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Leila Jahangiri

Publications and source records attributed to Leila Jahangiri.

9 recordsLinked to original sources
PubMed2005

Assessment of sensitivity and specificity of clinical evaluation of cast restoration marginal accuracy compared to stereomicroscopy.

STATEMENT OF PROBLEM: One of the most important criteria for the clinical acceptability and longevity of cast restorations is marginal adaptation. However, there is limited information on the accuracy of commonly practiced evaluation techniques. PURPOSE: This study assessed the effect of preparation design on marginal adaptation. In addition, sensitivity and specificity of clinical evaluations of marginal adaptations of cast restorations were assessed and compared to stereomicroscopy. MATERIAL AND METHODS: Three Ivorine molar teeth of differing designs were prepared: (1) a complete crown preparation with a chamfer finish line, (2) a complete crown preparation with a buccal shoulder and beveled finish line, and (3) a three-quarter crown preparation with proximal boxes and beveled finish line. Twenty-four castings (n = 8) were prepared (Ney technique casting metal). Twelve circumferential sites were identified for examination on each casting using a stereomicroscope, which was interpreted using software (Bioquant 98). The clinical examinations included explorer examination to detect marginal gap by tactile feel, followed by examination with a disclosing media (GC FitChecker). Chi-square tests of independence were used to evaluate the effect of preparation design and compare agreement between examination methods for detection of marginal gap size of greater than or equal to 30 microm (alpha=.05). RESULTS: The overall marginal adaptation of preparation designs was not significantly different. Results of explorer examination at 30-microm sensitivity and specificity were 46% and 97%, respectively. Similar values for disclosing media at 30 microm were 12% sensitivity and 97% specificity. The overall percent agreement with the stereomicroscope using the explorer was 58.3%, with 23.6% correct acceptance rate and 34.7% correct rejection rate. With respect to detection of marginal fit, the combination of disclosing material with explorer data did not yield significantly improved results (59.4%), as compared to explorer alone. A receiver operator characteristic curve yielded satisfactory sensitivity (0.8) and specificity (0.9) at a gap size value of 124 microm. CONCLUSION: Within the limitations of this study, the preparation design did not significantly affect the marginal adaptation. Clinical detection, with similar sensitivity and specificity as the stereomicroscope, occurred at marginal openings greater than or equal to 124 microm. Therefore, commonly used clinical evaluation techniques using an explorer and disclosing media may be inadequate for assessments of marginal accuracy.

Chi-Square Distribution↗
PubMed2005

Partial generation of periodontal ligament on endosseous dental implants in dogs.

OBJECTIVES: The objective of this pilot study was to investigate the feasibility of periodontal ligament (PDL) generation on an implant surface by approximating a tooth-to-implant contact using orthodontics. METHODS: Maxillary second premolars of six beagle dogs were extracted bilaterally. After 2 weeks of healing, hydroxyapatite (HA) coated titanium implants, 5 mm in length and 3.3 mm in diameter, were placed in the extraction sites. One side of the arch was used as control. Orthodontic tooth movement was initiated following implant placement to tip the first premolar roots into contact with the implant. This was achieved in 4-6 weeks as confirmed radiographically. Tooth-to-implant contact was maintained for further 6 weeks after which time, teeth were separated from implant contact orthodontically. After further 2 weeks of stabilization, the animals were sacrificed. Samples were analyzed by Faxitron radiographs before histology. Histology samples were prepared with Stevenel's Blue and Van Gieson stain and were subjected to polarized light microscopy. RESULTS: Histologic analysis revealed transfer and formation of PDL-like structure with formation of cellular cementum on the implant surfaces, in four out of six animals, where tooth-to-implant contact had been achieved. Direct bone-to-implant contact was noted in the areas coronal to the PDL-like tissue, an important sign to distinguish between PDL-like tissue and connective tissue that could originate from the coronal portion of a failing implant. Additionally, at the site of contact, the implant surface revealed some resorption of the HA coating. CONCLUSION: An animal model was established in which the proximity of tooth-to-implant contact lead to partial generation of PDL on a bioactive implant surface in four out of six animals.

Animals↗
PubMed2002

Onlay partial denture technique for assessment of adequate occlusal vertical dimension: a clinical report.

Clinical treatments that require restoration of occlusal vertical dimension pose a challenge to prosthodontists. This article describes the modification of existing removable partial dentures into onlay interim prostheses. This process allowed the patient's tolerance to the restored occlusal vertical dimension, esthetics, and phonetics to be evaluated before irreversible changes were made to the dentition.

Acrylic Resins↗
PubMed2002

Relationship between tooth shade value and skin color: an observational study.

STATEMENT OF PROBLEM: There is limited scientific information on the relationship between tooth shade and skin color. This lack of knowledge may impact the ability of the prosthodontist to select artificial teeth that complement the facial complexion of the patient. PURPOSE: This observational study explored the possibility of a relationship between tooth shade and skin color. MATERIALS AND METHODS: A total of 119 individuals aged 18 to 80 years participated in this observational study. Two investigators calibrated for examining tooth shade performed all examinations. A Vita-Lumin shade guide was used to examine either the maxillary right or left central incisor, one of which had to be restoration- and caries-free for study inclusion. Tooth shades were divided into 4 categories according to value, and skin tones were divided into 4 categories (fair, fair/medium, medium, and dark) with the use of L'Oreal True Illusion compact makeup shades as a guide. Categorical modeling with chi-square analysis and Fisher's exact tests was used to analyze the data (alpha=.05). RESULTS: No interaction among age, skin color, and tooth shade or gender, skin color, and tooth shade was found; however, age was associated with tooth shade (P<.001). Older persons were more likely to have teeth with lower values (darker). Among those aged 60 and older, 85% had teeth in the medium and low range values compared with 17% of those younger than 31. Significant tooth shade differences were discovered among patients with different skin colors (P<.05). Among those with low values (darker teeth), 50% were of fair complexion and 17% were of dark complexion (P<.001). CONCLUSION: Within the limitations of this study, tooth shade value and skin color were inversely related. Older adults were more likely to have darker teeth (lower value).

Adolescent↗