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At least 127 records · Page 7Linked to original sources

Resorbable barrier and envelope flap surgery in the treatment of human gingival recession defects. Case reports.

The present case report evaluates the treatment outcome following mucogingival surgery combined with a bioresorbable barrier in gingival recession defects in humans. A total of 11 buccal, Miller Class I or II, gingival recession defects in 6 patients were consecutively treated. The exposed root surface was ultrasonically scaled and conditioned with a tetracycline HCl solution (10 mg/ml) for 4 min. A buccal full/split thickness envelope flap was then elevated, and a bioresorbable matrix barrier was positioned to completely cover the exposed root surface and surrounding bone margins. A flap was then positioned at or slightly coronal to its original position. In all cases, a variable amount of membrane was intentionally left uncovered on the exposed root surface. Clinical recordings, assessed presurgery and at 6 months postsurgery, included defects-specific plaque and gingival scores, recession depth (RD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KT). Immediately postsurgery, and at weeks 1, 2, 4, 6 and 8 postsurgery, the location of gingival margin or granulation tissue covering the previously exposed root surface was recorded, as well as the extent of barrier exposure. Statistical analysis showed that RD decreased from 2.3+/-0.2 mm presurgery to 0.8+/-0.5 mm at 6 months postsurgery (p=0.001), representing a mean root coverage of 65% (range: 40-100%). CAL gain paralleled RD reduction (1.5+/-0.5 mm; p=0.0009), while KT showed a slight increase (0.3+/-0.6 mm) at 6 months postsurgery. Results indicate that clinical improvement of gingival recession defects may be achieved by means of a barrier-supported envelope technique. The bioresorbable matrix barrier represented an effective scaffold to support the reconstruction of the mucogingival unit.

Adult↗

Influence of tobacco smoking on periodontal bone height. Long-term observations and a hypothesis.

AIM: The aim of the investigation was to estimate the magnitude of the long-term influence of chronic smoking on the periodontal bone height. METHODS: The study population included 19 continuous smokers, 28 former smokers and 44 non-smokers in the age range 20-60 years at baseline. The participants were examined at two points in time with an interval of 10 years. The height of the periodontal bone was determined from bite-wing radiographs of the first and second premolars of the maxilla and the mandible and measured from the cemento-enamel junction (CEJ) to the periodontal bone crest (PBC) mesially and distally to the preselected teeth. RESULTS: The mean (SD) CEJ-PBC distance at baseline was 1.82 (1.01) mm for smokers, 1.65 (0.81) mm for former smokers, and 1.16 (0.59) mm for non-smokers (p=0.016). The mean (SD) 10-year bone height reduction was 0.74 (0.59) mm for smokers as against 0.26 (0.31) mm for former smokers and 0.27 (0.29) mm for non-smokers. Controlling for age and baseline bone height level, the magnitude of the reduction was significantly dependent of smoking (p=0.000). The widening gap between smokers and non-smokers over time suggested that the bone height reduction of smokers took place at an accelerated rate. CONCLUSION: On the basis of the observations it is hypothesized that smoking induces an acceleration of the periodontal bone height reduction rate and that smoking cessation results in a return towards non-smoker rate.

Adult↗

Classification, reproducibility and prevalence of root proximity in periodontal patients.

AIM: The primary aim of this study is to define and classify root proximity. The secondary aim is to examine the reproducibility of the measurement tools, to study the prevalence per inter-dental area and to examine whether the distance from the cemento-enamel junction (CEJ) to the bone crest (BC) differs between sites with root proximity and their contra-lateral sites without root proximity. MATERIAL AND METHODS: In order to indicate the location of root proximity, a modification of the Shei ruler was developed, dividing the roots into three equal parts. A radiographic template was used to measure the distance between the roots, in this way determining the severity of the root proximity. The reproducibility of the measurement tool was tested, the prevalence was calculated and the distances CEJ-BC for root proximity sites and contra-lateral sites were recorded. RESULTS: A two-digit classification was obtained dividing the root into three locations [apical (A), between (B) and coronal (C)], with each location having the possibility of three different severities of root proximity. The described modification of the Shei ruler and the measurement tool for the severities can be considered as reproducible measurement tools. Root proximity was most prevalent in maxillary molars and between central and lateral incisors in the maxilla and mandible. There was no difference in CEJ-BC distance between the root proximity sites and their contra-lateral sites. CONCLUSION: We can conclude that a two-digit classification for root proximity was established. Root proximity in untreated periodontal patients has no influence on the distance CEJ-BC. However, the location of root proximity becomes important from the moment that periodontal disease has been established at that site. The severity of root proximity is important for choosing treatment options. There is a striking similarity between bone loss patterns and tooth loss and the location of inter-dental spaces where root proximity is most prevalent.

Adolescent↗

Root proximity as a risk marker for periodontal disease: a case-control study.

AIM: The aim of this study is first, to examine the prevalence, symmetry and spread of root proximity using the measurement tools and classification as described in part I of the study, and second to examine whether root proximity is a risk marker for periodontal disease. MATERIAL AND METHODS: The radiographs of 227 patients were examined. The study consisted of a study group of 197 patients with advanced periodontal disease with at least one site with bone loss more than one third of the root length and 30 controls without periodontal disease. Every inter-proximal space was assessed on the full-mouth radiographs and a score was assigned according to severity and location. Consequently prevalence of severity and location, symmetry, spread and an odds ratio and relative risk for periodontal disease was calculated. RESULTS: Root proximity is a symmetrical and localized but widespread phenomenon in periodontal patients and to lesser extend in the non-periodontal control group. In periodontal patients root proximity was most often encountered in the coronal and intervening part whereas subjects without periodontal disease had more root proximity in the apical and intervening part where it is less critical. Subjects with bilateral root proximity had a 3.6 times higher chance to have periodontitis. CONCLUSION: Root proximity must be taken into consideration as a risk marker for periodontal disease.

Adolescent↗

Bone level around endodontically treated teeth in periodontitis patients.

OBJECTIVES: This retrospective study compared the marginal bone level of teeth with root canal fillings with contra-lateral teeth without. METHODS: Of 286 consecutive patients (> or =35 years), referred to practice for periodontology in the Netherlands, 67 full sets of radiographs contained > or =1 endodontically treated tooth and its contra-lateral tooth without root canal treatment. Bone level at the mesial and distal of these teeth was scored from the CEJ. In multi-rooted teeth, the presence of interradicular radiolucency was assessed. The presence of posts, and periapical radiolucencies was assessed. Analysis for differences between treated teeth and contra-laterals was controlled for tooth surface, presence of a post and tooth type. RESULTS: The mean distance from the root filling to the apex was 2.6 mm. Periapical radiolucencies were found in 14%. The mean bone level was at 4.3 mm for endodontically treated teeth and at 3.7 mm for contra-laterals. Significantly more bone loss (0.6 mm) was found at the endodontically treated teeth. No difference was found between mesial and distal, teeth without and with posts and different tooth types. The presence of interradicular radiolucency was more frequent in endodontically treated teeth (OR 2.1, p(McNemar test)=0.039). CONCLUSION: In periodontitis patients, teeth with endodontic treatment had more bone loss as compared with untreated contralaterals.

Adult↗

Case-control study of non-carious cervical lesions.

An exploratory case-control study of non-carious cervical lesions was undertaken to examine the effects of a variety of risk factors. Candidate exposure variables were related to erosion, abrasion, and tooth flexure, the three principal putative causal mechanisms for cervical lesions. Because previous studies have tended to focus on specific causal mechanisms, evidence for a multifactorial etiology is inconclusive. Data describing exposure factors were obtained through clinical examination, dietary and behavioral questionnaires, and analysis of study casts from 264 subjects (137 cases, 127 control). Salivary data were also obtained for a subset of these subjects. Patient and tooth-level logistic regression models were constructed for the full subject group, and the subset with salivary data. For the two patient-level models, only exposures related to brushing entered. For tooth-level models, multiple exposures representing all three causal mechanisms were included in both models. The results suggest that non-carious cervical lesions do have a multifactorial etiology, and that multiple causal mechanisms may operate in the initiation and progression of individual lesions.

Adult↗

Assessment of enamel hypoplasia in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).

The features of enamel hypoplasia in a small group of patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are described. Using a recently developed method, the authors evaluated quantitatively the amount of defect in each tooth by measuring the width of the hypoplastic lesions and dividing the value by the crown height. They then assessed the degree of damage in each tooth type (from central incisors to second premolars) and patient. Canines were the most severely affected among maxillary and mandibular teeth, but all tooth types were involved. Analysing both the differences between patients and their age at the beginning of the defect, the authors observe that hypoparathyroidism is not responsible for the onset of enamel hypoplasia in APECED, although it may contribute to the damage.

Adult↗

Dental erosion. Definition, classification and links.

An overview of tooth wear, i.e. of non-carious destructive processes affecting the teeth including abrasion, demastication, attrition, abfraction, resorption and erosion is presented. The nomenclature and classification of dental erosion commonly used in the dental literature are summarized. They are based on etiology (extrinsic, intrinsic, idiopathic), on clinical severity (Classes I to III), on pathogenetic activity (manifest, latent) or on localization (perimolysis). Interactions between erosion and abrasion, demastication, attrition, and abfraction as well as caries and low salivary flow rate are highlighted.

Acids↗

Mechanical properties across hypomineralized/hypoplastic enamel of first permanent molar teeth.

The aims of the present study were to investigate the mechanical properties of first permanent molars affected with enamel hypomineralization or hypoplasia, and to describe the appearance of these lesions under scanning electron microscopy. Eight first permanent molar test teeth and two unaffected premolars (controls) were enclosed in resin, then sectioned axially and polished. The hardness and modulus of elasticity was determined from a single array of indentations made parallel to the amelo-dentinal junction using an Ultra-Micro-Indentation system. The teeth were then examined using the scanning electron microscope. The mechanical properties of the test teeth in the unaffected cervical region (hardness and modulus range, 2.03-4.99 GPa and 50.39-96.87 GPa, respectively) were similar to those of the control enamel (hardness and modulus range, 2.71-4.15 GPa and 62.06-95.77 GPa, respectively). Between the unaffected cervical enamel and the hypomineralized region there was a transitional area of 500-600 microm where the mechanical properties in the experimental teeth decreased linearly. The mechanical properties of the hypomineralized region of each experimental tooth were significantly lower than those of the control or cervical regions (hardness and modulus range, 0.07-1.74 GPa and 3.26-40.96 GPa, respectively). The scanning electron microscopy views revealed disorganized enamel with poorly demarcated prism boundaries in the affected regions. In conclusion, the hardness and modulus of elasticity of hypomineralized enamel in first permanent molars is significantly less than in unaffected areas of the same tooth. The reason for this is unclear but may be related to the lack of organization of the enamel crystals.

Crystallography↗

Three-year clinical effectiveness of a two-step self-etch adhesive in cervical lesions.

A 3-yr randomized, controlled prospective study evaluated the clinical effectiveness of a mild two-step self-etch adhesive, Clearfil SE, in Class-V non-carious lesions. The hypothesis tested was that prior selective etching of enamel with phosphoric acid does not affect the 3-yr clinical performance of this adhesive. A total of 100 lesions in 29 patients were randomly restored in one or two pairs, according to two experimental protocols: (i) application of Clearfil SE according to the instructions of the manufacturer (C-SE non-etch); and (ii) similar application of Clearfil SE with prior etching of enamel cavity margins with phosphoric acid (C-SE etch). Clearfil AP-X was used as a restorative material. At 3 yr, 90% of the restorations were examined for retention, marginal integrity, marginal discoloration, caries recurrence, postoperative sensitivity, and preservation of tooth vitality. An excellent retention rate (100%) was noted after 3 yr of clinical functioning. Only one restoration of the C-SE etch group was clinically unacceptable owing to the presence of a severe cervical marginal defect. A pairwise comparison between both groups showed a significant difference only in the number of small marginal defects at the enamel side, which was higher in the C-SE non-etch group. These incisal defects were small and clinically irrelevant. Superficial marginal discoloration increased slightly in the C-SE non-etch group and was related to the higher frequency of small incisal marginal defects. In this latter group, localized marginal discoloration was observed significantly more in smokers. In conclusion, the clinical performance of the mild two-step self-etch adhesive, Clearfil SE, remained excellent after 3 yr of clinical functioning. Additional etching of the enamel cavity margins was not critical for its clinical performance.

Acid Etching, Dental↗

New cementum formation induced by cyclosporin A: a histological, ultrastructural and histomorphometric study in the rat.

Cyclosporin A (CsA), a widely used immunosuppressive agent, is known to induce gingival overgrowth; 30 mg/kg/d of CsA were administrated orally in young and adult male Sprague-Dawley rats. The same number of rats received oil-based vehicle solution. After 4, 9, 14 and 19 wk of CsA or vehicle administration 3 control and 3 experimental rats were anaesthetized and tissues fixed by an intracardiac perfusion of fixative solution. Upper and lower jaws were dissected, demineralized and processed for Epon inclusion. Histological examination revealed the presence of large amounts of new cementum (NC) covering extensive areas of the acellular extrinsic fibre cementum (AEFC) in all the root surfaces. NC was particularly abundant at the cervical third of the roots facing the gingival connective tissue, where it occurred as layers, spurs or in both configurations. NC was characterized by its irregular outline, globular body content and infrequent presence of incremental lines. Histomorphometric evaluation by semi-automatic image analysis indicated that the volume and the external surface of NC spurs were 2.86-6.49 and 1.29-1.97-fold increased comparative to those of the AEFC covering the same root areas. Electron microscopy revealed that NC was a functional tissue with insertion of collagen fibres perpendicularly to the long axis of the root. It can be concluded that under some experimental conditions formation of abundant amounts of NC can be achieved and that these results must be taken into account for a new approach in the treatment of periodontal disease.

Administration, Oral↗

Evidence that laminin-5 is a component of the tooth surface internal basal lamina, supporting epithelial cell adhesion.

Laminin-5 (Ln-5) is an extracellular matrix (ECM) glycoprotein found in epithelial basal laminae. We studied its expression on the surface of rat molars, in relationship to the location of the internal basal lamina (IBL) of the junctional epithelium (JE). In order to avoid disruption of the JE-tooth interface as much as possible, the surface of molars was prepared by mechanical removal of tissue debris and detergent/osmotic lysis of epithelial cell layers, and directly stained by immunohistochemistry, without sectioning. Antibodies to Ln-5 specifically stained a narrow band in the region of the cemento-enamel junction (CEJ), consistent with the expected location of the IBL. Western blotting of ECM material detergent--solubilized from the prepared tooth surfaces confirmed the molecular nature of Ln-5 identified by immunohistochemistry. By the use of a high-definition 3-D microscope, it appeared that Ln-5 coated the most apical part of the enamel and the most coronal portion of the cementum, on either side of the CEJ. In adhesion assays performed directly on tooth surfaces, epithelial cells adhered preferentially to the Ln-5 coated area of the tooth compared to the root surface, which is coated by other ECM components. Adhesion to the Ln-5 coated surface was specifically inhibited by a function-blocking monoclonal antibody to Ln-5. These results suggest that Ln-5 is a component of the IBL, and that it may be important in promoting adhesion of JE cells onto the tooth surface.

Animals↗

Accelerated alveolar bone loss in male HLA-B27 transgenic rats: adult onset.

OBJECTIVE AND BACKGROUND: HLA-B27 transgenic (TG) rats exhibit severe colitis, arthritis and other inflammatory lesions. Previous studies in female TG rats indicate that they develop severe alveolar bone loss (ABL). Lack of data on male TG rats has left open the question of possible hormonal/sex dependence for the observed ABL. The purpose of the present study was to assess the natural history of ABL in male HLA-B27 rats, compared to age- and sex-matched wild-type Fischer 344 (WT) rats. MATERIALS AND METHODS: Fourteen WT and 11 TG male rats, aged 7-8 weeks, were used. Sacrifice times occurred at 10, 22 and 35 weeks. Animal heads were defleshed and treated to remove organic material, and skulls were stained to locate the cemento-enamel junction. ABL was measured as exposed molar root surface area (mm2) on the right maxilla and right mandible. Blinded measurements were performed using a computer-assisted image analysis system. RESULTS: ABL for the entire TG group was significantly different from the WT group (p < 0.05). There was no significant difference in ABL between WT and TG rats at 10 weeks of age. At 22 and 35 weeks of age TG rats experienced 23% and 37% greater ABL than WT rats, respectively; these differences were statistically significant (p < 0.015). For both TG and WT animals, ABL was significantly different between the three age groups. CONCLUSIONS: These results, consistent with previous findings in female TG rats, suggest that the accelerated ABL found in TG rats is an adult-onset, age-dependent, and sex-independent process.

Age Factors↗

Observations on experimental marginal periodontitis in rats.

OBJECTIVE: The purpose of this study was to assess periodontal destruction following experimentally induced marginal periodontitis in rats by ligatures over a 60-day observation period. The extent to which the physiological movement of teeth influenced the effect of the ligatures was also examined. In addition, two methods for measuring bone loss in the defleshed jaw were compared. METHODS: Thirty-five male Sprague-Dawley rats (SD) were divided into five groups. Marginal periodontitis was induced by ligatures on the second maxillary molars. Rats were killed after 15, 30, and 60 days. Rats in the control group were killed on day 1 and day 60. Bone loss was determined with two different methods on the buccal and palatinal surfaces of the defleshed jaw. In the first method, the distance of the cementoenamel junction (CEJ) from the alveolar bone crest (ABC) was measured at different sites; in the second method, the area of the exposed root surface of the molars was measured. RESULTS: Comparison of the control groups from day 1 and day 60 using both measuring methods showed significant differences in bone loss. In the area where the ligature was located, test rats exhibited significantly greater bone loss than control rats. Comparison of control rats from day 1 with test rats from day 15 showed that the increase in bone loss between the groups within the area of the ligature was significantly greater than outside it. The age-dependent bone loss increases over the entire observation period of 60 days. The ligature-induced bone loss increased most from day 1 to day 15; on days 30 and 60, slighter increases in bone loss were observed. CONCLUSIONS: The application of this model can only be recommended for short (</=15 days) observation periods. The distance method should be preferred to the area method.

Age Factors↗

A comparison of root surface instrumentation using two piezoelectric ultrasonic scalers and a hand scaler in vivo.

BACKGROUND AND OBJECTIVE: This study compared the effectiveness of two piezoelectric ultrasonic scalers and a hand scaler for subgingival scaling and root planing in vivo. MATERIAL AND METHODS: Fifteen patients with advanced periodontal disease and with teeth scheduled for extraction were selected for this study. Three experimental groups of 10 teeth each were treated with one of two piezoelectric ultrasonic scalers [Vector scaler and Enac scaler] or with a hand scaler. Instrumentation was continued until the root surface felt hard and smooth to an explorer tip. The root surface characteristics after instrumentation were examined using scanning electron microscopy, and the amount of remaining calculus, roughness and loss of tooth substance were estimated using the remaining calculus index and roughness loss of tooth substance index. RESULTS: The remaining calculus index did not differ significantly among the three groups. The roughness loss of tooth substance index was significantly lower for the Vector scaler and Enac scaler groups than for the hand scaler group and also differed significantly between the Vector scaler and Enac scaler groups. CONCLUSION: This study suggests that the Vector scaler produces a smooth root surface with minimal loss of tooth substance. It is a reasonable choice for gentle periodontal maintenance treatment.

Dental Calculus↗

Possible application of transmitted laser light for the assessment of human pulpal vitality.

The purpose of this study was to determine whether use of transmitted laser light would enable a better assessment of human pulpal vitality than back-scattered light does (LDF: laser Doppler flowmetry). The experiments were carried out on ten upper central incisors in six subjects aged 23-28 years; five of the teeth were vital with no restoration, and five were non-vital. For use with transmitted laser light, the fibers within the probe of a conventional LDF apparatus were used, one for transmitting light onto the buccal surface, the other for receiving it at the palatal surface of the same tooth. For LDF, the probe was fixed at the buccal surface. Blood flow was measured at three different locations on each experimental tooth: the incisal third, the center and the cervical third of the tooth crown. In non-vital teeth, 1) output signals with transmitted laser light all registered zero, and no oscillation could be seen in recordings from any location on the tooth, but 2) LDF signals were above zero, there were regular oscillations related to heart rate, and passive increases in blood flow (corresponding to blood pressure increases) were recorded from both the center and the cervical third of the tooth, indicating that LDF registered blood flow of non-pulpal origin. In vital teeth, LDF signals were significantly higher than in non-vital teeth at each location on the tooth. At the central site on vital teeth, the output signals for transmitted laser light were about twice those seen with LDF, and passive blood flow changes corresponding to blood pressure increases were more clearly observed. These results indicated that transmitted laser light would be useful for the assessment of tooth pulp vitality both because the blood flow signals did not include flow of non-pulpal origin, and because its output signals and response to blood flow changes were clear and could easily be monitored.

Dental Pulp↗

Effect of chelating agents on the molecular composition and extent of decalcification at cervical, middle and apical root dentin locations.

The aim of this study was to investigate the interaction of two chelating agents used in endodontic treatment with dentin from different root locations. Standardized cervical, middle and apical root dentin specimens were prepared and subjected to treatment with 15% neutral EDTA and RCPrep. Following rinsing with water, dentin surfaces were studied by reflected light optical microscopy and micro-MIR FTIR spectroscopy, while the wash-off extracts were analyzed by atomic absorption spectrometry (AAS) to determine the content of calcium and phosphorus. Neutral EDTA removed the smear layer and opened tubules while RCPrep did not. FTIR measurements showed higher decalcification of dentin surfaces after neutral EDTA treatment although its effect was reduced at apical regions. AAS measurements of calcium and phosphorus confirmed the higher dentin dissolution potential of EDTA at cervical and middle root dentin locations. The results of the present study implied different reaction modes for the two chelating agents tested which might affect the efficiency of the chemo-mechanical preparation when these agents are used.

Analysis of Variance↗

Orthodontic extrusion of subgingivally fractured incisor before restoration. A case report: 3-years follow-up.

Orthodontic forced eruption may be a suitable approach without risking the esthetic appearance in tooth fracture below the gingival attachment or alveolar bone crest. Extrusion of such teeth allows elevating the fracture line above the epithelial attachment and so the proper finishing margins can be prepared. Restoration after orthodontic eruption may present a more conservative treatment choice in young patients compared with the prosthetic restoration after extraction. This case describes a multidisciplinary approach using the orthodontic forced eruption facilitating the composite restoration of a fractured upper permanent central incisor.

Child↗