the strains were slightly resistant to penicillin G, and 4% were resistant to erythromycin, 90% to spiramycin, 18% to clarythromycin, 4% to tetracycline, 72% to metronidazole, and 12% to ornidazole. Amoxicillin, followed by tetracycline and erythromycin, was the most effective antibiotic on A. actinomycetemcomitans. The phenotypic research of a β‐lactamase was negative for all the strains tested.Conclusions: In this work, most A. actinomycetemcomitans strains were resistant to metronidazole, but the amoxicillin‐metronidazole association may be of interest against subgingival anaerobic and capnophilic mixed flora. Pristinamycin and ciprofloxacin appeared as effective alternative monotherapies against A. actinomycetemcomitans. The threat of β‐lactam antibiotic resistance related to β‐lactamase production is currently not a problem with A. actinomycetemcomitans as it has been reported in oral anaerobes. J Periodontol 1999;70:888‐892.
Disposition of Alendronate Following Local Delivery in a Rat Jaw
Authors: Yaffe A. , Binderman I. , Breuer E. , Pinto T. , Golomb G. 
Published: February 2005

Background: Recently, we have shown that local delivery of alendronate reduced significantly bone resorption activated by surgical separation of periosteum from bone. These results advocate the use of local application of alendronate in bone surgeries to prevent regional bone resorption at the surgery site. Here we investigated the efficacy absorbtion of alendronate by the bone from a gelatin sponge soaked with radiolabeled alendronate applied topically at the surgical site.Methods: Following elevation of the mucoperiosteal flap next to premolars and molars of the rat mandible, a gelatin sponge soaked with 10 μl of radiolabled alendronate (1μCi/mg) was applied to exposed bone on one side. The local absorbtion of alendronate and its disposition in the contralateral side of the mandible as well as in the tibia bone were analyzed.Results: The results show that 10% of total alendronate content of the gelatin sponge was absorbed in the bone locally (in the surgical site), while 0.2% was disposed in the tibia. Of interest is the fact that the surgical wound in the contralateral side increased the disposition of alendronate up to 2%. This finding is most likely the result of extravasation and diffusion of alendronate due to surgical wounding.Conclusion: This study strongly supports our notion that local delivery of alendronate and its affinity to bone may become a very important treatment modality to prevent resorption of bone during dental and orthopedic procedures. J Periodontol 1999;70:893‐895.
Use of Bovine‐Derived Anorganic Bone Associated With Guided Tissue Regeneration in Intrabony Defects. Six‐Month Evaluation at Re‐Entry
Authors: Batista Eraldo L. , Novaes Arthur B. , Simonpietri C. Jeannette J. , Batista Felipe C. 
Published: February 2005

Background: Different filling materials have been associated with guided tissue regeneration (GTR) in order to improve its regenerative potential and predictability. Anorganic bovine bone (ABB) has demonstrated biocompatibility and osteoconductive properties; however, there are limited data regarding its performance in the treatment of intrabony defects. This investigation aimed to evaluate the clinical outcome of the association of anorganic bovine bone with cellulose membranes in intrabony defects after 6 months.Methods: Twenty‐six paired intrabony defects were selected from 11 non‐smoking patients with no relevant medical history. The defects were similar regarding the number of bony walls and defect depth, and presented pocket depths ≥ 6 mm. Four weeks after completion of basic therapy, probing depth (PD), clinical attachment level (CAL), and gingival margin position (GP) were recorded (baseline values). The defects were then surgically accessed and debrided, and the intrabony component measured to the nearest millimeter with periodontal probes and customized acrylic stents (distance from the stent to the base of the defect and from the stent to the alveolar crest). Each intrabony defect was randomly assigned to receive the membrane alone (control, C) or the membrane with anorganic bovine bone (test, T). The patients were re‐evaluated after 6 months, and re‐entry procedures were performed.Results: Significant (P <0.01) improvement in all variables was observed: mean pocket reduction of 4.61 ± 1.60 mm (C) and 4.46 ± 1.50 mm (T) and clinical attachment gain of 2.85 ± 1.46 mm (C) and 3.15 ± 1.40 mm (T); the difference between groups was not significant (P >0.05). Nevertheless, gingival recession in the control group (1.84 ± 0.89 mm) was significantly (P <0.05) more pronounced than that observed in the test group (1.30 ± 0.48 mm). Bone measurements indicated a significant resolution of the defects (P <0.01). A mean defect resolution of 2.76 ± 0.72 mm (C) and 2.69 ± 1.03 mm (T) and crestal resorption of 1.07 ± 0.64 mm (C) and 1.30 ± 0.85 mm (T) were detected (P >0.05). Stepwise multiple regression analysis indicated that for both groups, the baseline depth of the defects and the alveolar crest resorption accounted for 82% of the variability of bone fill observed in the control group (F = 23.65, P <0.001) and 89% in the test group (F = 41.32, P <0.001).Conclusions: ABB may be used in conjunction with GTR in the treatment of intrabony defects. Its use, however, did not result in a better outcome than the use of membranes alone. Studies employing more patients would be of interest in order to determine the advantages and indications of the tested approaches on a more predictable basis. J Periodontol 1999;70:1000‐1007.
Tetracycline‐Coated Polytetrafluoroethylene Barrier Membranes in the Treatment of Intraosseous Periodontal Lesions
Authors: Zarkesh Niloofar , Nowzari Hessam , Morrison John L. , Slots Jørgen 
Published: February 2005

Background: Periodontal pathogens are detrimental to periodontal healing in barrier membrane‐assisted periodontal therapy. Tetracycline‐coating of barrier membranes may reduce levels of infecting pathogens. This study evaluated the clinical and microbiological effects of tetracycline‐coated expanded polytetrafluoroethylene (T‐ePTFE) barrier membranes in the treatment of 2‐ to 3‐wall intraosseous periodontal lesions around mandibular molars.Methods: Eleven patients received non‐coated barrier membranes (ePTFE) and 11 patients received T‐ePTFE barrier membranes. Tetracycline coating was performed by placing ePTFE membranes first in a 5% tridodecylmethylammonium chloride solution and then in a basic 3% tetracycline solution. Microbiological examination included conventional culture and DNA probe analyses. Barrier membranes were removed 6 weeks after insertion.Results: At baseline, the periodontal lesion depth averaged 8.0 mm in the ePTFE treated group and 7.4 mm in the T‐ePTFE group. At 1 year post‐treatment, the mean gain of probing attachment was 1.9 mm in the ePTFE group and 3.3 mm in the T‐ePTFE group (P = 0.02). At 3 minutes after membrane placement, suspected periodontal pathogens were detected in several ePTFE membranes but only in one T‐ePTFE membrane. At 6 weeks, all membranes showed periodontal pathogens, including Porphyromonas gingivalis, Fusobacterium species, Peptostreptococcus micros, Bacteroides forsythus, and motile rods.Conclusions: This study suggests that the use of tetracycline‐coated ePTFE barrier membranes can result in additional gain of clinical periodontal attachment, most likely due to the antimicrobial properties of tetracycline during initial healing. J Periodontol 1999;70:1008‐1016.
Modulation of Androgen Metabolism by Estradiol‐17β and Progesterone, Alone and in Combination, in Human Gingival Fibroblasts in Culture
Authors: Tilakaratne A. , Soory M. 
Published: February 2005

Background: Androgens, particularly 5α‐dihydrotestosterone (DHT), have anabolic effects on connective tissues and bone with implications on periodontal healing. This can be enhanced by estradiol‐17β (E‐17β), in synergy with androgen action. The effects of progesterone (P) contribute to plaque‐induced inflammatory changes. The aim of this investigation was to study the modulation of androgen metabolism by E‐17β and P, alone and in combination.Methods: Human gingival fibroblasts were established in monolayer culture and duplicate incubations were performed in Eagle's MEM for 24 hours with either 14C‐testosterone (14C‐T) or 14C‐4‐androstenedione (14C‐4‐A) as substrate and serial concentrations of E‐17β, P and E‐17β + P. The medium was solvent extracted for steroid metabolites, analyzed, and quantified using a radioisotope scanner. The androgen substrates were converted mainly to DHT and 4‐androstenedione/testosterone from 14C‐T and 14C‐4‐A respectively.Results: At concentrations of 0.1 and 0.5 μg/ml, E‐17β stimulated DHT synthesis from 14C‐T by 18% and 12%, respectively, decreasing to control values at 0.1 μg/ml. While the effect of similar concentrations of P on the same substrates was inhibitory by 18, 70, and 82% (n = 4; P <0.01). E‐17β + P showed a 12% increase in DHT synthesis over controls at 0.1 μg/ml, similar to that of E‐17β alone, despite the inhibitory effects of P (n = 4; P <0.01) with 12% and 77% decreases at 0.5 and 1 μg/ml (n = 4; P <0.01). The inhibitory effect of P on DHT synthesis was less apparent when E‐17β was present in combination. The formation of 4‐androstenedione from 14C‐T was stimulated by E‐17β (12.5%), inhibited by P (50%) and showed an intermediate response with E + P (33% stimulation). At the concentrations used, E‐17β stimulated DHT synthesis from 14C‐4‐A by 3.6‐, 3‐ and 2.6‐fold. P also stimulated this conversion from the same substrate by 16%, 2‐fold, and 1.6‐fold increases, partly due to the low yields at baseline. The combination of E + P stimulated the synthesis of DHT from 14C‐4‐A by 4‐fold at 0.1 and 0.5 μg/ml and a 2.3‐fold increase at 1 μg/ml. The formation of T from 14C‐4‐A was stimulated by E‐17β (50%) and inhibited by P (40%), with 93% stimulation by E + P at 0.1 μg/ml.Conclusions: The modulatory effects of estradiol‐17β and progesterone on androgen metabolism may influence disease presentation and the progress of healing responses in the inflamed periodontium. J Periodontol 1999;70:1017‐1025.
Bone Regeneration by Recombinant Human Bone Morphogenetic Protein‐2 in Rat Mandibular Defects. An Experimental Model of Defect Filling
Authors: Higuchi Tatsuhiro , Kinoshita Atsuhiro , Takahashi Koichiro , Oda Shigeru , Ishikawa Isao 
Published: February 2005

Background: Bone defects and irregularities are major problems for dental implant and periodontal therapies.Methods: We investigated whether the application of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) induces bone formation in through‐and‐through bone defects in the rat mandible. A round through‐and‐through bone defect (5 mm in diameter) was created in the angle of the mandible on both sides of the jaw using a steel round bur in each of 8 Long‐Evans rats. In the experimental group, polylactic acid‐polyglycolic acid copolymer/gelatin sponge PGS) containing rhBMP‐2 (6 μg/60 μl) was inserted in the bone defect. In the control group, the same carrier without rhBMP‐2 was applied in the bone defect on the opposite side. Four weeks after application, the rats were sacrificed. Step serial sections stained with hematoxylin and eosin at intervals of 200 µm were prepared in a bucco‐lingual direction. The size of the bone defects and new bone formation were evaluated histometrically.Results: In all cases in the experimental group, a large quantity of newly formed bone was observed. The bone defects were completely filled with new bone in 4 of 8 rats in the experimental group. In the control group, small amounts of new bone formation were observed along the border of the original mandibular bone. Histometrical analysis revealed that the amount of new bone was significantly larger in the rhBMP‐2 treated sites than in the control sites (P <0.0001; paired t‐test).Conclusions: These results indicate that the rhBMP‐2/PGS system induced effective bone regeneration on mandibular defects in rats. This procedure may be suitable as an experimental model for bone regeneration using various growth factors and effective for alveolar ridge augmentation followed by dental implant surgery. J Periodontol 1999;70:1026‐1031.
Association of a Vitamin D Receptor Gene Polymorphism With Localized Early‐Onset Periodontal Diseases
Authors: Hennig Branwen J.W. , Parkhill Judith M. , Chapple Lain L.C. , Heasman Peter A. , Taylor John J. 
Published: February 2005

Background: Early‐onset periodontal diseases (EOP) are caused by interactions between host factors, specific microbial pathogens, and environmental factors. It is, therefore, of interest to investigate the nature of host factors as they may provide useful risk markers and reveal important information regarding the disease pathogenesis. Genetic polymorphisms in the vitamin D receptor (VDR) gene are associated with parameters of bone homeostasis and with diseases in which bone loss is a cardinal sign, in particular osteoporosis. Rapidly progressive bone loss is one feature of EOP. We, therefore, sought to determine whether EOP is associated with a polymorphism in the VDR gene.Methods: A restriction fragment length polymorphism (RFLP) for Taq I in exon nine of the VDR gene was analyzed by PCR, followed by restriction digestion with Taq I and gel electrophoresis. We analyzed the genotypes of 69 EOP patients, including 20 patients with unequivocal evidence of localized disease (L‐EOP), and 72 controls with no history of EOP.Results:The genotype distribution in the L‐EOP patient group was 7 (35%), 5 (25%) and 8 (40%) and in the control group 31 (43.1%), 36 (50.0%) and 5 (6.9%) for TT, Tt and tt respectively (where t and T represent the alleles with and without the Taq I RFLP respectively). χ2 analysis indicated that the distribution of the genotypes between these two groups was highly significantly different (P = 0.001). Allele frequencies were 47.5% and 52.5% for T and t in the L‐EOP group; 68.1% and 31.9% in the control group, showing a significant association between the prevalence of the less frequent allele (t) and L‐EOP (P = 0.017). There was no significant difference in the genotype distribution or the allele frequencies between the control samples and the larger EOP patient group (n = 69) which included patients with generalized and localized disease.Conclusions: These data indicate that carriage of the less frequent allele of the Taq I RFLP (t) in the VDR gene significantly increases the risk of developing L‐EOP. However, VDR genotype may not affect the incidence of all cases of EOP. These findings contribute to our understanding of the genetic basis for periodontal disease and may help define sub‐groups of this disease which share common pathogenic factors. J Periodontol 1999;70:1032‐1038.
N‐Cadherin Expression During Periodontal Ligament Cell Differentiation In Vitro
Authors: Lin Wen‐Lang , Chien Hua‐Hong , Cho Moon‐Il 
Published: February 2005

Background: When confluent periodontal ligament (PDL) cells were cultured in the presence of dexamethasone (Dex), ascorbic acid (AA), and β‐glycerophosphate (GP), they underwent sequential differentiation, demonstrating distinct morphological characteristics. At 1 week, localized cell proliferation led to the formation of multilayers of cells. As cell differentiation progressed, they formed nodules by deposition of matrix in the clusters of cells at 2 weeks, and mineralized the nodules at 3 weeks. These changes implicate extensive cell‐to‐cell interactions. Cadherins are known to play an important role in establishing cell contacts during tissue formation.Methods: To determine whether cadherins are involved in PDL cell differentiation, and the formation and mineralization of nodules by the cells in vitro, we investigated the expression of N‐cadherin using immunofluorescence labeling and Northern blot analysis.Results: Immunolabeling showed that N‐cadherin was expressed in PDL cells in the stages of nodule formation and mineralization. Northern blot analysis demonstrated a 3‐fold increase in the expression of N‐cadherin mRNA in the stages. However, neither E‐cadherin nor P‐cadherin was expressed.Conclusions: Our data suggest that N‐cadherin may play an important role in PDL cell differentiation and the formation of mineralized nodules by PDL cells. J Periodontol 1999;70:1039‐1045.
Effect of a Carbon Dioxide Laser on Periodontally Involved Root Surfaces
Authors: Misra Vivek , Mehrotra K.K. , Dixit J. , Maitra S.C. 
Published: February 2005

Background: The purpose of this in vitro study was to evaluate the effect of CO2 laser on the periodontally involved root surface, and to compare its efficacy with citric acid, EDTA and hydrogen peroxide in removal of root surface smear layer after root planing.Methods: The study was conducted on 50 periodontally involved single rooted human teeth with poor prognosis. Immediately after extraction the teeth were scaled and root planed with Gracey curets; 50 specimens were obtained from the proximal side of each tooth which were assigned randomly to 1 of the 4 groups. Group A (35 specimens) was divided into 7 subgroups of 5 specimens each and irradiated with CO2 laser using a defocused mode at 3‐watt power for 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, or 1.4 seconds, respectively. Groups B, C, and D (5 specimens each) were treated with 6% hydrogen peroxide, EDTA solution (pH 7.4), or saturated citric acid solution (pH 1), respectively for 3 minutes. The specimens were then fixed and scanned using SEM.Results: It was observed that surface smear layer was present on root surfaces of teeth that were root planed; the CO2 laser was not able to remove the smear layer on the sites that were irradiated for 0.2, 0.4 or 0.6 seconds at 3W power. Irradiation time of 0.8 seconds at 3W power was able to remove the smear layer, but the dentinal tubules were partially exposed. The surface irradiated for 1 second showed a flat appearance with many clear orifice of dentinal tubules. No change in diameter of exposed dentinal tubules was observed and their diameter was nearly equal that of normal dentinal tubules. Irradiation time of 1.2 and 1.4 seconds produced surface charring and carbonization and was totally ineffective in exposing the dentinal tubules; 6% hydrogen peroxide did not remove the smear layer completely and the exposed dentinal tubules orifice was not clear. EDTA (pH 7.4) and citric acid (pH 1) were found to be effective in removing the smear layer and exposing the dentinal tubules, which showed funnel shaped widening.Conclusions: Surface smear layer was present on root surfaces of teeth that were root planed. Laser irradiation of 1 second at 3W completely removed the smear layer with minimal change in the diameter of the dentinal tubules. EDTA and citric acid were also effective in removing smear layer, but the exposed dentinal tubules showed funnel‐shaped widening. J Periodontol 1999;70:1046‐1052.