IGF-I, IGF-IR and IRS1 expression as an early reaction of PDL cells to experimental tooth movement in the rat

Objective

To characterize in vivo the role of IGF-I and its signalling, as an early reaction in the mechanotransduction process and to analyse changes of the local expression related to the magnitude of the applied force.

Materials and methods

Forces of 0.1 N, 0.25 N and 0.5 N were applied to move the right upper first molars of 12 anaesthetized rats mesially. These forces were kept constant for 4 h. The untreated contralateral side served as a control. Paraffin-embedded sections of the resected jaws were prepared for immunohistochemistry to localize insulin-like growth factor-I (IGF-I), its receptor (IGF-IR), and insulin receptor substrate 1 (IRS1). Histomorphometric analysis was performed to count the percentage of immunoreactive cells in different parts of the periodontal ligament.

Results

IGF-I, IGF-IR and IRS1 positive cells were observed in the periodontal tissues of the control and loaded teeth. In the experimental group, the number of IGF-I-, IGF-IR- and IRS1-positive cells increased significantly on the tension side and decreased on the compression side.

Conclusions

These data indicate a close relationship between mechanical loading of the PDL and the autocrine/paracrine expression of IGF components as an early step in the mechanotransduction process leading in the long term to an organized remodelling of the alveolar bone.     

Association between mannose-binding lectin levels and gene polymorphisms in chronic periodontitis and response to treatment

Background

The aims of the present study were: (1) to investigate mannose-binding lectin (MBL) gene exon-1 polymorphisms in Turkish subjects with chronic periodontitis (CP), (2) to assess the association between these polymorphisms and plasma MBL levels, (3) to determine the effects of MBL genotypes on the outcomes of non-surgical periodontal therapy.

Methods

A total of 172 subjects were included in the present study. Genomic DNA was obtained from the peripheral blood of 83 CP patients and 89 periodontally healthy subjects. The MBL levels were measured by enzyme-linked immunosorbent assay (ELISA). The MBL gene exon-1 polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

Subjects homozygous for the frequent allele A had higher MBL plasma levels compared with rare allele B carriers. This difference in MBL plasma levels was statistically significant both in CP patients and healthy subjects. The distribution of MBL gene codon 54 genotypes and allele frequencies did not differ significantly between study groups. All study subjects were the MBL gene codon 52 and 57 frequent allele A carriers. Codon 54 B allele carriers had similar clinical periodontal parameters compared with AA genotypes after non-surgical periodontal therapy.

Conclusions

The present study failed to find any significant association between the MBL gene codon 54 polymorphisms and severe CP in a Turkish population. MBL gene rare allele carriers had lower MBL plasma levels in both study groups. It seems that MBL gene codon 54 B allele carriage may not influence the outcome of periodontal therapy.     

Angiotensin-converting enzyme (ACE), angiotensinogen (AGT), and angiotensin II type 1 receptor (AT1R) gene polymorphisms in generalized aggressive periodontitis

Aim

Host response to periodontopathic microorganisms can be modulated by genetic factors. Accumulated evidence highlighted the role of renin-angiotensin system (RAS) in inflammatory response thus potential implication of this molecular system in the pathogenesis of periodontitis can be suggested. The present study investigated common genetic variants of molecules within the RAS family namely angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type 1 receptor (AT1R) in relation to generalized aggressive periodontitis (G-AgP).

Methods

DNA was obtained from peripheral blood of 103 G-AgP patients and 100 periodontally healthy subjects. ACE I/D, AGT M235T and AT1R A1166C polymorphisms were genotyped by polymerase chain reaction and restriction fragment length polymorphism method. Chi-square, ANOVA and logistic regression were used in statistical analyses.

Results

Both ACE I/D and AT1R polymorphisms were similar in G-AgP and healthy groups (p > 0.05). G-AgP subjects exhibited decreased AGT TT genotype and T allele frequency as compared to healthy subjects (p < 0.05). The same trend was also observed in the nonsmoker subgroup regarding investigated RAS polymorphisms.

Conclusions

Present findings suggest that AGT M235T TT genotype and T allele might be associated with decreased risk for G-AgP in Turkish population.     

Recurrent aphthous stomatitis and Helicobacter pylori

Background

Recurrent aphthous stomatitis (RAS) is a recurrent painful ulcerative disorder that commonly affects the oral mucosa. Local and systemic factors such as trauma, food sensitivity, nutritional deficiencies, systemic conditions, immunological disorders and genetic polymorphisms are associated with the development of the disease. Helicobacter pylori (H. pylori) is a gram-negative, microaerophile bacteria, that colonizes the gastric mucosa and it was previously suggested to be involved in RAS development. In the present paper we reviewed all previous studies that investigated the association between RAS and H. pylori.

Material and Methods

A search in Pubmed (MEDLINE) databases was made of articles published up until July 2015 using the following keywords: Helicobacter Pylori or H. pylori and RAS or Recurrent aphthous stomatitis.

Results

Fifteen experimental studies that addressed the relationship between infection with H. pylori and the presence of RAS and three reviews, including a systematic review and a meta-analysis were included in this review. The studies reviewed used different methods to assess this relationship, including PCR, nested PCR, culture, ELISA and urea breath test. A large variation in the number of patients included in each study, as well as inclusion criteria and laboratorial methods was observed. H. pylori can be detected in the oral mucosa or ulcerated lesion of some patients with RAS. The quality of the all studies included in this review was assessed using levels of evidence based on the University of Oxford’s Center for Evidence Based Medicine Criteria.

Conclusions

Although the eradication of the infection may affect the clinical course of the oral lesions by undetermined mechanisms, RAS ulcers are not associated with the presence of the bacteria in the oral cavity and there is no evidence that H. pylori infection drives RAS development. Key words:Campylobacter, elisa, h. pylori, Helicobacter Pylori, RAS, recurrent aphthous stomatitis, PCR.     

Long-term evaluation of submerged and nonsubmerged ITI solid-screw titanium implants: a 10-year life table analysis of 468 implants

Purpose

Submerged and nonsubmerged ITI solid-screw titanium implants were followed retrospectively from 1989 to 1993 and prospectively from 1994 on to analyze long-term prognosis in partially and fully edentulous patients.

Material and Methods

A total of 468 implants were consecutively inserted in 191 patients from 1989 to 1998. Two hundred twenty-eight successfully integrated fixed-restoration implants and 238 with removable restorations were restored following a healing period of 4 to 6 months (9 months in sinus floor elevation sites). From 1994 on all implants inserted were documented annually up to 9 years. During examination the clinical status of the implants was analyzed and evaluated according to predefined criteria of success and this allowed the calculation of 10-year cumulative survival and success rates for 468 implants.

Results

Two implants (0.43%) did not successfully integrate during the healing period, and 8 implants (1.7%) were classified as failures during follow-up (1 late failure under load, 7 with a progressive bone loss from 1 to 3 threads). Including 68 implants in subjects who dropped out (with a dropout rate of 14.4%), the 10-year cumulative survival and success rates were 99.2% and 96.4%, respectively.

Discussion

Over the course of this long-term study, osseointegrated implants, once used as a last possible solution, became nearly standard in cases of single-tooth implants because of the high rate of long-term success. Life table analysis not only determines whether an implant is functioning, it also makes a statement about its clinical status according to strict success criteria.

Conclusion

The study demonstrated that ITI solid-screw titanium implants achieved success rates above 95% in a clinical center for an observation period of up to 10 years.—Reprinted with permission of Quintessence Publishing.     

Reliability of preoperative planning of an image-guided system for oral implant placement based on 3-dimensional images: an in vivo study

Purpose

The purpose of this study was to assess the reliability of the planning software of an image-guided implant placement system based on a mechanical device coupled with a template stabilized on soft tissue during surgery.

Materials and methods

Thirty consecutive partially or completely edentulous patients were treated with the image-guided system. For each patient, a study prosthesis was fabricated and duplicated in acrylic resin and served as a scanning template. Axial images were obtained from a computerized tomographic scan and transferred to planning software that provides real 3-dimensional information to plan implant position. Once the final position of the implant was defined, preoperative data such as the size of implants and anatomic complications were recorded using the planning software. The scanning template was then drilled in that exact position by a drilling machine. During surgery, the drilled template was used as a drill guide. After implant placement, intraoperative data were recorded and statistically compared with the preoperative data using the Kendall correlation coefficient for qualitative data and the Kappa concordance coefficient for quantitative data.

Results

Agreement between the preoperative and intraoperative data was high for both implant size and anatomic complications. The Kendall correlation coefficient was 0.8 for the diameter and 0.82 for the length. The Kappa concordance coefficient was 0.87 for both dehiscence and bone graft, 0.88 for osteotomy, and 1.0 for fenestration.

Discussion

In the few instances where planning was not perfect, implant placement was completed in a clinically acceptable manner.

Conclusion

The results suggest that the image-guided system presented is reliable for the preoperative assessment of implant size and anatomic complications. It may also be reliable for flapless surgery.—Reprinted with permission of Quintessence Publishing.     

Stimulated saliva flow rate patterns in children: A six-year longitudinal study

Objective

To find out whether the stimulated saliva flow rate (SSFR) is a variable and unpredictable characteristic as healthy children grow-up.

Design

Seven-year-old school children (53 boys and 57 girls) were recruited to measure their SSFR in mL/min. Paraffin-stimulated saliva was collected from each child at baseline and once annually, over six years. Forty-four boys and 46 girls remained in the cohort (dropout rate 18%). Cluster analysis was applied to evaluate the natural grouping of individuals according to their SSFR. Partition analysis was applied to calculate the SSFR cut-off value to predict a child's salivation trend.

Results

Cluster analysis revealed that as they grew-up these children consistently showed one of three different SSFR patterns. The cut-off values to predict a child's salivation trend were 1.76 mL/min for the high SSFR cluster, and 0.5 mL/min for the low SSFR cluster.

Conclusions

These findings indicate that a high or low SSFR is a constant individual trait in children.     

Efficacy and safety of Chinese patent medicines in the treatment of recurrent aphthous stomatitis: A systematic review

Background

Recurrent aphthous stomatitis (RAS) is the most common chronic oral mucosal condition of the oral cavity. Investigators in clinical trials have evaluated the effectiveness of Chinese patent medicines in the treatment of RAS. However, the results are conflicting rather than conclusive. To evaluate the efficacy and safety of Chinese patent medicines for the treatment of RAS, the authors conducted a systematic review.

GCF and serum myeloperoxidase and matrix metalloproteinase-13 levels in renal transplant patients

Aim

The rationale of this study was to address whether local or systemic changes reflect proteolytic (matrix metalloproteinase-13) or oxidative (myeloperoxidase) stress in renal transplant patients receiving cyclosporine-A (CsA) and having gingival overgrowth (GO), in patients receiving CsA therapy and having no GO and patients receiving tacrolimus therapy.

Material and methods

Gingival crevicular fluid (GCF) samples were collected from sites with (GO+) and without GO (GO−) in CsA patients having GO; GO− sites in CsA patients having no GO; sites from tacrolimus, gingivitis and healthy subjects. GCF and serum myeloperoxidase (MPO) and matrix metalloproteinase-13 (MMP-13) levels were determined by ELISA.

Results

GO+ sites in CsA patients having GO had elevated GCF MPO levels than those of CsA patients having no GO, tacrolimus and healthy subjects (p < 0.005), but comparable to those of gingivitis. GCF MPO levels were higher in GO+ compared to GO− sites in CsA patients having GO (p < 0.05). Patient groups had similar, but higher GCF MMP-13 levels than healthy group.

Conclusions

These results show that CsA and tacrolimus therapy have not a significant effect on GCF MPO and MMP-13 levels, and gingival inflammation seems to be the main reason for their elevations.     

Parasympathectomy induces morphological changes and alters gene-expression profiles in the rat submandibular gland

Objective

The chorda-lingual (CL) nerve carries parasympathetic fibers to the hilum of the sublingual and submandibular glands (SMGs) and evokes the secretion of saliva. The effect of cutting the CL nerve on the biological processes in SMGs was investigated by examining the gene-expression profiles in the SMGs after a surgical parasympathectomy.

Methods

At day 3 after the CL nerve cut, the changes in the SMGs at both the experimental cut and contralateral control sides were analysed by microarray and light microscopy. The expression levels of 6 selected genes were confirmed by real-time PCR, Western blot and immunofluorescence staining.

Results

The wet weight of the parasympathectomised SMGs decreased significantly compared to that of the contralateral side (p < 0.05). Histological analyses after the parasympathectomy showed a widened interacinar space as well as some atropic changes to the acini of the SMGs in the cut side. Microarray analysis revealed that twofold differential expression in mRNA expression in the parasympathectomized SMGs were detected in 88 genes (0.004%): 41 genes were overexpressed, 11 were underexpressed and 36 were unknown. Changes of the expression of 6 selected genes detected by Western blot and/or real-time PCR were consistent with the microarray data.

Conclusion

The important genes involved in biological processes for salivation were identified through a large-scale gene expression analysis.     

Regenerative endodontic treatment (revascularization) for necrotic immature permanent molars: a review and report of two cases with a new biomaterial

Introduction

Revascularization is a valuable treatment in immature necrotic teeth that allows the continuation of root development. In this article we describe successful revascularization treatment of 2 necrotic immature first mandibular molars.

Methods

The clinical and radiographic examinations showed extensive coronal caries, immature roots, and periapical radiolucencies in mandibular first molars of a 9-year-old boy and an 8-year-old girl. The exam findings suggested revascularization treatment in both cases, which was started with irrigation of the canals by using NaOCl 5.25% for 20 minutes, followed by 3 weeks of triple antibiotic (metronidazole, ciprofloxacin, and minocycline) paste dressing. Next, the antibiotic paste was removed, bleeding was induced in the canals, and calcium enriched mixture (CEM) cement was placed over blood clots.

Results

In radiographic and clinical follow-ups both cases were asymptomatic and functional, periapical radiolucencies were healed, and roots continued to develop.

Conclusions

Revascularization is a realistic treatment in immature necrotic molars. In addition, placing CEM cement as a new endodontic biomaterial over the blood clot formed inside the canals provided good seal and favorable outcomes.     

Evaluation of serum zinc levels in patients with recurrent aphthous stomatitis (RAS)

Background

Recurrent aphthous stomatitis (RAS) is an ulcerative disease of the oral mucosa without a clearly defined etiology. The aim of the study was to evaluate the serum zinc levels in patients with RAS in comparison to healthy controls and to validate the association between zinc levels and the course of RAS.

Methods

Seventy-five patients with RAS and 72 controls underwent full dental examination. Serum zinc levels were determined by flame atomic absorption spectroscopy (F AAS). The results were statistically analyzed with Kruskal-Wallis, Mann-Whitney, chi-square tests and the test of difference between the two rates of structure with p?<?0.05 as a significance level (Statistica 10, StatSoft®).

Results

No statistically significant differences were detected in serum zinc levels between RAS patients and healthy controls. The mean serum zinc concentration was found to be 84.2 μg/dL in RAS group and 83.9 μd/dL in controls, within the accepted norms. Zinc deficiency was observed in 10.7% patients from the RAS group and in 6.9% controls. No significant differences in serum zinc levels were found between patients when the course of the disease was considered.

Conclusions

Serum zinc concentrations did not differ significantly in RAS patients and in healthy controls and it did not influence the course of the disease. Therefore, zinc does not appear to be an important modifying factor in the development of RAS.

     

The interactions of epigallocatechin-3-gallate with human whole saliva and parotid saliva

Objective

The aim of the present study was to assess the null hypothesis that the astringency and loss of lubrication in the oral cavity are not related to the properties of the epigallocatechin-3-gallate (EGCG) adlayer, the affinity and the entropy-drive of EGCG binding to saliva.

Methods

The mass, thickness, and viscoelasticity of the EGCG adlayer and the temperature-dependence of EGCG adsorption onto saliva surfaces were determined by quartz crystal microbalance with dissipation (QCM-D). The affinities of EGCG to human whole saliva (WS) and to parotid saliva (PS) were carried out by QCM-D monitoring and fluorescence quenching.

Results

The stiffer and more compact EGCG adlayers were formed on saliva surfaces at various concentrations of EGCG. The affinity for EGCG binding to WS was higher than that to PS. The precipitation of EGCG/saliva was temperature-dependent. The driving force of EGCG binding to saliva is dominated by the hydrogen bond, the hydrophobic reaction, and the entropy-drive, which were confirmed by the FTIR spectra and the measurement of temperature-dependence, respectively.

Conclusion

The viscoelasticity of the EGCG adlayer, the affinity of EGCG to saliva, and the priority of EGCG binding to hydrophobic proteins on the mucosa may account for the oral astringency and loss of lubrication.     

Continued development of the root separated from the main root

Introduction

Endodontic infection or physical trauma of a developing tooth might lead to unusual situation for root development.

Methods

Two cases are presented. Both cases involved immature mandibular second premolars with infected pulps. In the first case, the tooth was treated by apexification, whereas revascularization procedures were performed in the second case. Interestingly, a separated root tip was observed with the main root at the initial presentation of case 2.

Results

At recall after apexification, a separate root tip was observed apically to the main root end, and root development continued in case 1. In the second case, the separate root displayed continuing root formation, but the main root did not gain root thickness or length.

Conclusions

These cases revealed that Hertwig’s epithelial root sheath and stem cells from the apical papilla can be separated from the main tooth structure by an external force or iatrogenic factors and thereafter produce a separate root tip.     

A new technique for nonsurgical retreatment of teeth with amalgam root end fillings: case series

Introduction

The objective of this article was to show an alternative clinical approach to retreating teeth having had prior combined nonsurgical and surgical endodontic treatment with retrograde amalgam fillings. Nonsurgical retreatment performed alone has historically presented numerous challenges for the clinician and an uncertain outcome for the patient. Surgical retreatment has the potential disadvantages of additional root shortening, bone loss, and scarring.

Methods

Four cases are presented with recalls up to 5.5 years.

Results

The procedure was shown to be predictable and successful in this series. Root length was preserved, and surgery was avoided.

Conclusions

Nonsurgical amalgam removal from the root end may provide a desirable alternative to the more common and complicated option of combined nonsurgical and surgical endodontic retreatment.     

Intraosseous lipoma in the periapical region of a maxillary third molar

Introduction

Images of oral lesions can look so exceptionally similar that a diagnosis hypothesis could be difficult. Lesions mimicking apical periodontitis must be considered when making a differential diagnosis. Intraosseous lipoma is a rare benign tumor of low incidence among all bone tumors, and therefore few cases have been reported in the literature.

Methods and Results

A case of intraosseous lipoma associated with the distobuccal root of tooth #1 in a 39-year-old woman is described. The dental general practitioner did not perceive anything of note in terms of the radiographic aspect, so consequently the periapical lesion went unnoticed. However, after tooth extraction, a different feature was noticed in the surgical specimen. The lesion associated to the roots of tooth #1 was surrounded by soft tissue forming a fibrous capsule (10 mm in diameter). A histopathologic examination showed an area of bone of lamellar aspect surrounding a central area of fat tissue diagnosed as intraosseous lipoma. This type of lesion is asymptomatic, and its etiology is unclear.

Conclusions

Intraosseous lipoma should be considered in the differential diagnosis of other jaw lesions. A histologic examination is mandatory for the diagnosis, because this lesion is characterized by bone of lamellar aspect surrounding a central area of fat tissue. The treatment chosen in this case was surgical excision, and the outcome was favorable.     

Mandibular first molar with six separate canals

Introduction

Many anatomical variations can occur within the mandibular first molar. Commonly, 3-4 canals are located, but as many as 6-7 canals have been reported.

Methods

This report describes a case of a mandibular first molar with 6 separate canals (3 mesial and 3 distal) that was instrumented with conventional hand and rotary files and obturated by using a hybrid warm vertical compaction technique.

Results

Recall examination as far as 3 years post-treatment found no sensitivity to percussion or palpation and recall radiographs after treatment show resolution of the previous apical periodontitis.

Conclusions

The existence of such teeth as these underlies the importance of looking for additional canals.     

Immunohistological characterization of newly formed tissues after regenerative procedure in immature dog teeth

Introduction

In a previous report, we showed that 2 types of mineralized tissues were formed in the canal spaces of dogs after tissue engineering treatments of immature teeth with apical periodontitis: (1) dentin- associated mineralized tissue (DAMT) and (2) bony islands (BIs). The objective of this study was to characterize these mineralized tissues.

Methods

The maturation and organization of collagen matrices in DAMT, BIs, and the interface between DAMT and the dentin wall were characterized using a histochemical method with picrosirius red staining under polarized light microscopy. In addition, the distribution of 2 noncollagenous proteins (ie, dentin sialoprotein and bone sialoprotein) in these tissues was investigated by immunohistochemical methods with specific antibodies.

Results

The results showed that DAMT is distinct from dentin, bone, or BIs. Although it resembled cementum to an extent showing similar immunoreactivity to the noncollagenous proteins, the organization and maturation of collagen matrix was significantly different from cementum. BIs resembled a bone matrix in terms of morphology, collagen organization, and immunoreactivity.

Conclusions

The results indicate that DAMT and BIs formed in the canal space are distinct from each other, one exhibiting a unique mineralized tissue and the other a bone-like tissue.     

Calcium hydroxide inactivates lipoteichoic acid from Enterococcus faecalis through deacylation of the lipid moiety

Introduction

Lipoteichoic acid (LTA) is a major virulence factor of Enterococcus faecalis that is closely associated with refractory apical periodontitis. Recently, we have shown that calcium hydroxide, a commonly used intracanal medicament, abrogated the ability of LTA to stimulate the production of tumor necrosis factor α in a murine macrophage line, RAW 264.7. Because calcium hydroxide could potentially modify the glycolipid moiety of LTA, we examined if calcium hydroxide inactivates LTA through deacylation of the LTA.

Methods

LTA was prepared from E. faecalis by organic solvent extraction followed by chromatography with the hydrophobic-interaction column and the ion-exchange column. RAW 264.7 cells were stimulated with intact LTA or calcium hydroxide-treated LTA for 24 hours, and the productions of nitric oxide (NO) and chemokines interferon-gamma-induced protein (IP-10) and macrophage inflammatory protein-1α (MIP-1α) were determined. The glycolipid structure of LTA was analyzed using matrix-assisted laser desorption ionization-time of flight mass spectrometry and thin layer chromatography (TLC).

Results

The production of NO, IP-10, and MIP-1α was augmented in LTA-stimulated cells, whereas no such effect was observed upon stimulation with calcium hydroxide-pretreated LTA. Mass spectrometry showed that intact glycolipids of LTA yielded distinct mass peaks at 930 to 1,070 mass over charge (m/z) units, corresponding to dihexosyl-diacylglycerol consisting of two acyl chains with chain lengths of C₁₆ to C₂₂ and with one or two unsaturated double bonds. However, those peaks were not observed in the mass spectra of the calcium hydroxide-treated LTA. Furthermore, free fatty acids released from the calcium hydroxide-treated LTA were detected using TLC.

Conclusion

We suggest that calcium hydroxide attenuates the inflammatory activity of E. faecalis LTA through deacylation of the LTA.