bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spreading of Epithelial Cells on Machined and Sandblasted Titanium Surfaces: An In Vitro Study
Authors: Di Carmine Maristella , Toto Paola , Feliciani Claudio , Scarano Antonio , Tulli Antonello , Strocchi Rita , Piattelli Adriano 
Published: February 2005

Background: The purpose of this investigation was to determine the influence of the surface structure of dental implants on epithelial cell spreading and growth in vitro. Cell morphology on machined and sandblasted titanium surfaces was investigated.Methods: A total of 10 machined and 10 sandblasted discs and 10 glass coverslips were used for the present study. Samples were analyzed using scanning electron microscopy (SEM) and the cell spreading area was determined using a video image analysis system.Results: After 24 hours incubation, keratinocytes grown on sandblasted titanium samples displayed numerous, long, and branched or dendritic filopodia closely adapted to the surface roughness. Filopodia varied from 3 to 12 µm in length and 0.1 to 0.3 µm in width. Cells cultured on a machined surface did not present such cytoplasmic extensions and displayed a round morphology. Keratinocytes seeded on glass coverslips were flat and edged by filopodia (maximum length 7 to 8 µm) on the spreading site of the cluster. Though cell morphology is comparable with that observed on sandblasted specimens, cytoplasmic extensions suggestive of strong adhesion and spreading attitude were less pronounced.Conclusion: These results indicate that sandblasted surfaces are the optimal substrata for epithelial cell adhesion and spreading. J Periodontol 2003;74:289‐295.
Effect of Transforming Growth Factor‐β1, Interleukin‐6, and Interferon‐γ on the Expression of Type I Collagen, Heat Shock Protein 47, Matrix Metalloproteinase (MMP)‐1 and MMP‐2 by Fibroblasts from Normal Gingiva and Hereditary Gingival Fibromatosis
Authors: Martelli‐Junior H. , Cotrim P. , Graner E. , Sauk J.J. , Coletta R.D. 
Published: February 2005

Background: Increased collagen and extracellular matrix deposition within the gingiva is the main characteristic feature of hereditary gingival fibromatosis (HGF). To date, it is not well established if these events are a consequence of alterations in the collagen and other extracellular matrix molecules synthesis or disturbances in the homeostatic equilibrium between synthesis and degradation of extracellular matrix molecules. Cytokines are important regulators of expression of the profibrogenic genes, including type I collagen and its molecular chaperone heat shock protein (Hsp)47 and proteolytic enzymes degrading extracellular matrix such as matrix metalloproteinases‐1 and ‐2 (MMP‐1 and MMP‐2).Methods: In this study, we analyzed the expression and production of type I collagen, Hsp47, MMP‐1, and MMP‐2 in normal gingiva (NG) and HGF fibroblasts, and investigated the effects of transforming growth factorbeta1 (TGF‐β1), interleukin‐6 (IL‐6) and interferon‐gamma (IFN‐γ) on the expression of these genes by NG and HGF fibroblasts.Results: Our results obtained from semi‐quantitative reverse transcription‐polymerase chain reactions (RTPCR), Western blots, enzyme‐linked immunosorbent assays (ELISA), and enzymographies clearly demonstrated that the expression and production of type I collagen and Hsp47 were significantly higher in fibroblasts from HGF than from NG, whereas MMP‐1 and MMP‐2 expression and production were lower in fibroblasts from HGF patients. Addition of TGF‐β1 and IL‐6, which are produced in greater amounts by HGF fibroblasts, promoted an increase in type I collagen and Hsp47 and a decrease in MMP‐1 and MMP‐2 expression. IFN‐γ reduced both type I collagen and Hsp47 expression, whereas it had a slight effect on the expression of MMP‐1 and MMP‐2.Conclusion: These patterns of expression and production suggest that enhanced TGF‐β1 and IL‐6 production simultaneously increase the synthesis and reduce the proteolytic activities of fibroblasts from patients with HGF, which may favor the accumulation of extracellular matrix observed in patients with this condition. J Periodontol 2003;74:296‐306.
Association of Increased Levels of Fibrinogen and the –455G/A Fibrinogen Gene Polymorphism with Chronic Periodontitis
Authors: Sahingur Sinem E. , Sharma Ashu , Genco Robert J. , De Nardin Ernesto 
Published: February 2005

Background: Fibrinogen is one of the acute‐phase proteins whose levels are elevated during periodontal disease. Recent studies suggest that excessive fibrinogen production might play a role in upregulating host immune responses. In addition, there is a relationship between the –455G/A polymorphism (HaeIII) in the 5′ flanking region of the β‐fibrinogen gene promoter and increased fibrinogen levels. In this study, we investigated the distribution of the –455G/A polymorphism and the relationship of this specific genotype to fibrinogen levels in periodontitis patients.Methods: In order to assess the –455G/A polymorphism, restriction fragment length polymorphism (RFLP) analysis with HaeIII enzyme was performed in the promoter region of the β‐fibrinogen gene. This was carried out on 79 chronic periodontitis patients as compared to 75 periodontally healthy subjects, matched to age, gender, and race. Fibrinogen levels were determined by the radial immunodiffusion assay (RID).Results: The frequency of homozygocity for the rare allele of the β‐fibrinogen gene (H2H2) was 13% for the periodontitis patients and 3% for the control group (P = 0.01). The distributions of H1H1 and H1H2 genotypes were 48% and 39% in the patient group and 70% and 27% in the control group, respectively. Chisquare analysis indicated that the distribution of these genotypes between the 2 groups was significantly different (P = 0.01). Fibrinogen levels were significantly higher in the patient group (2,496.5 mg/l ± 105) compared to the control group (2,250.0 mg/l ± 118.3) after adjusting for age, gender, and smoking status (P = 0.04). Consistent with previous reports, in our study population, those subjects with the H2H2 genotype had significantly higher fibrinogen levels (3,005.7 mg/l ± 182.5) compared to subjects with the H1H1 genotype (2,325.0 mg/l ± 91.6) or H1H2 genotype (2,438.0 mg/l ± 117.4) (P = 0.001). Furthermore, the H1H2 and H2H2 genotypes were found at a higher frequency among periodontitis patients than controls. The odds ratios (OR) for these genotypes were 3.26 (95% confidence interval [CI]: 1.25 to 8.53) for the H1H2 genotype and 6.41 (95% CI: 1.15 to 35.83) for the H2H2 genotype as compared to individuals with the H1H1 genotype, after adjusting for age, gender, and smoking status.Conclusions: The results indicate that a higher percentage of chronic periodontitis patients exhibit genotypes associated with higher plasma fibrinogen levels than healthy individuals. Furthermore, periodontitis patients have significantly higher fibrinogen levels compared to healthy individuals. The presence of H1H2 or H2H2 genotypes as well as elevated fibrinogen levels, in conjunction with other factors, may put individuals at higher risk of having periodontal disease, or may result from periodontal infection‐genetic interactions. J Periodontol 2003;74:329‐337.
Role of the Microgap Between Implant and Abutment: A Retrospective Histologic Evaluation in Monkeys
Authors: Piattelli Adriano , Vrespa Giuseppe , Petrone Giovanna , Iezzi Giovanna , Annibali Susanna , Scarano Antonio 
Published: February 2005

Background: It has been hypothesized that a certain width of the peri‐implant mucosa is required to enable a proper epithelialconnective tissue attachment and, if this soft tissue dimension is not adequate, bone resorption will occur to ensure the establishment of attachment with an appropriate biological width. The reason for the accelerated bone loss around submerged 2‐piece implants in the first year after the restoration is not known, but one possibility is that the gap between components plays a role in this process. Recent studies have shown that for all 2‐part implants, the bone crest level changes appeared dependent on the location of the microgap.Methods: The aim of the present study was a retrospective histologic evaluation in monkeys of the bone response to implants inserted 1 to 2 mm above the alveolar crest (group 1, 15 implants), at the level of the alveolar crest (group 2, 12 implants), or 1 to 1.5 mm below the alveolar crest (group 3, 13 implants). These implants had been early loaded, immediately loaded, and inserted immediately postextraction.Results: In group 1, a 0.13 ± 0.12 mm bone increase in a coronal direction was seen. In group 2, a 2.1 ± 0.29 mm vertical bone loss was present. In group 3, a mean 3.6 ± 0.46 mm vertical bone loss extending in an apical direction was observed. Statistically significant differences were observed between all 3 groups.Conclusions: Our results confirm data published previously that if the microgap was moved coronally away from the alveolar crest, less bone loss would occur and if the microgap was moved apical to the alveolar crest, greater amounts of bone resorption were present. This remodeling is not dependent on early and immediate loading of the implants or on immediate postextraction insertion. J Periodontol 2003;74:346‐352.
β‐Glucuronidase Activity in Saliva: Relationship to Clinical Periodontal Parameters
Authors: Lamster Ira B. , Kaufman Eliaz , Grbic John T. , Winston Leslie J. , Singer Robert E. 
Published: February 2005

Background: β‐glucuronidase (βG) in gingival crevicular fluid (GCF), a marker of neutrophil influx into the crevicular environment, has previously been shown to be correlated with periodontal clinical parameters at individual sites (probing depth and clinical attachment level). Furthermore, elevated levels of βG were found to be a risk factor for periodontal attachment loss. Analysis of βG in saliva may be a measure of crevicular neutrophil influx for the whole mouth. The purpose of this cross‐sectional study was to evaluate the relationship between βG activity in saliva and periodontal clinical parameters in subjects demonstrating various levels of periodontal disease.Methods: The study population consisted of 380 subjects (108 males and 272 females). A sample of unstimulated whole saliva and a venous blood sample were obtained from each subject, and a periodontal examination, which included measurement of probing depth (PD), attachment level (AL), and gingival index (GI) was performed. The unmodified saliva samples were frozen at –20°C and analyzed for βG activity. The blood samples were analyzed for number of white blood cells, neutrophils, monocytes, lymphocytes, and platelets. Statistical analysis was conducted to determine the association between salivary βG activity and the whole‐mouth clinical periodontal parameters, complete blood count, smoking status, and age.Results: Highly significant correlations between salivary βG activity and mean probing depth (MPD), mean gingival index (MGI), and the number of sites with probing depth ≥5 mm were found. When subjects were divided into tertiles based on their MPD and MGI, elevated salivary βG activity was detected in subjects in the 2 upper tertiles. Logistic regression modeling was used to determine which of the clinical or laboratory parameters were able to identify patients with at least 4 sites with PD ≥5 mm. Salivary βG activity ≥100 produced an odds ratio (OR) of 3.77. In comparison, current and former smokers had an OR of 3.15 and 2.29, respectively.Conclusions: The results suggest that a significant association exists between periodontal clinical parameters and salivary βG activity. Due to the non‐invasive and simple nature of saliva collection, this association should be studied to determine its usefulness as a screening test for periodontitis, and a means of monitoring the response to treatment. J Periodontol 2003;74:353‐359.
Immediate Implants Covered with Connective Tissue Membranes: Human Biopsies
Authors: Wilson Thomas G , Carnio João , Schenk Robert , Cochran David 
Published: February 2005

Background: Osseointegration has been shown to occur around implants placed immediately after tooth extraction in humans. To date, such osseointegration has been achieved only with titanium plasma‐sprayed (TPS) implants placed in extraction sockets with a bone‐to‐implant distance of less than 2 mm. In a previous report, when this horizontal defect dimension (HDD) exceeded 2 mm, the resulting percentage of bone‐to‐implant contact was reduced, indicating that the immediate technique would be limited in most cases to non‐molar teeth. In an attempt to improve the bone‐to‐implant contact and the initial bone‐toimplant contact in a vertical dimension, the implant surface, the type of membrane, and the method of membrane placement used in a previous study by our group were modified.Methods: Ten large‐grit sandblasted, acid‐attacked (SLA) titanium implants were placed into immediate extraction sites in 5 patients. HDDs of 0.0 to 1.5 mm (controls), 1.5 to 4.0 mm, and >4.0 mm were used. Following insertion, implants were completely covered with a connective tissue membrane. This was in contrast to the use of an expanded polytetrafluoroethylene (ePTFE) membrane penetrated by the neck of the implant in our previous report. Primary closure of soft tissue flaps was achieved in each case. Six months after placement, 7 of the implants were histologically examined.Results: Osseointegration occurred across all HDDs, with the percentage of bone‐to‐implant contact in the 0.0 to 1.5 mm HDDs similar to that seen in the >4.0 mm HDDs. The first bone‐to‐implant contact measured vertically was similar in both the smaller and larger HDDs.Conclusions: Osseointegration was successful in immediate implant placement sites with horizontal defect dimensions wider than 4 mm in humans when SLA titanium implants were completely covered with connective tissue membranes. It remains undetermined whether the different type of membrane, placement of the membrane, type of implant surface, or a combination of these 3 factors were responsible for the improved osseointegration in HDDs >4 mm. Further study is needed. J Periodontol 2003;74:402‐;409.
Probing Depth Changes Following 2 Years of Periodontal Maintenance Therapy Including Adjunctive Controlled Release of Chlorhexidine
Authors: Soskolne W. Aubrey , Proskin Howard M. , Stabholz Ayala 
Published: February 2005

Background: Multicenter clinical trials have established that the adjunctive use of the subgingival controlled release of chlorhexidine, (CHX chip), significantly reduces probing depth (PD), improves clinical attachment levels, and reduces bleeding on probing compared to scaling and root planing (SRP) alone for periods of up to 9 months. The present report is based on a phase IV clinical trial to examine the adjunctive use of the CHX chip for routine periodontal maintenance therapy (RPMT) over 2 years.Methods: Eight hundred thirty‐five (835) patients were recruited into the study. At baseline a CHX chip was placed in pocket sites with PD≥5 mm. The patients were scheduled to receive RPMT at 3‐month intervals with repeated CHX chip placement at sites where the PD remained ≥5 mm. Patients who did not attend the 24‐month recall visit or who failed to attend 2 consecutive time frame examinations were excluded from the analyses.Results: The 595 patients included showed a continuous decrease in PD over 2 years of 0.95 mm. After 2 years, 23.2% of patients had at least 2 pockets showing a reduction in PD of 2 mm or more and 58.9% of the sites had been reduced to a PD of <5 mm. Only 2.9% (n=57) of the sites showed an increase in PD of ≥2 mm. Adverse events were mild to moderate in nature and resolved spontaneously without medication.Conclusion: The results of this Phase IV or follow‐up trial indicate that the adjunctive use of the CHX chip is a clinically safe and effective treatment option for long‐term management of chronic periodontitis. J Periodontol 2003;74:420‐427.
The Putative Collagen‐Binding Peptide P‐15 Promotes Fibroblast Attachment to Root Shavings but Not Hydroxyapatite
Authors: Lallier Thomas E. , Palaiologou Archontia A. , Yukna Raymond A. , Layman Don L. 
Published: February 2005

Background: Regenerative periodontal treatment aims to restore the attachment of the periodontal ligament and gingival collagen fibers to both the cementum of the root surface and alveolar bone. Fibroblasts are the predominant cells of the periodontal ligament and gingiva and have important roles in the function and regeneration of the tooth‐supporting apparatus. This study investigated whether a putative collagen‐based cellbinding peptide (P‐15) increases gingival fibroblast attachment to root shavings and bone replacement graft (BRG) materials.Methods: Gingival and dermal fibroblast attachment to root shavings and BRG materials, and cell proliferation on root shavings and sections were measured fluorometrically. Root shavings and root sections obtained from periodontally healthy teeth were treated with P‐15 at 2 concentrations (200 ng/g or 400 ng/g). Citric acid (CA)‐treated root materials were also compared to untreated root shavings and root sections that served as negative control groups.Results: Attachment of all cells to bone fragments (whether freeze‐dried or demineralized) was significantly greater than to hydroxyapatite (HA)‐based BRG materials. The addition of P‐15 to HA did not significantly increase gingival or dermal fibroblast attachment. At a concentration of 400 ng/g, P‐15 significantly increased gingival and dermal fibroblast attachment to root shavings as compared to untreated shavings. Bone fragments, HA‐based BRG materials, and untreated root shavings inhibited gingival fibroblast proliferation. Treatment of root sections with P‐15 did not have any effect on gingival fibroblast proliferation.Conclusions: P‐15 is a potential alternative to CA for promoting fibroblast attachment to root surfaces. However, P‐15 did not enhance fibroblast proliferation on root sections. J Periodontol 2003;74:458‐467.
The Influence of Gingival Margin Recession on Loss of Clinical Attachment in Alcohol‐Dependent Patients without Medical Disorders
Authors: Khocht Ahmed , Janal Malvin , Schleifer Steven , Keller Steven 
Published: February 2005

Background: The objective of this study was to examine the effects of alcohol and cocaine misuse on periodontal status in a group of alcohol‐dependent patients.Methods: Forty verified alcoholics, either exclusively (n = 10) or with cocaine abuse (n = 30), and a matched comparison group of 25 non‐alcoholic subjects, 14 of whom abused cocaine, were entered in the study. All subjects were free from systemic illnesses. Blood levels of gamma glutamyl transpeptidase (GGTP), a liver enzyme indicator of alcohol drinking, were determined. A comprehensive periodontal examination was performed on 6 sites per tooth. The gingival index (GI) and plaque index (PI) were recorded. Attachment levels (AL) were computed as probing depth (PD) plus gingival margin level (GM).Results: No statistically significant differences were noted between the groups for average AL, PD, GM, GI, and PI. In alcoholics, Pearson correlation showed a positive association between GGTP levels and loss of periodontal attachment (P <0.05). A series of regression analyses predicting AL from selected periodontal and demographic factors showed that alcoholics manifest AL by greater increases in GM than non‐alcoholics (P <0.07). Severe alcohol use as measured by GGTP >51 iu/l worsens PI (P <0.07), which adversely impacts GM, GI, PD, and ultimately AL. No significant associations were found between cocaine use and AL.Conclusions: The results suggest that persistent alcohol abuse increases periodontitis development by heightening the loss of attachment through recession of gingival margins. J Periodontol 2003;74:485‐493.
Membrane Type (MT)1‐Matrix Metalloproteinase (MMP) and MMP‐2 Expression in Ligature‐Induced Periodontitis in the Rat
Authors: Achong Ron , Nishimura Ichiro , Ramachandran Hema , Howell Thomas H. , Fiorellini Joseph P. , Karimbux Nadeem Y. 
Published: February 2005

Background: Matrix metalloproteinases (MMPs) have been shown to be involved in the degradation of the extracellular matrix (ECM). In particular, MMP‐2 and MMP‐9 (gelatinase A and gelatinase B, respectively) have been identified as the predominant MMPs during periodontitis. Recent studies have indicated that a novel transmembrane MMP, mebrane‐type 1 matrix metalloproteinase (MT1‐MMP), can activate pro‐MMP‐2 in tumor metastasis. This study aims to elucidate the presence and localization of MT1‐MMP and MMP‐2 in periodontitis in a rat model. Methods: In 2 groups of 40‐day‐old male Sprague‐Dawley rats, periodontitis was initiated by ligating floss around maxillary second molars. A group of control animals were left untreated. Maxillary dentoalveolar segments were isolated after 7 and 21 days postinduction and were prepared for gross and radiographic analysis of bone loss and for histological analysis. Samples were also prepared for gel zymography to detect the presence of MMP‐2, and for Northern blot analysis and in situ hybridization with MT1‐MMP probes.Results: MMP‐2 expression increased at 21 days following ligature placement, in conjunction with MT1‐MMP expression. MT1‐MMP mRNA expression was observed in epithelial cells, fibroblasts, and in multinucleated cells in the periodontium.Conclusion: Our data suggest that MT1‐MMP may play a role in extracellular matrix degradation during periodontitis, in concert with MMP‐2 and other proteinases. J Periodontol 2003;74: 494‐500.
The Segmental Osteotomy in the Management of Malposed Implants: A Case Report and Literature Review
Authors: Kassolis James D. , Baer Marvin L. , Reynolds Mark A. 
Published: February 2005

Background: The segmental osteotomy provides an important treatment approach for the correction of skeletal‐dental malocclusions that would otherwise be unmanageable with conventional orthodontic care. The combined use of orthodontics and orthognathic surgery also has been adapted for use in the correction of developmental and traumatic deformities. Severely malpositioned implant fixtures may not permit restorative correction even with custom prosthetic appliances. As an alternative to implant removal, which can be associated with significant alveolar destruction, orthognathic surgery may offer a treatment modality to improve fixture alignment, thereby enabling a more favorable esthetic and functional prosthesis. This paper presents a case report and review of the segmental osteotomy procedure.Methods: A 32‐year‐old female with congenitally missing maxillary lateral incisors underwent implant surgery for prosthetic replacement of these teeth. Due to severe labial positioning of the implant fixtures, acceptable prosthetic treatment was not possible. A segmental osteotomy procedure was used to reposition the implants. The implants were splinted using a ridged interim suprastructure during the 4‐month healing period. An occlusal appliance also was worn during the initial 8 weeks of this healing period.Results: The surgical procedure permitted intrusion and palatal repositioning of the implants. Healing proceeded with no untoward effects. Clinical findings at second‐stage surgery were consistent with complete osseous repair and integration of the fixtures. Successful prosthetic treatment was subsequently completed for the patient.Conclusion: The segmental osteotomy may provide an alternative treatment to the removal of severely malposed implants or their compromised prosthetic restoration J Periodontol 2003;74:529‐536.