bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of 2.94 µm Er:YAG Laser Radiation on Root Surfaces Treated In Situ: A Histological Study
Authors: Folwaczny Matthias , Benner Klaus‐Ulrich , Flasskamp Barbara , Mehl Albert , Hickel Reinhard 
Published: February 2005

Background: Previous scanning electron microscopy (SEM) studies using extracted teeth have shown the potential of infrared Er:YAG laser radiation to remove subgingival calculus without causing severe thermal changes, e.g., charring or fusion, to the irradiated root surface. The purpose of the present study was to examine the morphologic changes on root surfaces following Er:YAG laser irradiation in situ using histological observation.Methods: The periodontal pockets of 6 premolars, canines, and incisors that remained in situ in the jaws of human corpses were irradiated with Er:YAG laser radiation at 60 mJ, 100 mJ, or 180 mJ. The pockets were treated in a similar manner to normal clinical circumstances with a total amount of either 50 or 100 laser pulses. Following laser treatment, the entire tooth, marginal gingiva, and underlying alveolar bone were removed from the jaw. The sections were embedded in methyl‐methacrylate, serially cross‐sectioned, stained with hematoxylin and eosin or gallamine blue, and examined under a light microscope. Additionally, the extension of the thermally changed tissue areas was determined using digital images and histometry.Results: The histological examination revealed two kinds of thermal changes within the laser‐treated root surface. Firstly, a thin superficial layer 5 to 10 µm in width was observed. The surface of this layer showed ultrastructural irregularities. Secondly, a semicircular more deeply stained area close to the apical end of the scaling track beneath the irradiated cementum was observed. The depth of this area ranged from 255 µm to 611 µm and appeared to be independent of the radiation energy.Conclusion: In contrast to previous SEM studies, the histological examination indicated thermal changes within the hard tissue bordering the periodontal pocket following Er:YAG laser irradiation. J Periodontol 2003;74:360‐;365.
The Influence of Nacre Surface and Its Modification on Bone Apposition: A Bone Development Model in Rats
Authors: Bahar Hila , Yaffe Avinoam , Binderman Itzhak 
Published: February 2005

Background: Bone graft substitutes are currently used individually or in various combinations in reconstructing bone defects. Nacre, marine mineralized structure, was recently proposed as a very biocompatible and osteoinductive material for use in periodontal and implant surgery. Our aim was to investigate the interaction between natural nacre and fresh bone marrow, during bone development, in an ectopic site of DA rats. Surface modifications of nacre were tested.Methods: Demineralized bone matrix (DBM) cylinders (demineralized cortex of diaphysis) prepared from rat femurs were filled with fresh marrow, which was removed from other 2‐month old DA rat femurs. Natural nacre particle or nacre which was treated with HCl, phosphate buffer saline (PBS), and Ca(OH)2 to modify its surface was placed into the DBM cylinders. The cylinders were implanted subcutaneously at the thoracic region of growing DA rats. After 4 weeks the cylinders were surgically removed, fixed in buffered formalin, and x‐rayed. Scans of the microradiographs and histological evaluation of the DBM cylinders including bone developed at the interface of nacre and its surface modifications were compared to marrow controls.Results: The results show that natural nacre is a poor conductive biomaterial in a bone developmental environment. Nacre surface treated with Ca(OH)2 and PBS was found to be most biocompatible. In this group, new bone was apposed directly on the nacre surface and the total amount of bone was highest in comparison to other treatment groups.Conclusions: This study does not support previous observations that nacre is osseoinductive. Our model system seems to be very sensitive and capable of testing interaction between surface modifications of biomaterials and fresh marrow in the process of new bone development. J Periodontol 2003;74:366‐371.
Clinical Outcome Observed in Subjects with Recurrent Periodontal Disease Following Local Treatment with 25% Metronidazole Gel
Authors: Jansson H. , Bratthall G. , Söderholm G. 
Published: February 2005

Background: The aim of this study was to evaluate the clinical outcome in patients with recurrent periodontal disease following treatment with 25% metronidazole gel.Methods: Twenty subjects in a maintenance care program but with recurrent periodontal disease participated. Three months after scaling and root planing, a total of 40 sites, 2 in each patient, with probing depth ≥5 mm were selected. One site randomly selected was treated with metronidazole gel (test) and the other site with a placebo gel (control). Baseline and follow‐up measurements included plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL).Results: There were no statistically significant differences in PI, GI, BOP, PD, or CAL between test and control sites.Conclusion: This study showed that local treatment with 25% metronidazole gel did not seem to influence the clinical healing in this group of subjects with recurrent periodontal disease. J Periodontol 2003;74:372‐377.
Permeability and Morphology of Dentin after Erosion Induced by Acidic Drinks
Authors: Prati Carlo , Montebugnoli Lucio , Suppa Pietro , Valdrè Giovanni , Mongiorgi Romano 
Published: February 2005

Background: The aims of this study were to evaluate 1) the alterations of dentin permeability after single exposure of dentin to several acidic soft drinks with different acid composition; 2) the effectiveness of smear layer on dentin surface to prevent erosion of sound dentin; and 3) the role of brushing procedures.Methods: Dentin discs from human third molars were prepared. Each disc was treated with 0.5 M neutral EDTA for 5 minutes to remove the smear layer and to calculate the maximum fluid flow rate for each disc (to which an arbitrary value of 100% was assigned) using a pressure apparatus working at 1.0 psi. An homogeneous thin smear layer was then recreated with an abrasive paper under water. The following acidic drinks were applied for 5 minutes onto dentin surface: cola drink (phosphoric acid), orange fruit juice (ascorbic + citric acid), white wine (tartaric acid), vinegar (acetic acid), and mucolytic syrup (benzoic and tartaric acid). Each sample was then brushed for 3 minutes. Finally, each sample was brushed with a toothpaste and, as the final step, etched with phosphoric acid for 1 minute. Permeability was measured after each step.Results: All acidic drinks were able to statistically increase dentin permeability and to open dentinal tubules by removing the smear layer.Conclusions: The study demonstrated that acidic drinks increased dentin permeability by removing and dissolving the smear layer and smear plugs. The erosion of peritubular dentin and smear plug removal is the main agent responsible for the increase in dentin permeability and probably for clinical dentin hypersensitivity. Brushing procedures reduced dentin permeability, creating a new fine and thin smear layer. Toothpaste may play a protective role in preventing complete smear layer removal and reducing dentin hypersensitivity by producing a new artificial smear layer and deposit inside tubules. The use and the abuse of acidic drinks may damage dentin and increase the risk for dentin hypersensitivity. J Periodontol 2003;74:428‐436.
Transforming Growth Factor‐Beta 1 Expression in the Peri‐Implant Soft Tissues of Healthy and Failing Dental Implants
Authors: Cornelini Roberto , Rubini Corrado , Fioroni Massimiliano , Favero Gian Antonio , Strocchi Rita , Piattelli Adriano 
Published: February 2005

Background: Transforming growth factor‐beta (TGF‐β) is composed of a family of multifunctional polypeptide growth factors involved in embryogenesis, inflammation, regulation of immune response, angiogenesis, wound healing, and extracellular matrix formation. TGF‐β1 is the most common isoform found in human tissues. A role of TGF‐β in the pathogenesis of periodontal disease has been suggested. The aim of the present study was a comparative immunohistochemical evaluation of TGF‐β1 in normal keratinized gingiva and in the peri‐implant soft tissues surrounding failing non‐submerged implants.Methods: Twenty patients participated in this study. Ten biopsies from healthy keratinized mucosa and 10 biopsies from periimplant soft tissues surrounding failing implants were obtained (one biopsy per patient). The biopsies were obtained from different patients.Results: In 5 cases of healthy mucosa, the stromal cells were positive between 1 to 5. In 7 cases, the epithelial layers were positive, between 1 and 18 cells. The superficial epithelial layer was negative in all cases. In 9 cases, there was a positivity of the vascular component, between 2 and 16 vessels. In failing implants, the stromal cells were positive in 6 cases, between 1 and 4. In all cases, cells of the epithelial layers were positive, between 15 and 40. The vascular component was positive in all cases, between 12 and 30 vessels. The differences between TGF‐β1 expression in the epithelium around healthy and failing implants were statistically significant (P<0.0001). The differences between TGF‐β1 expression in the blood vessels in the soft tissues around healthy and failing implants were also statistically significant (P <0.0001). No statistically significant difference was observed between the 2 groups in the TGF‐β1 expression in the stromal cells (P = 0.88).Conclusion: TGF‐β1 may be one of the most important factors in the regulation of the infiltrate, and in the production of tissue repair with a stimulation of fibroblasts and endothelial cells. J Periodontol 2003;74:446‐450.
Surgical Crown Lengthening: Evaluation of the Biological Width
Authors: Lanning Sharon K. , Waldrop Thomas C. , Gunsolley John C. , Maynard J. Gary 
Published: February 2005

Background: Previous surgical crown lengthening studies have investigated positional changes of the free gingival margin but not the biological width. Histological studies utilizing animal models have shown that postoperative crestal resorption allowed reestablishment of the biological width. However, very little work has been done in humans. Therefore, the purpose of this study was to evaluate the positional changes of the periodontal tissues, particularly the biological width, following surgical crown lengthening in human subjects.Methods: Twenty‐three (23) patients who needed surgical crown lengthening to gain retention necessary for prosthetic treatment and/or to access caries, tooth fracture, or previous prosthetic margins entered the study. The following parameters were obtained from line angles of treated teeth (teeth requiring surgical crown lengthening) and adjacent teeth with adjacent and non‐adjacent sites: plaque and gingival indexes, free gingival margin, probing depth, attachment level, bone level, direct bone level, and biological width. During surgery, the bone level was reduced based on the future prosthetic margin and predetermined biological width; flaps were placed at the bony crest. Patients were examined at baseline and at 3 and 6 months postoperatively.Results: Eighteen patients completed the study. Overall, the amount of bone resected was 1 to 5 mm. At 90% of treated sites, ≥3 mm of bone was removed. At 3 months, the apical displacement of the free gingival margin at non‐adjacent, adjacent, and treated sites was 2.46 ± 0.25 mm, 2.68 ± 0.20 mm, and 3.07 ± 0.16 mm, respectively. There was no significant change in the position of the free gingival margin from 3 to 6 months. The biological width at all sites was smaller at 3 and 6 months compared to baseline (P<0.05) except for the treated sites, which were not significantly different from baseline at 6 months.Conclusions: During surgical crown lengthening, the bone level was lowered for placement of the prosthetic margin and reestablishment of the biological width. The biological width, at treated sites, was reestablished to its original vertical dimension by 6 months. In addition, a consistent 3 mm gain of coronal tooth structure was observed at the 3‐ and 6‐month examinations.J Periodontol 2003;74:468‐474.
Mutations of F110 and C126 of the Formyl Peptide Receptor Interfere with G‐Protein Coupling and Chemotaxis
Authors: Jones Barbara E. , Miettinen Heini M. , Jesaitis Algirdas J. , Mills John S. 
Published: February 2005

Background: Localized aggressive periodontitis (LAgP) is a disease characterized by rapid loss of alveolar bone in teeth of otherwise healthy patients. Neutrophils from LAgP patients have been shown to exhibit diminished chemotaxis and low levels of formyl peptide receptor (FPR) surface expression. A recent study has associated LAgP with 2 polymorphisms in the FPR: 110Phe→Ser and 126Cys→Trp.Methods: We transfected Chinese hamster ovary cells with wtFPR, FPR‐110Phe→Ser, FPR‐126Cys→Trp, or FPR‐110 Phe→Ala and determined their surface expression of FPR, their ligand binding affinity, their G‐protein coupling, and their chemotaxis toward N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP).Results: FPR‐110Phe→Ser mutants failed to show any significant surface expression or chemotaxis toward FMLP. FPR‐126Cys→Trp mutants exhibited slightly lower than normal binding affinity, markedly lower G‐protein coupling response, and markedly lower chemotaxis toward FMLP than that observed with wtFPR. We also analyzed another FPR‐Phe110 mutant, FPR‐110Phe→Ala, to ascertain what the effect of mutating this residue might be in a mutant that could be expressed on the cell surface. The FPR‐110Phe→Ala mutant demonstrated markedly lower surface expression, normal ligand binding affinity, markedly lower G‐protein coupling, and markedly lower chemotaxis toward FMLP.Conclusions: Our data substantiate the hypothesis that the chemotactic defects observed in LAgP patients are due at least in part to molecular alterations in the FPR. The FPR‐110Phe→Ser polymorphism appears to be more defective than the FPR‐126Cys→Trp polymorphism, indicating that patients with the former polymorphism might be expected to exhibit a more severe form of aggressive periodontitis. J Periodontol 2003; 74:475‐484
A Pilot Study on Antiplaque Effects of Mastic Chewing Gum in the Oral Cavity
Authors: Takahashi Keiso , Fukazawa Munemoto , Motohira Hitoshi , Ochiai Kuniyasu , Nishikawa Hirofumi , Miyata Takashi 
Published: February 2005

Background: Chemical plaque control is a useful aid in mechanical oral hygiene, and various chemical agents have been evaluated as antiplaque agents. It has been shown that mastic chewing gum has antibacterial effects on Helicobacter pylori. In this study, the antiplaque effect of mastic chewing gum was investigated.Methods: Twenty dental students who were both systemically and periodontally healthy participated in this study. The effects of mastic gum were assessed from 2 double‐blinded, randomized studies. In the first trial, after mechanical toothbrushing, the inhibitory effect of mastic gum on bacteria in saliva following its use was compared to a placebo gum. Saliva samples were collected at the end of 1, 2, 3, and 4 hours; diluted; inoculated onto 10% horse blood chocolate agar plates; and cultured anaerobically at 37°C for 48 hours. The total number of bacterial colonies on each plate was calculated (n = 20). In the second trial, the effects of mastic gum on de novo plaque formation on tooth surfaces and gingival inflammation were evaluated over a 7‐day period without mechanical oral hygiene following random use of either mastic or placebo chewing gum. The degree of plaque accumulation and gingival inflammation were compared between the 2 groups (n = 10).Results: The total number of bacterial colonies was signifi‐cantly reduced during the 4 hours of chewing mastic gum compared to the placebo gum (P<0.05, Student t test). The mastic group showed a significantly reduced plaque index (2.69 ± 0.29 versus 3.15 ± 0.24; P = 0.001, Student t test) and gingival index (0.44 ± 0.15 versus 0.66 ± 0.23, P = 0.021, Student t test) compared to the placebo group.Conclusion: These results suggest that mastic chewing gum is a useful antiplaque agent in reducing the bacterial growth in saliva and plaque formation on teeth. J Periodontol 2003;74:501‐505.
Evaluation of p53, bcl‐2, and Interleukin‐15 Levels in Gingival Crevicular Fluid of Cyclosporin A‐Treated Patients
Authors: Buduneli Eralp , Genel Ferah , Atilla Gül , Kütükçüçler Necil 
Published: February 2005

Background: Apoptosis plays an important role in the maintenance of tissue homeostasis. Considering that apoptosis mediators may play a role in the pathogenesis of drug‐induced gingival overgrowth, this study was conducted to evaluate p53, bcl‐2, and interleukin‐15 (IL‐15) levels in gingival crevicular fluid (GCF) of cyclosporin A (CsA)‐treated patients.Methods: Twenty renal transplant patients exhibiting CsA‐induced gingival overgrowth and 15 systemically healthy gingivitis patients were included in the study; 15 systemically and periodontally healthy volunteer subjects served as the healthy control group. GCF samples were obtained from one interdental site with gingival overgrowth (GO+) and one site without (GO–) from each CsA‐treated patient; hyperplasia index, probing depth, papilla bleeding index, and plaque presence were recorded. One site from each gingivitis patient and healthy control was selected, GCF samples were obtained, and the same clinical parameters were recorded. GCF p53, bcl‐2, and IL‐15 levels were analyzed by enzyme‐linked immunosorbent assay. The results were tested statistically.Results: p53 and bcl‐2 levels were below the minimum detectable level in all GCF samples analyzed. CsA GO+ and CsA GO– sites, as well as gingivitis sites, exhibited significantly higher GCF levels of IL‐15 compared to healthy controls (P <0.05). The difference between CsA GO+ sites and gingivitis sites was not statistically significant, although the total amount of IL‐15 in CsA GO+ sites was lower than gingivitis sites (P >0.05). The total amount of IL‐15 in CsA GO– sites was significantly lower than gingivitis sites (P <0.05). No significant correlation was found between the clinical parameters and GCF IL‐15 levels (P>0.05).Conclusions: The pathogenesis of CsA‐induced gingival overgrowth is multifactorial. The findings of the present study indicate that IL‐15 may play a role in the pathogenesis of CsA‐induced gingival overgrowth due to its interactions with CsA and its role in apoptosis and inflammation. J Periodontol 2003;74:506‐511
Reliability of Clinical Attachment Level Recordings: Effects on Prevalence, Extent, and Severity Estimates
Authors: López Rodrigo , Retamales Carolina , Contreras Carolina , Montes José L. , Marín Alejandro , Væth Michael , Baelum Vibeke 
Published: February 2005

Background: Although unreliability of periodontal measurements is considered mainly to concern attempts to detect true changes in longitudinal studies, it is also a source of variability that may substantially decrease the precision of estimates obtained in cross‐sectional studies. This study assessed the effects of measurement errors on estimates of prevalence, extent, and severity of clinical attachment loss.Methods: Four examiners performed repeat attachment level recordings in 128, 122, 134, and 133 adolescents, respectively, who participated in a study of clinical attachment loss among 9,162 high school students from Santiago, Chile. A total of 48,954 duplicate recordings were made. Two examiner teams carried out repeat examinations among 292 and 254 subjects, respectively, corresponding to a total number of 51,600 duplicate recordings for interexaminer reliability assessment.Results: A sizeable imprecision was noted regarding prevalence estimates, particularly at the ≥1 mm level, whereas examiners were reasonably consistent in the assessment of the number of sites with clinical attachment loss. Ninety‐five percent of the differences regarding the number of sites with clinical attachment loss ≥1 mm were in the range from –5 to 5 sites for intraexaminer comparisons, and from –9 to 8 sites for interexaminer comparisons. These differences should be seen in light of the number of sites affected, which ranged from 0 to 85 sites.Conclusions: Examiner variation may preclude comparisons of prevalence estimates between studies. Valid comparisons may be made between studies of extent estimates provided that uniform parameters are used to express the extent of periodontal breakdown. J Periodontol 2003;74:512‐520.
Peri‐Implant Soft Tissue Integration of Immediately Loaded Implants in the Posterior Macaque Mandible: A Histomorphometric Study
Authors: Siar Chong Huat , Toh Chooi Gait , Romanos George , Swaminathan Dasan , Ong Ah Hup , Yaacob Hashim , Nentwig Georg‐Hubertus 
Published: February 2005

Background: Today, one critical goal in implant placement is the achievement of optimal soft tissue integration. Reports thus far have demonstrated successful soft tissue preservation in delayed loaded implants placed in anterior jaws. The aim of this study was to histomorphometrically examine the soft tissues around immediately loaded implants placed in the macaque posterior mandible.Methods: Splinted crowns on screw‐shaped titanium implants (8 mm length, 3.5 mm diameter) were utilized. Three implants each were placed in the premolar‐molar edentulous mandibular segments of 6 adult monkeys (Macaca fascicularis); one side served as the control (delayed loading) and the other as the test sites (immediate loading). The animals were sacrificed after 3 months of loading. Histomorphometry of 6 soft tissue indices including the sulcus depth (SD), junctional epithelium (JE), connective tissue contact (CTC), biologic width (BW = SD + JE + CTC), DIM (distance between the implant top and coronal gingiva), and DIB (distance between the implant top and first implant‐to‐bone contact) was performed on nondecalcified sections.Results: No significant differences in the mean soft tissue scores (mm) between the test (SD = 0.68 ± 0.63; JE = 1.71 ± 1.04; CTC = 1.51 ± 1.14; DIM = 2.27 ± 1.18; DIB = 1.32 ± 1.21; BW = 3.9) and control (SD = 0.88 + 0.57; JE = 1.66 + 0.77; CTC = 1.24 ± 0.92; DIM = 2.38 ± 0.81; DIB = 1.19 ± 0.91; BW = 3.78) groups were observed (P >0.01).Conclusion: These findings suggest that the dimensions of the peri‐implant soft tissues were within the biologic range and were not influenced by immediate functional loading or posterior location of the implants in the macaque mandible. J Periodontol 2003;74:571‐578.