Changes In Gingival Tissues Research Articles

Bone Volume Assessment Around Immediate Dental Implant in the Esthetic Area with Immediate Tooth-Like Single Crown Provisionalization: A Laser and Computed Tomography 1-Year Retrospective Study.

To examine the remodeling process of both the soft and hard tissue components of the postextraction socket around immediately loaded dental implants after tooth extraction in maxillary esthetic areas. Subjects underwent immediate placement of single implants in postextraction sockets without bone grafting, and their immediate provisionalization with custom tooth-like interim crowns were fabricated using digital diagnostic impressions and a dental milling machine. Intraoperative and 1-year follow-up layered scans of the postextraction sockets after implantation were acquired using a 3D optical system. In the short term, subjects underwent computed tomographic scans. Digital impressions for gingival contours, originally stored as STL (standard tessellation language) files, were converted to DICOM (Digital Imaging and Communications in Medicine) files with the implant shoulder working as a referral point, which were then superimposed to 3D radiologic images. The observed volumetric and linear outcomes were measured using a program known as DentaScan. The width of the alveolar crest at the level of the implant shoulder and marginal bone levels were acquired. Nonparametric tests were applied with a level of significance set at P < .01. No failure was reported after a follow-up of 1 year. Little or no inflammation of the treated areas was registered, and there were practically no signs of suppuration. The areas showed a significant reduction in the overall volumes for both soft and bone tissue, with a P value < .0001 from the baseline (0.983 ± 0.172 cm3) to the 1-year survey (0.865 ± 0.156 cm3). If the soft and bone tissue changes were separately evaluated, a significant loss (with a P value < .0001) was registered for only the bone tissues (from 0.434 ± 0.075 to 0.355 ± 0.061 cm3). Moreover, changes in gingival tissue from baseline to the 1-year survey (-0.040 ± 0.067) appeared to be significantly different from the overall volume loss (-0.118 ± 0.083 cm3). A shrinkage in width (-0.5 ± 0.7 mm) was found from baseline (12.6 ± 0.6 mm) to the 1-year follow-up (12.1 ± 0.9 mm). Marginal bone levels were 0.97 ± 0.70 mm and 0.39 ± 0.78 mm, respectively, at the mesial and distal aspects of the implants. The present analysis suggested that immediately customized provisionalization was effective enough to prevent both volume loss and linear shrinkage at the layers of the treated areas. Moreover, the buccal aspects seemed to be the areas most affected by the loss of volume. The mean loss in width, which amounted to roughly 0.5 mm, appeared to be negligible when compared to the overall width measured before surgery.

Investigating the relationship between periodontitis and specific memory processes in the search for cognitive markers of Alzheimer’s disease risk

The spontaneous retrieval deficit (SRD) hypothesis argues that individuals in the preclinical stages of Alzheimer’s disease (AD) are particularly impaired in spontaneous retrieval, which manifests in reduced mind-wandering. Our main purpose was to provide novel evidence to support the SRD hypothesis by investigating, for the first time, the relationship between mind-wandering and periodontitis, the latter being the risk factor for AD. The second objective was to address the lack of deeper understanding of the relationship between oral health and specific cognitive abilities by investigating whether periodontitis would be primarily associated with memory. Sixty community-dwelling dementia-free older adults completed neuropsychological tests that focused on various cognitive abilities and a computerised task, during which mind-wandering was evaluated. Periodontal health was assessed subjectively, and through an oral examination by a qualified dentist that focused on visible periodontitis-related changes in gingival tissues and the number of periodontitis bacteria. In line with our predictions, objective and subjective symptoms of poorer periodontal health were associated with less mind-wandering, providing further support for the SRD hypothesis. Again in line with predictions, poorer periodontal health was associated with worse episodic memory, with no relationship between periodontitis and the measure targeting various cognitive abilities, from which memory was excluded.

Cytomorphometric and Clinical Changes in Gingival Tissue after Subgingival Tooth Preparation-A Pilot Study.

Tooth preparation for a metal-ceramic crown with a subgingival finish line can lead to inflammatory changes in the gingival tissue, often accompanied by cell damage. This study aimed to evaluate the clinical signs of inflammation and the cytomorphological status of the gingival tissue before and after tooth preparation. The research included a homogeneous group of 19 patients with an indication for upper canine preparation. Before and after treatment, the gingival and the gingival bleeding indexes were determined, gingival swabs were taken, and direct smears prepared on slides for cytomorphometric analysis. The values of the measured gingival indexes were statistically significantly higher (p < 0.001) after tooth preparation. They decreased over time, which indicated the reversibility of the resulting changes. Cytological examination showed no statistically significant difference between the values of nuclear area, perimeter, Feret diameter, Feret angle, integrated optical density, MinFeret, and roundness, before and after the treatment. Significantly higher values of circularity, integrated optical density, MinFeret (p < 0.05), as well as roundness (p < 0.001) were found after 72 h, compared to those taken 15 min after tooth crown preparation. This study is a pioneering attempt to show gingival changes during fixed prosthodontic treatment and may shed new light on pathogenetic events in prosthodontic patients.

Effect of orthodontic retraction force on thick and thin gingival biotypes in different grades of gingival recession and alveolar bone quality: A finite element analysis.

To evaluate the effect of orthodontic retraction force on thick and thin gingival biotypes of anterior teeth having grade I and II gingival recession with D1 and D2 alveolar bone densities by assessing the displacement of teeth and deformation in gingival tissue, along with evaluating the amount of equivalent stress on teeth and gingiva in finite element model. Based on cone-beam computed tomography datasets, eight models (LC01-LC08) of maxilla with appliance assembly were created. A retraction load of 150 gm was applied on each model during the finite element analysis (FEA), and then values of teeth displacement, gingival deformation, and von Mises stress were evaluated. All the models with D1 bone density (LC01-04) were showing gingival deformation, whereas models with D2 bone quality (LC05-08) give no significant outcome. The amount of von Mises stress for teeth and gingival tissue in each model was the same for both central and lateral incisors. All the models having D1 bone quality showed greater gingival deformation after applying retraction force, whereas in models with D2 bone density, deformation was not significant. Changes in gingival tissue are brought about by orthodontic treatment, which also helps to correct the periodontal defects; however, bone density plays a significant role in improving gingival recession.

Evaluation of the periodontal status of a patient diagnosed with Sheehan syndrome: A case report

Aim: Some immunological changes occurring in mothers during pregnancy increase their susceptibility to infections, including periodontal infections. Sheehan syndrome (SS) is a disease that occurs because of severe postpartum hemorrhage causing ischemic pituitary necrosis. The presence of multiple hormonal deficiencies leads to the impairment of bone microarchitecture, which can cause osteopenia and even osteoporosis. Osteoporosis and periodontitis are both chronic diseases characterized by bone loss. Moreover, recent studies have shown that there is a relationship between menopause, osteoporosis, alveolar bone resorption, and tooth loss. This case report aims to evaluate the oral and periodontal status of a patient with SS and to raise awareness about dental and periodontal problems that may occur in such patients.&#x0D; Methodology: A 63-year-old female patient diagnosed with SS in the endocrinology clinic was referred to the periodontology clinic with complaints of multiple tooth loss, mobility in her teeth, and gingival bleeding. In the clinical and radiographic examination of the patient, it was determined that all teeth had horizontal bone resorption; moreover, there was mobility in the mandibular anterior teeth and hemorrhage in the gums. When the patient’s laboratory results were examined, it was seen that the basal plasma levels of free triiodothyronine (T3) and thyroxine (T4), growth hormone (GH), prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH), progesterone, and total testosterone values were significantly lower, and the anterior pituitary elevation was significantly decreased in pituitary magnetic resonance (MR) imaging.&#x0D; Conclusion: The periodontium is the target tissue of sex and other hormones. Hormonal changes may affect the inflammatory–immune tissue responses of periodontal tissues. Many studies have shown that thyroid and sex hormones affect oral and especially periodontal tissues. The degradation of hormonal hemostasis may induce a series of pathological events in the oral environment, resulting in inflammatory changes in gingival tissues, periodontal attachment losses, and destruction of the alveolar bone. Systemic diseases that affect hormonal conditions, such as SS, must be considered in the evaluation of oral health. Medical physicians should refer their patients to the dentist for consultation when evaluating patients’ hormonal status and planning their treatment.&#x0D; &#x0D; How to cite this article: Şen SC, Saygun NI, Or Koca A, Özcan E. Evaluation of the periodontal status of a patient diagnosed with Sheehan syndrome: A case report. Int Dent Res 2021;11(Suppl.1):308-11. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.46&#x0D; &#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.&#x0D;

Evaluation of gingival tissue samples for predicting the time of death using histological and biochemical tests

Thanatochemistry also known as chemistry of death and is used to determine post mortem interval (PMI). It is arguably one of the critical steps in forensic investigation. Recent addition of analyzing biochemical changes along with the traditional methods have gained importance, as they help us to record very early changes in the tissue specimens. In this view, our study aimed to correlate both histological changes and enzymatic changes in gingival tissue samples at intervals of immediate, 1 h, 5 h, 24 h and 48 h after death. Histologic changes noted were loss of epithelial architecture, chromatin clumping, nuclear vacuolation, karryopyknosis, eosinophilia and wide intercellular junctions. Two enzymes which differentiate between the autolytic phase (acid phosphatase) and putrefactive phase (ammonia) of decomposition were evaluated using UV spectrometer. Results in our study demonstrated there were variations as in gradual increase in ammonia levels (1.13±0.24–26.6±2.09) and gradual decrease in acid phosphatase levels (5.61±0.67–1.25±0.53) at different time intervals till 48 h. The cellular changes in gingival tissue could also be related to time. The result of our study helps us to identify potential of enzymatic changes which when correlated with histological reports helps us to predict the time of death accurately. Replicating this experiment in various known taphonomic conditions and other enzymes could highlight the usefulness of gingival tissue samples in determining time of death.

Inflammatory Enlargement of the Gingiva: A Case Report

Background: Gingival enlargement is one of the frequent features of gingival diseases. Inflammationof the gingival tissues can be induced by diverse method. All changes in gingival tissues express withsome degree of inflammation. In some cases, where gingival enlargement could be the primary sign ofpotentially lethal systemic diseases, a correct diagnosis of these enlargements could prove life saving forthe patient or at least initiate early treatment and improve the quality of life. Pertinent management dependson precisely diagnosing the origin of enlargement. The aim of publishing this case report is to present theclinical, histopathological features and treatment of inflammatory gingival enlargement which disturbed theaesthetics and masticatory function of the patient.Method: A 20 year old female patient reported with a chief complaint of swelling in the gums of teeth inlower front region. The enlargement was soft and friable and bleeding spontaneously making it difficult forthe patient to maintain adequate personal oral hygiene. Surgical therapy was carried out to provide a goodaesthetic outcome.Conclusion: No recurrence was reported. Gingival overgrowth is unaesthetic, and may interfere inmastication and speech; hence a thorough understanding of the pathogenesis is essential for management.

The Carcinogenic Potential of Cadmium in Gingival Epithelium of Rats (Histological and Immunohistochemical Study)

Cadmium is a toxic, heavy industrial metal that causes serious environmental health hazards. Cadmium containing compounds have been classified as known human carcinogens and epidemiological data show causal associations to different types of cancers. This study designed to assess the carcinogenic effects of Cadmium on the gingival tissue of rats. Material and methods; Sixteen male albino Rats (age: 8 to 10 weeks and about 150 to 180 g body weight) from Animal Center of Faculty of Medicine, Mansoura University. The animals were divided into two equal groups, group I (control) and group II (cadmium chloride) rats were given 2 ml dose of a solution containing 10 mg/kg body weight of monohydrated cadmium chloride orally by gavage needle for 24 days. By the end of experiments, gingival epithelium around the teeth were carefully dissected, processed and stained using Haematoxyline & Eosin and immunohistochemical evaluation by iNOS. Statistical analysis was done to observe the statistical significant differences between the Cd group and control group in relation to dysplastic changes and iNOS immunoreaction. Results: the gingival tissue of Cd group revealed several dysplastic changes as, drop shape rete pegs, loss of polarity of basal cells, nuclear hyperchromatism, pleomorphism and increased mitotic pattern. a statistical significant difference regarding iNOS immunoreaction was found between control group and Cd group. conclusion to this study Cadmium chloride at low concentration and longtime of exposure can cause dysplastic changes in gingival tissue of rats.

Facial Gingival Changes With and Without Socket Gap Grafting Following Single Maxillary Anterior Immediate Tooth Replacement: One-Year Results.

This 1-year prospective study evaluated horizontal and vertical facial gingival tissue changes after immediate implant placement and provisionalization (IIPP) with and without bone graft in the implant-socket gap (ISG). During IIPP, 10 patients received bone graft material in the ISG (G group), while the other 10 patients did not (NG group). The implants were evaluated for implant stability quotient (ISQ), modified plaque index (mPI), modified bleeding index (mBI), marginal bone level (MBL), facial gingival level (FGL), and facial gingival profile (FGP) changes. The mean ISQ value at 9-month follow-up was statistically significantly greater than on the day of implant surgery (P < .05). The mPI and mBI scores demonstrated that patients were able to maintain a good level of hygiene. There were no statistically significant differences in the mean MBL changes between the G and NG groups (P > .05). There were statistically significant differences in FGL changes between the G (-0.77 mm) and NG (-1.35 mm) groups (P = .035). There were no statistically significant differences in FGP changes between the G and NG groups (P > .05). However, statistically significant differences were noted in FGP change between the 3-12 and 0-12 month intervals in both groups (P < .05). Within the limitations of this study, although no significant differences were noted in FGP changes between groups, G group experienced significantly less FGL changes than NG group. Bone graft material placement into ISG seems to be advantageous for tissue preservation during IIPP. However, future long-term studies, with larger sample size, are needed to validate the efficacy of such procedure.

Probiotic Lactobacillus rhamnosus GG prevents alveolar bone loss in a mouse model of experimental periodontitis.

This study investigated the role of Lactobacillus rhamnosus GG (LGG) on bone loss and local and systemic inflammation in an in vivo mouse model of experimental periodontitis (PD). Experimental PD was induced in mice by oral inoculation with Porphyromonas gingivalis and Fusobacterium nucleatum over a period of 44days. The probiotic LGG was administered via oral inoculation or oral gavage prior to, and during disease induction. The antimicrobial activity of LGG on the inoculum was also tested. Alveolar bone levels and gingival tissue changes were assessed using in vivo microcomputed tomography and histological analysis. Serum levels of mouse homologues for IL-8 were measured using multiplex assays. Pre-treatment with probiotics either via oral gavage or via oral inoculation significantly reduced bone loss (p<.0001) and gingival inflammation (p<.0001) when compared with PD group. Oral gavage treatment group had significantly less tartrate-resistant acid phosphatase positive cells (p<.02) then PD group. LGG showed no antimicrobial activity against P.gingivalis and F.nucleatum. Lactobacillus rhamnosus GG effectively suppresses bone loss in a mouse model of induced PD irrespective of the mode of administration.

Effect of Supragingival Irrigation with Aerosolized 0.5% Hydrogen Peroxide on Clinical Periodontal Parameters, Markers of Systemic Inflammation, and Morphology of Gingival Tissues in Patients with Periodontitis.

BackgroundVarious studies have shown that non-surgical periodontal treatment is correlated with reduction in clinical parameters and plasma levels of inflammatory markers. The aim of this study was to evaluate the effect of long-term weekly supragingival irrigations with aerosolized 0.5% hydrogen peroxide as maintenance therapy followed by non-surgical periodontal treatment on clinical parameters, plasma levels of inflammatory markers, and morphological changes in gingival tissues of patients with periodontitis.Material/MethodsIn total, 43 patients with chronic periodontitis were randomly allocated to long-term maintenance therapy. The patients’ periodontal status was assessed using clinical parameters of approximal plaque index, modified gingival index, bleeding index, pocket probing depth, and plasma levels of inflammatory markers (high-sensitivity C-reactive protein and white blood cell count) at baseline and after 1, 2, and 3 years. The morphological status of gingival tissues (immediately after supragingival irrigation) was assessed microscopically.ResultsComplete data were obtained on 34 patients. A highly statistically significant and consistent reduction was observed in all long-term clinical parameters and plasma levels of inflammatory markers. Morphological data showed abundant spherical bubbles in gingival tissues.Conclusions1. The present study showed that non-surgical periodontal treatment with long-term weekly supragingival irrigations with aerosolized 0.5% hydrogen peroxide improved clinical periodontal status and plasma levels of inflammatory markers and may be a promising method in periodontology. 2. We found that supragingival irrigation with aerosolized 0.5% hydrogen peroxide created large numbers of spherical bubbles in gingival tissues.

Bone biology‐related gingival transcriptome in ageing and periodontitis in non‐human primates

Cellular and molecular immunoinflammatory changes in gingival tissues drive alveolar bone loss in periodontitis. Since ageing is a risk factor for periodontitis, we sought to identify age-related gingival transcriptome changes associated with bone metabolism in both healthy and in naturally occurring periodontitis. Adult (12-16years) and aged (18-23years) non-human primates (M. mulatta) (n=24) were grouped into healthy and periodontitis. Gingival tissue samples were obtained and subjected to microarray analysis using the Gene Chip Macaque Genome Array. Gene expression profiles involved in osteoclast/osteoblast proliferation, adhesion and function were evaluated and compared across and between the age groups. QPCR was also performed on selected genes to validate microarray data. Healthy aged tissues showed a gene profile expression that suggest enhancement of osteoclastic adhesion, proliferation/survival and function (SPP1, TLR4, MMP8 and TFEC) and impaired osteoblastic activity (SMEK3P and SMAD5). The gingival transcriptome in both adult and aged animals with naturally occurring periodontitis (FOS, IL6, TLR4, MMP9, MMP10 and SPP1 genes) was consistent with a local inflammatory response driving towards bone/connective tissue destruction. A pro-osteoclastogenic gingival transcriptome is associated with periodontitis irrespective of age; however; a greater bone-destructive molecular environment is associated with ageing in healthy tissues.

Assessment of histological changes in antemortem gingival tissues fixed at various time intervals: A method of estimation of postmortem interval

Introduction:Conventional methods to estimate the time of death are adequate, but a histological method is yet unavailable to assess postmortem interval (PMI). The autolytic changes that occur in an unfixed antemortem gingival tissue which reflects histologically at an early stage are similar to changes that occur in postmortem tissue. These histological changes can be used and applied in a postmortem tissue as a method to assess PMI.Aims:The aim of the study is to assess the histological changes in a gingival tissue left unfixed for various time intervals and to correlate the findings with duration.Materials and Methods:Sixty gingival tissues obtained from patients following therapeutic extractions, impactions, gingivectomy and crown lengthening procedures were used. Each tissue obtained was divided into two pieces and labeled as “A”, the control group and “ B” the study group. Tissues labeled “A” were fixed in 10% formalin immediately and tissues labeled“B” were placed in closed containers and fixed after 15, 30, 45 min, 1, 2, and 4 h time interval. Of the sixty tissues in the study group “ B”, ten tissues were used for each time interval under investigation. All the fixed tissues were processed, stained, assessed, and analyzed statistically using Pearson correlation and regression analysis.Results:Histological changes appear at 15 min in an unfixed antemortem tissue. At 2 h interval, all layers with few cells in basal cell layer are involved. At 4 h interval, loss of stratification and complete homogenization of cells in the superficial layers with prominent changes in basal layer is evident. There was a positive correlation (<1.0) between the time interval and the appearance of the histological changes.Conclusion:Histological changes such as complete homogenization of cells in superficial layers and loss of epithelial architecture at 4 h in unfixed antemortem tissue may be used as a criterion to estimate PMI, after further studies on postmortem tissues.

Clinical and morphological assessment of low frequency ultrasound use in delayed eruption of teeth

Aim. Development of a new method stimulating eruption of impacted teeth, reducing side effects and the term of orthodontic treatment.&#x0D; Methods. Considering the high numbers of patients who sought medical aid with delayed eruption of teeth, rational method of low-frequency ultrasound was used for stimulating eruption of impacted teeth. The stimulation process was performed by «SIAZ-EGS Med-Stomo» device, with the oscillation frequency of 26.5 kHz, intensity of 1 W/cm, amplitude of 40-60 μm, a wavelength 0,012 m, developed in Azerbaijan. Clinical and morphological methods, including examination of gingival tissue biopsies from the area where low-frequency ultrasound was applied, were used. After clinical and radiographic examination and identifying the impacted tooth with a favorable location on dental panoramic radiography, if there was a space in the tooth row, the area of the tooth projection at the gum was directly affected by low-frequency ultrasound daily or every other day for 5-10 seconds. An average of 1-5 procedures up to the tooth eruption was performed.&#x0D; Results. Microscopy of epithelial cover and stroma proved the absence of inflammation, thickening of outermost layer on the gum surface. Cells of the intermediate layer revealed the intact nucleus, loosening with linear swelling and cell dissociation. Cellular and tissue changes in gingival tissue seen after the treatment with low-frequency ultrasound may indicate the boosting of the impacted teeth eruption due to the syndrome of molecular contusion, improving the microcirculation and loosening the gum tissues.&#x0D; Conclusion. The results of comprehensive orthodontic treatment using low-frequency ultrasound ito stimulate the eruption of impacted teeth may be recommended for practical use.

Long-term effects of nifedipine on human gingival epithelium: a histopathological and immunohistochemical study

The chronic usage of nifedipine is associated with the appearance of gingival overgrowth (GO). The frequency of GO associated with chronic nifedipine therapy remains controversial and the possible subclinical effects of this drug on the gingival epithelium should be investigated. We investigated the epithelial proliferation index and apoptosis rate, and their association with epithelial enlargement. Proliferation (Ki67 and Cyclin B1) and apoptosis (BCL2, Bax and p53) markers were identified by immunohistochemistry in twenty-one samples of gingival tissue from patients undergoing chronic treatment with nifedipine and in eleven samples of gingival tissue from healthy patients who did not use drugs associated with GO (control). Our results show that the epithelial tissue of nifedipine users has considerably longer rete pegs compared to control (P = 0.01). However, the density of Ki67(+) and Cyclin B1(+) cells was similar in both groups. Regarding apoptosis, we found more BCL2(+) cells in the nifedipine group when compared to controls (P = 0.12). An increase in Bax(+) cells in the nifedipine group compared to control (P = 0.003) was also seen, and slightly lower levels of p53(+) expression were observed (P = 0.51). Our results suggest that the chronic use of nifedipine is not associated with subclinical changes in gingival tissue.

Analysis of changes in gingival contour from three‐dimensional co‐ordinate data in subjects with drug‐induced gingival overgrowth

This aim of this study was to develop and assess a technique that could be used to assess accurately the gingival volume changes seen in drug-induced gingival overgrowth by the analysis of data obtained from an entire gingival surface by means of three-dimensional imaging. Stone dental models of patients before and after gingivectomy procedures were digitized with a laser scanner and then regenerated as computer models constructed from the acquired three-dimensional co-ordinate data. A comparison of superposed "before" and "after" surfaces was undertaken to assess and accurately quantify changes in gingival contour. The mean vertical tissue reduction varied from 1.58 to 2.56 mm in the four study subjects and individual differences are shown. The maximum thickness of removed buccal gingival overgrowth was found to range between 1.20 and 3.40 mm. The volume of tissue removed from each inter-dental papilla ranged from 4.2 to 46.1 mm3 and the mean volume of the papilla removed from each subject+/-SD values was 24.8+/-13.1 mm3. This method will measure changes in gingival tissues to within 60 microm in one plane, making it ideal for the assessment of longitudinal changes in gingival contour as seen in the development of gingival overgrowth, its recurrence after surgery or the changes in volume brought about by surgery.

Long-term effect of mandibular midline distraction osteogenesis on the status of the temporomandibular joint, teeth, periodontal structures, and neurosensory function

Purpose: This study retrospectively evaluated the long-term effects of transverse symphyseal distraction osteogenesis (DO) on the temporomandibular joint (TMJ) symptoms, periodontal health, tooth vitality, and nerve injury after surgery. Patients and Methods: Twenty-three patients were treated with symphyseal DO during a 4-year period. Fifteen patients were available for follow-up from 7 to 45 months postoperatively (ave, 24.5 months). The patients were clinically evaluated for TMJ symptoms, periodontal pocket formation, tooth vitality and mobility, crestal bone loss, and attached gingival tissue changes. Radiographs of the mandibular anterior teeth were used to evaluate for periodontal bone loss, periapical lesions, or widening of the periodontal ligament (PDL). Results: Preoperatively, 47% of the patients had TMJ symptoms. No patient had symptom worsening or developed new symptoms postoperatively. Five patients' TMJ symptoms improved, and 3 experienced complete resolution of symptoms. No periodontal bone loss or soft tissue recession were evident. Tooth vitality was maintained in 13 patients. Two patients developed Class II mobility of 1 mandibular central incisor, 1 patient had tooth pain and a widened PDL adjacent to the osteotomy/corticotomy site, and 1 patient experienced mental nerve paresthesia. Conclusions: DO can be used to treat transverse discrepancies of the mandible with limited morbidity.

Periodontal variables affecting nifedipine sequestration in gingival crevicular fluid

We previously demonstrated the sequestration of nifedipine in gingival crevicular fluid (GCF), especially in patients exhibiting significant gingival overgrowth. The aim of the present study is to determine the role of site specific periodontal factors in this phenomenon. 10 adult patients exhibiting nifedipine induced gingival overgrowth were studied. In each patient GCF was harvested from two sites that demonstrated inflammation and increased probing depth as well as from two clinically healthy sites. The concentration of nifedipine was determined using gas chromatography. Drug concentrations were significantly increased in the presence of inflammation (p = 0.004) and plaque (p = 0.029) whilst increased probing depths and gingival overgrowth were not significantly related to drug sequestration. We can conclude that inflammatory changes in gingival tissues appear to be a significant determinant for the sequestration of nifedipine in the GCF.

カラーレスポーセレン冠の歯肉組織におよぼす影響

This study has revealed the effects of collarless metal-ceramic crowns on the dog gingival tissues at one and three months after setting, and compared the effects with those of metal-ceramic crowns by means of light-and scanning electron microscopy. In addition, the morphology of the marginal surface of these two types of crowns was also examined before setting. The results obtained were summarized as follows : 1. It seemed to be necessary to use the correct powder of margin (C.P.M.) for getting a good adapted margin of collarless metal-ceramic crowns made by the non-matrix method. 2. The average thickness of cement layers was 66.2μm in metal-ceramic crowns and 73.2μm in collarless metal-ceramic crowns. 3. Similar inflammatory changes in gingival tissues were observed in both cases of these two crown types by light- and scanning electron microscopy, even when the brushing treatment was performed during experimental periods. 4. Plaque observed in the area of the crown margin had a tendency to accumulate in the boundary between metal collar and porcelain in metal-ceramic crowns, and in the rounded marginal surface in collarless metal-ceramic crowns. 5. When margins of these two types of crowns were observed scanning electron microscopically before setting, a number of pits were found on the surface closely associated with metal collar in case of metal-ceramic crowns. In collarless metal-ceramic crowns, on the other hand, the surface of C.P.M. showed rough appearances. 6. Roughness of C.P.M. surface could be reformed smoothly by reglazing after scraping its superficial layer with sandpaper- or white points.

Long-term gingival conditions after orthodontic closure of extraction sites. Histological and histochemical studies.

To evaluate the long-term gingival tissue changes following orthodontic space closure, biopsies comprising gingival papillae were taken in nine patients from maxillary premolar extraction sites from 0 to 15 months after closure by edgewise appliances. Histomorphological examination, a chemical component histochemical investigation and an enzyme histochemical analysis were performed. Clinically the initial moderate gingival hyperplasia disappeared within a few months but an induced invagination remained and in these areas deep proliferations of the oral epithelium were found histologically. The surrounding connective tissue sometimes exhibited loss of collagen. These changes indicate permanent damage to the gingival tissues. The same histological and histochemical picture was obtained irrespective of time after closure of the extraction site. The papillae were excised a second time to evaluate the results of the earlier papillectomy. The second biopsy showed almost unchanged hyperplastic epithelial reactions and invaginations but development of a more ‘mature’ connective tissue in the papillary area evidently more resistant to inflammation. Removal of gingival papillae in closure sites seems to favour restitution of a more normal connective tissue.