bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipopolysaccharide‐Mediated Enhancement of Bone Metabolism in Estrogen‐Deficient Mice
Authors: Fujita Sachiko , Kikuchi Takeshi , Sobue Takanori , Suzuki Mariyo , Koide Masanori , Noguchi Toshihide 
Published: November 2008

Background: Osteoporosis may be a risk factor in periodontal disease. However, biologic mechanisms explaining the apparent interaction between these two diseases have not been defined. It is well known that lipopolysaccharide (LPS) increases the resorption of alveolar bone. We hypothesized that LPS and estrogen deficiency have synergistic effects on bone metabolism and may lead to enhanced bone resorption.Methods: Eighty 8‐week‐old female ddY mice were divided into two groups and underwent a sham operation or bilateral ovariectomy. They were maintained for 4 weeks to assess estrogen‐deficient bone loss. Osteoblasts and bone marrow cells (BMCs) were collected from ovariectomized (OVX) and sham‐operated mice. Osteoclast differentiation in a coculture of osteoblasts and BMCs was investigated by tartrate‐resistant acid phosphatase staining. Receptor activator of nuclear factor‐kappa B ligand (RANKL) mRNA expression in LPS‐treated osteoblasts was investigated using real‐time polymerase chain reaction. Interferon‐gamma (IFN‐γ) and interleukin (IL)‐6 and −10 levels in the culture supernatants were evaluated by enzyme‐linked immunosorbent assay. Group means were compared by analysis of variance followed by Tukey's honestly significant difference.Results: There was a significant increase in the number of osteoclasts in LPS‐treated cocultures from OVX mice compared to sham controls (P <0.05). RANKL mRNA expression in LPS‐treated osteoblasts from OVX mice was greater than in sham mice (P <0.05). In contrast, the production of IFN‐γ in LPS‐treated coculture from OVX mice was significantly lower than in sham mice (P <0.05).Conclusion: LPS‐bearing Gram‐negative organisms are abundant in periodontal disease, and the results supported the hypothesis that bone resorption is increased in estrogen‐deficient patients.
Effect of Neurotrophin‐4/5 on Bone/Cementum‐Related Protein Expressions and DNA Synthesis in Cultures of Human Periodontal Ligament Cells
Authors: Mizuno Noriyoshi , Shiba Hideki , Inui Takafumi , Takeda Katsuhiro , Kajiya Mikihito , Hasegawa Naohiko , Kawaguchi Hiroyuki , Kurihara Hidemi 
Published: November 2008

Background: We studied neurotrophins (NTs) as signaling molecules for periodontal tissue regeneration and showed that nerve growth factor (NGF) and brain‐derived neurotrophic factor (BDNF) modulate the proliferation and differentiation of human periodontal ligament (HPL) cells in vitro. The purpose of this study was to investigate whether NT‐4/5 also has the ability to regulate the function of HPL cells.Methods: mRNA expressions of NT‐4/5 and its high‐affinity tyrosine kinase receptor (trk)B were analyzed in HPL cells by reverse transcription‐polymerase chain reaction. We examined how NT‐4/5 regulates the mRNA expression of bone/cementum‐related proteins (alkaline phosphatase [ALPase], osteopontin [OPN], osteocalcin [OC], and bone morphogenetic protein [BMP]‐2) in cultures of HPL cells. Moreover, the effects of NT‐4/5 on calcification, the production of OPN and OC, and DNA synthesis in HPL cells were examined.Results: NT‐4/5 and trkB mRNA were expressed in HPL cells. NT‐4/5 elevated the mRNA levels of ALPase, OPN, OC, and BMP‐2 and the syntheses of OPN, OC, and DNA in HPL cells. PD98059, an extracellular signal‐regulated kinase (ERK) inhibitor, obviated the increase in the mRNA levels of ALPase, OPN, OC, and BMP‐2. NT‐4/5 increased the levels of phosphorylated ERK1/2. Furthermore, NT‐4/5 enhanced the amount of mineral deposits in cultures of HPL cells.Conclusion: NT‐4/5, as well as BDNF and NGF, is suggested to play a role in the regulation of function of periodontal ligament cells.
Effects of Relapse Forces on Periodontal Status of Mandibular Incisors Following Orthognathic Surgery
Authors: Ari‐Demirkaya Arzu , Ilhan Isil 
Published: November 2008

Background: In this case‐control study, the relationship between the relapse forces and periodontal changes in the mandibular incisor region were investigated following orthognathic surgery.Methods: Mucogingival and alveolar changes in 36 subjects with mandibular prognathism were analyzed by clinical and roentgenographic methods just before mandibular setback surgery and 7.4 months postoperatively. The results were compared to two control groups: 36 subjects with no orthodontic history and 33 orthodontic patients. The mean age of the 105 subjects was 20.21 years.Results: The intergroup comparisons showed significant differences in all parameters, except for the plaque index and alveolar height measurements. By an incisor proclination of 3.3 mm and a tipping of +8.5° (postoperative relapse: 0.8 mm and 0.14°), the surgery group revealed significant changes in single parameters of both alveolar height and sulcus depth measurements.Conclusions: Compared to both control groups, the preoperative periodontal condition of the surgery patients was less acceptable than in the orthodontically treated patients, whereas subjects without braces presented the most ideal hygienic conditions. In the short term, the decompensation process prior to mandibular setback surgery did not affect periodontal structures significantly, and the current study did not find any negative effects of early postoperative relapse forces on the mandibular incisor area.
Clinical and Microbiologic Effects of Subgingivally Delivered 0.5% Azithromycin in the Treatment of Chronic Periodontitis
Authors: Pradeep A.R. , Sagar S. Vidya , Daisy Happy 
Published: November 2008

Background: Recent developments suggest that the local delivery of antimicrobials into periodontal pockets can improve periodontal health. The present study was undertaken to investigate the clinical and microbiologic effectiveness of azithromycin (AZM) at 0.5% concentration in an indigenously prepared bioabsorbable controlled‐release gel as an adjunct to non‐surgical mechanical therapy in the treatment of chronic periodontitis.Methods: Eighty patients were categorized into two treatment groups: scaling and root planing (SRP) only (group 1) and SRP plus 0.5% AZM (group 2). Clinical parameters were recorded at baseline and 1, 2, and 3 months; they included modified gingival index, modified sulcus bleeding index, probing depth (PD), and clinical attachment level (CAL). At baseline and 6 and 12 weeks, microbiologic assessment was done of the percentage of morphologically different microorganisms (coccoid cells, others [straight rods, filaments, and fusiforms], motile rods, and spirochetes) using darkfield microscopy. The mean concentration of 0.5% AZM in gingival crevicular fluid was estimated by reverse phase high performance liquid chromatography.Results: Both therapies resulted in significant improvements. Mean PD reduction from baseline to 3 months was 2.13 ± 0.35 mm and 2.53 ± 0.52 in groups 1 and 2, respectively. Mean CAL gain from baseline to 3 months was 0.60 ± 0.63 mm and 1.07 ± 0.70 mm in groups 1 and 2, respectively. All microbiologic categories showed significant improvement in both groups, with greater improvement in the test group. The mean concentration of AZM at all observed periods (baseline to 28 days) provided sufficient antimicrobial activity (>2 μg/ml) and fulfilled the conditions for a controlled‐release device.Conclusion: Although both treatment strategies seemed to benefit the patients, the adjunctive use of 0.5% AZM as a controlled drug‐delivery system enhanced the clinical and microbiologic results as shown by the intergroup comparison.
The Effect of Thick Mucosa on Peri‐Implant Tissues: An Experimental Study in Dogs
Authors: Jeong Seung‐Mi , Choi Byung‐Ho , Li Jingxu , Xuan Feng 
Published: November 2008

Background: Findings from animal studies have indicated that the implant–mucosal barrier consists of a junctional epithelium ∼2 mm long and a connective tissue compartment about 1 to 1.5 mm high. It may be argued that different features develop in the implant–mucosal barrier when it is placed within the alveolar bone with thick mucosa. The aim of this study was to examine the influence of a thick mucosa on peri‐implant tissue healing around dental implants.Methods: The bilateral fourth mandibular premolars and all maxillary premolars were removed in six mongrel dogs. On one side (test side) of the mandible, a standardized bone defect (8.0 mm in height) was created in the premolar region, whereas no defect was created on the other side (control side). After 3 months of healing, one implant was placed on each side of the mandible; a long abutment (12 mm in height) was connected to the fixture on the bone defect side, whereas a normal abutment was connected to the fixture on the control side. After a healing period of 6 months, all dogs were sacrificed to evaluate peri‐implant tissues.Results: The height of the mucosa, the length of the junctional epithelium, and the height of the zone of connective tissue integration were significantly greater in the thick mucosa than in the normal mucosa (P <0.05). No significant difference was found between the control and test sides in the marginal level of bone‐to‐implant contact.Conclusions: The junctional epithelium extended more apically in the thick mucosa than in the normal mucosa. However, additional marginal bone resorption was not observed at the thick mucosa sites.
Nifedipine Intake Increases the Risk for Periodontal Destruction in Subjects With Type 2 Diabetes Mellitus
Authors: Li Xiao , Luan Qingxian , Wang Xingyu , Sha Yueqin , He Lu , Cao Caifang , Jin Lijian 
Published: November 2008

Background: This study investigated the possible association of nifedipine (NIF) intake and diabetes mellitus (DM) with periodontal destruction.Methods: A group of Chinese subjects (N = 1,083, age: 63 ± 8.7 years) were screened. Three hundred fifty‐eight non‐smokers with hypertension were selected for the study and were grouped based on DM status as non‐DM and DM groups, DM(−) and DM(+) respectively. NIF(+) and NIF(−) indicated NIF intake or not. The groups were further divided: NIF(−)/DM(−) (n = 135); NIF(+)/DM(−) (n = 108); NIF(−)/DM(+) (n = 64); and NIF(+)/DM(+) (n = 51). The periodontal conditions in anterior teeth were assessed using plaque index, sulcus bleeding index, clinical attachment loss (AL), probing depth (PD), and the number of missing teeth.Results: Using analysis of covariance, NIF intake was associated with mean PD and extent of PD ≥4 mm in the non‐DM and DM groups. The subjects in the NIF(+)/DM(+) subgroup showed greater mean AL and percentage of sites with AL ≥5 mm and AL ≥7 mm than those in NIF(−)/DM(+) subgroup, whereas no significant difference existed between subjects in NIF(−)/DM(−) and NIF(+)/DM(−) subgroups. The NIF(+)/DM(+) subgroup exhibited a greater percentage of sites with AL ≥5 mm (35.5%) compared to the other three subgroups (24.7% for NIF[−]/DM[−], P = 0.004; 25.0% for NIF[+]/DM[−], P = 0.007; and 25.2% for NIF[−]/DM[+], P = 0.016). Logistic regression analysis showed that the NIF(+)/DM(+) subgroup had a significantly higher risk for having >10% of sites with AL ≥5 mm compared to the NIF(−)/DM(−) subgroup (odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.2 to 7.4; P = 0.022), the NIF(+)/DM(−) subgroup (OR = 3.1; 95% CI: 1.2 to 8.1; P = 0.020), and the NIF(−)/DM(+) subgroup (OR = 5.1; CI: 1.8 to 14.3; P = 0.002).Conclusion: NIF intake may increase the risk for periodontal destruction in patients with type 2 DM.
Treatment of Experimental Periodontal Disease by Photodynamic Therapy in Rats With Diabetes
Authors: de Almeida Juliano Milanezi , Theodoro Leticia Helena , Bosco Alvaro Francisco , Nagata Maria José Hitomi , Bonfante Samara , Garcia Valdir Gouveia 
Published: November 2008

Background: The aim of this study was to evaluate histologically and histometrically the influence of photodynamic therapy (PDT) as an adjuvant treatment on induced periodontitis in rats with diabetes.Methods: Two hundred forty rats were divided evenly into two groups: non‐diabetic (ND; n = 120) and alloxan diabetic (D; n = 120). Periodontal disease was induced in both groups at the first mandibular molar. After 7 days, the ligature was removed, and all animals underwent scaling and root planing (SRP) and were divided according to the following treatments: irrigation with saline solution (SRP); irrigation with a phenothiazinium dye (100 μg/ml) (TBO); laser irradiation (660 nm, 24 J) (LLLT); and PDT (TBO and laser irradiation). Ten animals in each experimental group and treatment subgroup were euthanized at 7, 15, and 30 days. The histometric values were analyzed statistically (P <0.05).Results: In the ND group, the animals treated by PDT showed less bone loss (0.33 ± 0.05 mm2, 0.35 ± 0.06 mm2, and 0.27 ± 0.07 mm2 at 7, 15, and 30 days, respectively; P <0.05) at all experimental periods than the SRP group (1.11 ± 0.11 mm2, 0.84 ± 0.12 mm2, and 0.97 ± 0.13 mm2 at 7, 15, and 30 days, respectively), the TBO group (0.51 ± 0.12 mm2, 0.70 ± 0.13 mm2, and 0.64 ± 0.08 mm2 at 7, 15, and 30 days, respectively), and the LLLT group (0.59 ± 0.03 mm2, 0.61 ± 0.04 mm2, and 0.60 ± 0.03 mm2 at 7, 15, and 30 days, respectively). In the D group, the animals treated by PDT showed less bone loss (0.29 ± 0.03 mm2, 0.24 ± 0.02 mm2, and 0.27 ± 0.06 mm2 at 7, 15, and 30 days, respectively; P <0.05) at all experimental periods than the SRP group (2.27 ± 0.47 mm2, 3.23 ± 0.34 mm2, and 2.82 ± 0.75 mm2 at 7, 15, and 30 days, respectively), the TBO group (0.51 ± 0.15 mm2, 0.44 ± 0.07 mm2, and 0.57 ± 0.13 mm2 at 7, 15, and 30 days, respectively), and the LLLT group (0.37 ± 0.05 mm2, 0.35 ± 0.09 mm2, and 0.39 ± 0.12 mm2 at 7, 15, and 30 days, respectively).Conclusion: PDT was a beneficial adjuvant treatment for periodontal diseases induced by bacterial plaque and systemically modified by diabetes mellitus.
Histomorphometric Analysis of Newly Formed Bone After Maxillary Sinus Floor Augmentation Using Ground Cortical Bone Allograft and Internal Collagen Membrane
Authors: Kolerman Roni , Tal Haim , Moses Ofer 
Published: November 2008

Background: Maxillary sinus floor augmentation is the treatment of choice when insufficient alveolar bone height prevents placement of standard dental implants in the posterior edentulous maxilla. The objective of this study was to histologically and histometrically evaluate new bone formation after maxillary sinus floor augmentation using ground cortical bone allograft.Methods: Mineralized freeze‐dried bone allograft (FDBA) was used for sinus floor augmentation. After 9 months, 23 biopsies were taken from 19 patients. Routine histologic processing using hematoxylin and eosin and Mallory staining was performed.Results: Histologic evaluation revealed a mean of 29.1% newly formed bone, 51.9% connective tissue, and 19% residual graft material. Graft particles were mainly in close contact with newly formed bone, primarily with features of mature bone with numerous osteocytes, and, to a lesser extent, with marrow spaces. There was no evidence of acute inflammatory infiltrate.Conclusion: FDBA is biocompatible and osteoconductive when used in maxillary sinus‐augmentation procedures, and it may be used safely without interfering with the normal reparative bone process.
The Association of Orthodontic Treatment and Fixed Retainers With Gingival Health
Authors: Levin Liran , Samorodnitzky‐Naveh Gili R. , Machtei Eli E. 
Published: November 2008

Background: The use of postorthodontic fixed retainers made of wire and composite resin bonded to the lingual/palatal tooth aspect is a common practice that can affect gingival health. The purpose of this study was to evaluate the association of orthodontic treatment and fixed retainers with gingival health.Methods: The study included 92 consecutive subjects who arrived for routine dental examination at a military dental clinic between May and August 2007. Plaque and gingival indices, gingival recession, probing depth, and bleeding on probing were measured at the anterior sextants. When a fixed retainer was present, the distance was measured between the retainer and incisal edge and to the cemento‐enamel junction. Past orthodontic treatment and smoking habits were self‐reported. Postorthodontic patients were sorted by the presence or absence of fixed retainers.Results: The mean probing depth was 1.90 ± 0.2 mm, and gingival recession was 0.06 ± 0.02 mm; 20.8% of all sites exhibited bleeding on probing. Current smoking was reported by 20 (21.7%) patients. Labial gingival recession was significantly greater in treated (0.13 ± 0.2 mm) patients compared to non‐treated patients (0.05 ± 0.2 mm; P = 0.03). Localized lingual gingival recession was significantly greater in teeth with fixed retainers (0.09 ± 0.2 mm) compared to teeth with no fixed retainers (0.01 ± 0.1 mm; P = 0.0002), as were plaque and gingival indices and bleeding on probing. Plaque on the lingual/palatal aspect showed a weak, positive correlation with lingual gingival recession (r = 0.16; P = 0.033).Conclusion: Orthodontic treatment and fixed retainers were associated with an increased incidence of gingival recession, increased plaque retention, and increased bleeding on probing; however, the magnitude of the difference in recession was of low clinical significance.
Immediate Loading of the Edentulous Maxilla With a Final Restoration Supported by an Intraoral Welded Titanium Bar: A Case Series of 20 Consecutive Cases
Authors: Degidi Marco , Nardi Diego , Piattelli Adriano 
Published: November 2008

Background: The aim of this prospective study was to evaluate the concept of intraoral welding as a suitable technique for the placement of a final restoration for the edentulous maxilla on the same day as surgery.Methods: Twenty patients with edentulous maxillae received a fixed restoration supported by an intraoral welded titanium bar. Final abutments were connected to the implants and welded to a titanium bar using an intraoral welding unit. This framework was used as a support for the final restoration, which was fitted on the same day as implant placement. Mean marginal bone loss and radiographically detectable alteration of the welded framework were assessed using periapical radiographs immediately after surgery and at 6‐ and 12‐month follow‐up examinations.Results: Ten males and 10 females, with an average age of 51.8 years (SD = 15.1 years; N = 20), were consecutively treated with 153 immediately loaded implants. No fractures or radiographically detectable alterations of the welded framework were evident. All implants osseointegrated and were clinically stable at the time of the 12‐month follow‐up. Mean marginal bone loss was 0.43 mm (SD = 0.13 mm; N = 153) between 0 and 6 months and 0.14 mm (SD = 0.055 mm; N = 153) between 6 and 12 months. Therefore, the accumulated mean marginal bone loss was 0.57 mm (SD = 0.21 m; N = 153).Conclusions: On the same day of surgery, it is possible to successfully rehabilitate the edentulous maxilla with a fixed, permanent prosthesis supported by an intraoral welded titanium framework. More expanded investigations over longer time periods are required to better determine the long‐term success of this approach.
Longitudinal Changes in Microbiology and Clinical Periodontal Variables After Placement of Fixed Orthodontic Appliances
Authors: van Gastel Jan , Quirynen Marc , Teughels Wim , Coucke Wim , Carels Carine 
Published: November 2008

Background: In the past few decades, more patients have been treated orthodontically, but no longitudinal study has compared orthodontic bands and brackets microbiologically and clinically.Methods: This longitudinal trial (split‐mouth design) included 24 patients. Microbiology (sub‐ and supragingival), probing depth (PD), bleeding on probing (BOP), and gingival crevicular fluid flow (GCF) were assessed at baseline (band placement) and at weeks 18 (bracket bonding) 20, 24, and 36. A statistical comparison was made over time and among the banded, bonded, and control sites.Results: The aerobe/anaerobe ratio of sub‐ and supragingival colony forming units decreased significantly (relatively more anaerobes) over the study period for the banded and bonded sites (P <0.001). This decrease was accompanied by significant elevations in PD, BOP, and GCF. These changes occurred faster after bonding compared to banding. No significant changes were observed 18 weeks after banding with the exception of increased PD (P <0.001). At week 36, all microbial and clinical variables at the bonded site had changed significantly in the negative direction (P <0.001) compared to week 18. The control sites did not show any significant changes over time, indicating that the effects were localized.Conclusions: The placement of fixed orthodontic appliances had a significant impact on microbial and clinical variables. The changes occurred faster at the bonded sites compared to the banded sites, probably because wire insertion caused difficulties in approximal cleaning. Over the long term, banding did not lead to more adverse microbial and periodontal effects than bonding.
Upregulation of Heme Oxygenase‐1 Expression in Gingiva After Cyclosporin A Treatment
Authors: Chiu Hsien‐Chung , Lan Guo‐Lun , Chiang Cheng‐Yang , Chin Yu‐Tang , Tu Hsiao‐Pei , Ming‐Jen Fu Martin , Shin Nieh , Fu Earl 
Published: November 2008

Background: Heme oxygenase (HO)‐1 is a stress‐inducible protein that confers cytoprotection, but its role in gingiva during cyclosporin A (CsA) therapy is unknown. We used in vivo and in vitro models to investigate the expression of mRNA and protein for HO‐1 in gingiva upon CsA treatment.Methods: Twenty‐six male Sprague‐Dawley rats were assigned to two groups after the establishment of edentulous ridges. Rats in the CsA group received CsA, 30 mg/kg/day for 4 weeks, whereas control rats received mineral oil only. All rats were killed after 4 weeks, and the edentulous gingivae were excised. mRNA and protein expression of HO‐1 in gingivae were determined using reverse transcription‐polymerase chain reaction (RT‐PCR) and immunohistochemistry (IHC), respectively. For the in vitro study, cultured human gingival fibroblasts were harvested after treatment with various concentrations of CsA, and HO‐1 mRNA and protein expression were determined using RT‐PCR and Western blotting, respectively.Results: Mean gingival HO‐1 mRNA expression was greater in the CsA group than in the control animals (P = 0.076). IHC staining for HO‐1 protein was significantly greater in the gingivae of CsA‐treated rats than in those of the control group. In fibroblast cultures, expression of HO‐1 mRNA and protein also increased significantly after CsA treatment.Conclusion: CsA upregulates the gingival expression of HO‐1, which may exert a cytoprotective effect.