SEARCH · PubMed Health

Results for “Tooth”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

PubMed1993

Histological studies on the effects of tooth brushing on repair of alveolar bone after periodontal osseous surgery in the rat incisor.

The purpose of this study was to elucidate the effects of tooth brushing on repair of alveolar bone after periodontal osseous surgery in the labial alveolar bone of rat incisor. The surgery was performed on 24 Wistar rats divided into 2 groups: the experimental group, which was subjected to tooth brushing, and the control group, which was not. In the experimental group, daily tooth brushing was initiated at 4 weeks after surgery. The rats were sacrificed after 1 or 2 weeks of tooth brushing. Microradiographic, light and fluorescence microscopic examinations were made of sections of the alveolar bone and its surrounding tissue. After 1 week of tooth brushing, callus with a low degree of mineralization and with large, irregularly arranged, young osteocytes appeared in the superficial layer and crest portion of alveolar bone in the brushing region. Numerous blood vessels had invaded the callus. In this region, the height of osteoblasts on the callus surface increased. At the alveolar crest region, the callus was approximately 3 times thicker than in the superficial region. After 2 weeks of tooth brushing, modification had occurred in the callus; this region had evolved into developed bone with a compact matrix. These findings suggest that the intermittent mechanical stress of tooth brushing is useful in activating the cells of the alveolar periosteum and in stimulating bone formation.

Alveolar Process↗

PubMed1996

Permanent tooth calcification in chimpanzees (Pan troglodytes): patterns and polymorphisms.

Tooth calcification is an important developmental marker for use in constructing models for early hominid life history, particularly for its application to the fossil record. As chimpanzees are commonly utilized in interspecific comparisons in such research, this study aims to improve available baseline data for tooth calcification patterns in chimpanzees (Pan troglodytes), and to quantify basic patterns and polymorphisms. We present an analysis of developmental patterns for the left mandibular dentition (I1-M3) based on intraoral radiographs obtained from a cross-sectional sample of chimpanzees (58 males, 60 females) housed at LEMSIP (NYU Medical Center) and Yerkes (Emory University). No significant differences with previous descriptions of the basic sequences of tooth calcification in chimpanzees were found, but variation in such patterns was documented for the first time. In the overall sequence, polymorphisms between the canine and the group (M2 P4 P3) reached significant levels. This is due to the relative delay in canine crown formation compared to other teeth. Differences in the basic sequence between males and females were recorded, but are due to minor shifts in the percentages of occurrence for polymorphic sequences which are common to both genders. Perhaps our most important findings are that a) different polymorphic sequences occur in tooth calcification and tooth emergence in chimpanzees, and b) developmental relationships among teeth fluctuate throughout tooth calcification. Thus, characterizations of dental developmental patterns based on particular stages of development cannot necessarily be extrapolated to other stages without supporting data.

Animals↗

PubMed2001

Expression of cathepsin K mRNA and protein in odontoclasts after experimental tooth movement in the mouse maxilla by in situ hybridization and immunoelectron microscopy.

This study demonstrated the simultaneous expression of cathepsin K (CK) mRNA by in situ hybridization and CK protein by immunoelectron microscopy in odontoclasts in mouse maxillae after experimental tooth movement. On the pressure side (the area under pressure during tooth movement), CK mRNA was detected in odontoclasts in resorption lacunae in the tooth root, in osteoclasts in bone resorption lacuane, and in fibroblasts in the periodontal ligament. Using electron microscopy, CK protein was detected at the apex of odontoclasts, intracellularly in vesicles and granules, and extracellularly in irregularly shaped vacuoles (extracellular spaces), on the plasma membrane of the ruffled border, and on and between typical striated type I collagen fibrils in the lacunae. These vesicles and granules appeared to fuse with irregular vacuoles containing CK-positive fragmented fibril-like structures close to the ruffled border. In the basolateral portion of odontoclasts, small amounts of CK-positive rough endoplasmic reticulum (ER) were found. CK-positive intracellular vacuoles (not extracellular spaces) also appeared to fuse with the vesicles and granules. However, these fused organelles rarely contained fragmented fibril-like structures. They are probably endolysosomes. The distribution of CK in odontoclasts was similar to that previously seen in osteoclasts. Furthermore, CK-positive fibril-like structures were found in the vacuoles of fibroblasts. These results indicated that during tooth movement CK is synthesized in odontoclasts on the pressure side and secreted into the tooth resorption lacunae. Therefore, CK may take part in the degradation of the dentin matrix (type I collagen fibrils and non-collagenous protein) of the tooth root, and in the subsequent intracellular degradation of endocytosed fragmented fibril-like structures in endolysosomes.

Animals↗

PubMed1976

The cracked-tooth syndrome and fractured posterior cusp.

1. Even from such a small sample as that reported in this study, it is evident that the fractured cusp and cracked-tooth syndrome are common problems. The large number of fractured cusps compared to the cracked-tooth syndrome suggests that some of the cases of fractured cusp could have been diagnosed earlier. 2. It is most important that dentists be aware of the cracked-tooth syndrome in order to relieve the patient's discomfort, prevent the possible eventual loss of the pulp or tooth, and avoid unnecessary and possibly damaging treatment for misdiagnosed facial pain. 3. Conservation of tooth structure in restorative procedures is most necessary in order to prevent the cracked-tooth syndrome or fractured posterior cusp.

Cracked Tooth Syndrome↗

PubMed1986

Effects of diazepam on orthodontic tooth movement and alveolar bone cAMP levels in cats.

Cyclic AMP has been suggested as a possible intracellular mediator in bone remodeling during tooth movement. Accordingly, an increase in the level of this nucleotide should result in faster tooth movement. Breakdown of cAMP was inhibited by administration of diazepam in eight cats undergoing orthodontic tooth movement; another matched group of eight animals served as controls. Orthodontic appliances consisted of coil springs stretching between the right side maxillary and mandibular canines and third premolars. The data for tooth movement and cAMP concentrations were analyzed by repeated measures factorial analyses of variance. The results indicated that administration of diazepam increased the rate of tooth movement at P less than 0.0005 and, interestingly, although diazepam had no effect on undisturbed tissues, it lowered the cAMP levels in the periodontal tissues of orthodontically moved teeth at P less than 0.01. On the basis of these results, it was concluded that the concentration of cAMP did not correlate with bone remodeling in this model and perhaps should not be used as an index of periodontal-tissue response during orthodontic tooth movement.

Alveolar Process↗

PubMed1991

Patterns of initial tooth displacements associated with various root lengths and alveolar bone heights.

The present study was designed to investigate the nature of initial tooth displacements associated with varying root lengths and alveolar bone heights. A three-dimensional model of the upper central incisor was developed for the finite element analysis. Tooth displacements were determined at various levels of the tooth and the apicogingival levels of the center of resistance and centers of rotation were calculated. The results showed that moment-to-force values at the bracket level for translation of a tooth decreased with shorter root length and increased with lower alveolar bone height. In addition, apicogingival levels of the center of resistance shifted more gingivally to the cervix, or the alveolar crest with a shorter root. Alveolar bone loss also shifted the center of resistance toward the alveolar crest, whereas its position was more apical relative to the alveolar bone heights exhibited very slight changes in both cases. The centers of rotation from a single force varied substantially with a short root and alveolar bone loss. However, the relative distances of the centers of rotation from the alveolar crest in comparison with the alveolar bone heights were constant at 0.4 mm, with variations in the root length and alveolar bone height. Because this study showed that root length and alveolar bone height affect the patterns of initial tooth displacements both in the center of resistance and the centers of rotation and also in the amount of displacement, forces applied during orthodontic treatment should take into consideration the anatomic variations in the root length and alveolar bone height so as to produce optimal and desired tooth movement.

Alveolar Process↗

PubMed2004

Tooth-width ratio discrepancies in a sample of Peruvian adolescents.

Previous studies have demonstrated different tooth-width ratio discrepancies in different populations. The objective of this study was to determine maxillary to mandibular tooth-size ratios in a Peruvian sample; 200 children were selected who had complete permanent dentition, without clinically visible dental caries or proximal restorations, and no previous or active orthodontic treatment. Their dental casts were measured to the nearest 0.1 mm with a sliding caliper and a Vernier scale. The Kolmogorov-Smirnov test, t test, and Pearson correlation test were used. No significant differences were found in anterior (P =.713) and total (P =.174) tooth-size sums according to sex. The anterior tooth-width ratios were 77.78% +/- 2.44% for females and 78.39% +/- 2.81% for males (P =.103). The total ratios were 90.79% +/- 1.71% for females and 91.33% +/- 2.07% for males (P =.048). For this reason, the combined male and female anterior total ratio was calculated (78.09 +/- 2.64%). There were clinically significant tooth-size discrepancies in almost one third of the sample. The 2-standard deviation range from the Bolton standard did not predict clinically significant anterior and total tooth-width ratio discrepancies.

Adolescent↗

PubMed2003

Deciduous tooth crown size in prematurely born children.

AIM: The purpose of our study was to examine deciduous tooth crown size in preterm children. SUBJECTS AND METHODS: The subjects consisted of 328 prematurely born (< 37 gestational weeks) white and black children and 1804 controls, who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the 1960s and 1970s. Documents of the present research consisted of dental casts of the 6-12 years old children. Tooth crown measurements on canines and molars were performed on the dental casts with an electronic measuring device according to precise definitions generally quoted in the anthropological and genetic literature. For the results, the preterm and control groups were divided by sex and race. RESULTS: There were both increased and decreased mesiodistal and labiolingual tooth crown dimensions in prematurely born children, but no significant differences between the study groups was found. CONCLUSIONS: The findings of the present research suggest that short gestation is not associated with reduced deciduous tooth crown size as suggested by earlier studies and are parallel with our previous results of permanent tooth crown dimensions in prematurely born children. Boys showed clearly larger tooth crown sizes than girls within all preterm and control groups. This indicates that sexual dimorphism is apparent in its final form beginning some months after birth.

Adolescent↗

PubMed2004

Tooth colour: a review of the literature.

OBJECTIVES: To review current knowledge with respect to tooth colour and its measurement. METHODS: 'Medline' database for the period 1966 to the present day and 'ISI Web of Science' database for the period 1974 to the present day were searched electronically with key words tooth, teeth, colour and color. CONCLUSIONS: The colour and appearance of teeth is a complex phenomenon, with many factors such as lighting conditions, translucency, opacity, light scattering, gloss and the human eye and brain influencing the overall perception of tooth colour. The measurement of tooth colour is possible via a number of methods including visual assessment with shade guides, spectrophotometry, colourimetry and computer analysis of digital images. These methods have successfully been used to measure longitudinal tooth colour changes when the dentition has undergone tooth whitening procedures.

Color↗

PubMed2004

The effectiveness of auxiliary features on a tooth preparation with inadequate resistance form.

STATEMENT OF PROBLEM: No study has evaluated the efficacy of auxiliary tooth preparation elements for crowns with originally reduced resistance form. PURPOSE: This study evaluated the effects of different auxiliary preparation features on the resistance form of crowns with reduced axial wall and total occlusal convergence. MATERIAL AND METHODS: An Ivorine tooth was prepared on a milling machine with 20-degree total occlusal convergence (TOC), 2.5 mm of occlusocervical dimension, and a shoulder finish line. This design lacked geometric resistance form. The crown preparation was subsequently modified to include mesiodistal grooves, mesiodistal boxes, buccolingual grooves, occlusal inclined planes, an occlusal isthmus, and reduced TOC in the axial wall from 20 to 8 degrees TOC in the cervical 1.5 mm of the axial wall. The grooves and boxes were placed into the tooth with the same 20-degree TOC as the initial axial walls. Ten standardized metal dies were used for each preparation design. Standardized complete metal crowns were fabricated for all specimens. The metal crowns were cemented on metal dies with resin-modified glass ionomer cement. A strain gauge was placed at the mid-lingual cervical area of each crown preparation margin. The resistance of each specimen was evaluated when force was applied at a 45-degree angulation to the long axis of the die in a lingual to buccal direction. The peak loads during crown dislodgment, as well as the tensile stress at the mid-lingual cervical area, were measured using a universal testing machine (Kgs) for each specimen. The control group consisted of 10 dies, with the original crown preparation having no geometric resistance form and no auxiliary preparation features. Strain gauges provided the force (Kgs) that resulted in electric currency disrupt at the crown/die interface, thus providing data regarding the force required for slight crown micromovement (2 microm). Data between control and experimental groups were compared using the Mann-Whitney U test (alpha=.05). RESULTS: Proximal grooves, proximal boxes, buccolingual grooves, occlusal inclined planes, and occlusal isthmuses were not effective at increasing a crown's resistance to dislodgement when the tooth preparation lacked resistance. The only crown modification that offered enhanced resistance form when compared with the control group was the reduced TOC in the cervical half of the axial wall. CONCLUSION: Within the limitations of this in vitro study the crown preparation modification that significantly enhanced the resistance form of a compromised tooth preparation was reducing the TOC at the cervical aspect of the axial wall. Placing auxiliary retentive features such as grooves and boxes into a compromised tooth preparation (2.5 mm occlusocervical dimension and 20-degree TOC) was not effective when these retentive features possessed the same 20-degree TOC as the prepared axial walls.

Cementation↗

PubMed1997

A comparative prospective clinical study of two single-tooth implants: a preliminary report of 102 implants.

STATEMENT OF PROBLEM: Treatment of tooth loss in the anterior maxilla can involve difficult functional, esthetic, and psychologic problems, especially in young patients with otherwise good dentition. PURPOSE: The purpose of this study was to provide a preliminary comparative evaluation of two implants (ITI and Astra) in single-tooth restorations. MATERIAL AND METHODS: This prospective study of 102 single-tooth replacements with 56 ITI and 46 Astra dental implants was performed in 82 patients at the Finnish Student Health Service Foundation. One Astra implant was lost before loading. The overall survival rate of the implants was 97.8% for Astra implants and 100% for the ITI system. After the initial healing period of at least 6 months, the remaining 101 implants (56 ITI, 45 Astra) were free of periimplant infection and revealed no detectable mobility. Radiographs did not reveal signs of periimplant radiolucencies. All 101 implants received single-tooth crowns. RESULTS: Periimplant parameters and acceptable implant function were examined and demonstrated satisfactory results with preestablished clinical parameters and radiographs at 1 year. During the observation time the mean marginal bone loss was 0.13 mm with Astra implants and 0.11 mm with ITI implants. Subjectively all patients were satisfied with their single-tooth restorations supported by either ITI or Astra dental implants. CONCLUSION: The favorable results of this short-term study support the application of the two implant systems for single-tooth restorations, especially in the anterior region of the maxilla.

Adolescent↗

PubMed1999

Retention of adhesive cement on the tooth surface after crown cementation.

STATEMENT OF PROBLEM: Adhesive cements increase crown retention, but it is unknown if traces of cement remain undetected on the tooth surface after clinical removal of excess cement, which could exacerbate plaque retention. PURPOSE: This study measured the surface area, volume, mean depth, and maximum depth of a resin composite and a compomer luting cement left adherent on the tooth surface after removal of excess cement, as judged clinically. METHODS AND MATERIAL: Four groups of specimens (n = 48) were prepared for full coverage crowns: group AC bonding alloy with chamfer finish line, group G gold alloy with chamfer finish line, group PC porcelain with a chamfer finish line, and group PS porcelain with a shoulder finish line. Two profiles of the mesial and distal surfaces of the teeth were carried out: (1) tooth with crown seated but not cemented and (2) tooth with the crown cemented in place. Two cements and 2 methods of cement removal were studied. RESULTS: A 4-way analysis of variance for cement, crown type, method of removal, and tooth surface morphology showed that significantly greater volumes and mean depth, but not surface areas, of resin composite cement remained adherent than compomer cement (P<.05). Among crown types, significant differences were found for cement volume (group G>AC, G>PC, G>PS), cement surface area (group AC>PC, G>PC, G>PS), and maximum cement depth (group G>AC). There was no significant difference between the 2 methods of cement removal. Significantly larger surface areas and maximum depths of cement were retained on the anatomically grooved mesial surface of the maxillary first premolars than on the ungrooved distal surface. CONCLUSION: Subclinical cement retention occurred after crown cementation, which was influenced by cement, crown type, and tooth surface morphology but not method of cement removal.

Adhesives↗

PubMed1988

The effect of age on tooth movement and mineral density in the alveolar tissues of the rat.

A comparison of tooth movement cycles and changes in alveolar tissue mineral densities was made between young (21 to 28 days old) and adult (90 to 100 days old) rats. An initial 60-g mesial tipping force was applied to the maxillary first molars; tooth movement was estimated by measuring the opening between first and second molars, and tissue mineral density by sample ash weight per cubic centimeter. A characteristic three-part tooth movement cycle was found in both groups of rats. This cycle consists of an early "instantaneous" movement that is a function of the viscoelastic properties of the tissues, a delay period during which little tooth movement occurs due to hyalinization and undermining resorption, and a late period during which bone remodeling and tooth movement occur. Compared with the adult group, the amount of "instantaneous" movement in the young rats was greater (P less than 0.001), the delay period was shorter, and the rate of late tooth movement was faster (P less than 0.001). The young rats had significantly lower (P less than 0.05) mineral densities before orthodontic treatment. Both groups experienced a slight but insignificant increase in density followed by rapid declines to a nadir that was not different between the groups. The young rats reached this point by day 5 and the adults by day 7. The point of lowest mineral density occurred in the treated alveolar tissues toward the end of the delay period for each group and was followed by a return to control values at rates that were not significantly different between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed2004

Effectiveness of an educational program in reducing the incidence of wrong-site tooth extraction.

OBJECTIVES: The aim of the study was to investigate the effectiveness of an educational program on the reduction of the incidence of wrong-site tooth extraction at the outpatient department of a university hospital in Taiwan. STUDY DESIGN: Data collected from cases of wrong-site tooth extraction during 1996 to 1998 were used to develop a specific educational intervention that was implemented from 1999 to 2001. The annual incidence of erroneous extraction was compared between the preintervention and intervention periods. The factors contributing to wrong tooth extraction were also analyzed. RESULTS: The annual incidence rates of erroneous extraction from 1996 to 1998 were 0.026%, 0.025%, and 0.046%, respectively. During the intervention period from 1999 to 2001, wrong-site tooth extraction did not occur at the department. There was a significant difference in the incidence of erroneous extraction between the preintervention and intervention periods (P<.01). Cognitive failure was the most frequent form of active failure responsible for wrong-site tooth extraction, whereas communication and training were found to be major latent factors contributing to these errors. CONCLUSIONS: Our results suggest the effectiveness of an educational program comprising case-based materials, information feedback, and clinical guidelines in reducing the incidence of wrong-site tooth extraction.

Adolescent↗

PubMed1999

Implant supported single-tooth replacements compared to contralateral natural teeth. Crown and soft tissue dimensions.

The aim of this study was to make a comparative evaluation of crown and soft tissue dimensions between implant-supported single-tooth replacements and the contralateral natural tooth. Twenty patients, who had been treated with an implant-supported single-tooth replacement in the esthetic zone of the maxillary jaw and had i) a non-restored contralateral natural tooth and ii) completed the implant-supported crown restoration at least 6 months prior to the scheduled follow-up examination, were included in the study. At the re-examination various variables describing crown form, soft tissue dimensions and soft tissue conditions were assessed. In addition, the patient's overall satisfaction with the esthetic outcome of the implant-supported single crown was scored using a Visual Analogue Scale (VAS). In 12 of the subjects clinical photographs were available from the time of crown insertion for evaluation of longitudinal alterations of the papilla height. The results revealed that, in comparison to the contralateral natural crown, the implant supported crown i) was longer, ii) had a smaller facio-lingual width, iii) was bordered by a thicker facial mucosa, iv) had a lower height of the distal papilla, v) showed a higher frequency of mucositis and bleeding on probing and vi) showed greater probing depths. The longitudinal evaluation of the papillae adjacent to the implant crown showed an improved proximal soft tissue fill at the follow-up examination. The VAS scoring of the patients' satisfaction with the appearance of their single implant-supported restorations revealed a median value of 96% with a range from 70 to 100%. Hence, observed differences in clinical crown height and soft tissue topography between implant-supported single-tooth replacements and the contralateral natural tooth may in most patients be of minor importance for the appreciation of the esthetic outcome of implant therapy.

Adolescent↗

PubMed2001

Freestanding and tooth-implant connected prostheses in the treatment of partially edentulous patients. Part I: An up to 15-years clinical evaluation.

In 123 patients, 339 implants were connected to 313 teeth by means of fixed partial prostheses (test) and followed up for 1.5-15 years (mean: 6.5). In another ad random selected 123 patients, 329 implants were connected to each other by means of 123 freestanding fixed partial prostheses (control) and were followed up for 1.3-14.5 years (mean: 6.2). The aim of this study was to compare both treatment modalities with each other based on implant, tooth and prosthesis complications. The cumulative implant success, based on implant immobility and/or lack of implant fractures after loading, in the test and control groups amounted to 95% and 98.5%, respectively. Although in the test group 10 implants versus only 1 in the control group failed, a regression analysis of the survival data, based on the cox proportional hazards model, revealed no significant difference. In the test group periapical lesions (3.5%), tooth fracture (0.6%) and tooth extraction due to fatal decay or periodontitis (1%) were observed, besides tooth intrusion (3.4%) and crown cement failure (8%). Framework fracture occurred in 3 patients. In the control group, only 2 abutment screws fractured. The treatment of partial edentulism by means of oral implants was beneficial for our patients. Because of a clear tendency of more implant failures (mobility or fractures) and tooth complications in the tooth-implant connected prostheses, the freestanding solution is the primary option to be considered. To avoid intrusion of abutment teeth, the connection, if made, should be completely rigid.

Adult↗

PubMed1999

Effect of appliance reactivation after decay of initial activation on osteoclasts, tooth movement, and root resorption.

Clinical orthodontists frequently reactivate appliances following decay. Studies of tooth movement and tissue responses following reactivations indicate that linear tooth movement and rapid recruitment of osteoclasts can be achieved if reactivation is timed to coincide with the latter part of the bone remodeling cycle initiated by the first activation. Both can be delayed if reactivations are timed for the early part of the previous cycle. The objective of this study was to examine tooth movement, root resorption, and osteoclast recruitment following appliance reactivation after the first activation had decayed. Bilateral orthodontic appliances were activated with 40 cN in 144 rats to mesially tip the maxillary molars. After 16 days, rats were randomized into two groups of 72. In group 1, appliances were reactivated in precisely the same manner as the first activation. In group 2, appliances were sham-reactivated. Rats were sacrificed at 1, 3, 5, 7, 10, and 14 days. Orthodontic movement was measured cephalometrically; changes in osteoclasts and root resorption were assessed at both compression and tension sites histomorphometrically; tartrate-resistant acid phosphatase (TRAP) was measured in alveolar bone and serum biochemically. Orthodontic tooth movement was linear in group 1, but osteoclasts required 3 to 5 days to appear. There were no group- or time-related differences in root resorption. Bone TRAP levels were elevated in both groups but dropped significantly (p<0.01) in group 2 at day 7. Appliance reactivations that followed decay of the first activation produced efficient tooth movement without increased risk of root resorption, but these changes were not accompanied by rapid osteoclast recruitment at compression sites. Timing appliance reactivations for the latter portion of the previous bone remodeling cycle could have significant clinical advantages because the delay period seen in tooth movement following a single activation or short-term reactivation can be avoided.

Activator Appliances↗

PubMed2000

Mesiodistal crown dimensions and tooth size discrepancy of the permanent dentition of Dominican Americans.

The purpose of the study was to establish normative data on the mesiodistal crown dimensions of Americans of Dominican background. The Bolton tooth size analysis was performed on a sample of 54 Dominican Americans. The mean, range and standard deviation were calculated for the size of the teeth, and a coefficient of variation was obtained for the tooth size ratio. A 2-sample t-test was used to test for the statistical difference between means. In general, the values obtained for the Dominican American sample closely resembled previous data available for the African American population. The tooth size ratios obtained were compared to the Bolton ratios. The overall ratio was found to be 91.3, equivalent to the Bolton overall ratio, whereas the anterior ratio was 78.1, larger than the 77.1 Bolton ratio. The frequency of tooth size discrepancy outside 2 standard deviations from the Bolton mean was also calculated. An overall tooth size discrepancy was found in 11% of our sample, and 28% of the sample presented an anterior tooth size discrepancy.

Adult↗