Browsing by Subject "Molar"

Now showing 1 - 7 of 7
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    Buffered vs. Unbuffered Local Anesthesia in Mandibular Molars Diagnosed with Symptomatic Irreversible Pulpitis: A Controlled, Randomized, Double-Blind Study
    (2022) Alena, Peter; Spolnik, Kenneth; Ehrlich, Ygal; Warner, Ned
    Introduction: Profound pulpal anesthesia is not always adequate in mandibular teeth after the administration of local anesthesia, especially in the presence of irreversible pulpitis. Failure to achieve anesthesia has been seen in 30–80% of patients in teeth with a diagnosis of irreversible pulpitis. Onpharma™ developed an FDA-approved device that uses sodium bicarbonate to buffer a standard local anesthetic (LA) solution so that its pH may become closer to its pKa. Claims have been made that buffering a local anesthetic increases the anesthetic’s effect. Previous studies on the anesthetic efficacy of Onpharma’s Onset buffering system were inconclusive and may be dependent on the techniques used. Objectives: The aim of this study is to determine whether a buffered local anesthetic can lead to more profound and faster pulpal anesthesia in mandibular molars diagnosed with symptomatic irreversible pulpitis as compared to a standard, unbuffered local anesthetic. Materials and Methods: 40 total subjects completed the study. Screened and eligible subjects with a mandibular molar diagnosed with symptomatic irreversible pulpitis were randomly allocated into 2 groups so 1 group received a total of 3 cartridges of a standard, unbuffered 2% lidocaine with 1:100,000 epinephrine via inferior alveolar nerve block (IANB) followed by supplemental buccal and lingual infiltrations, while the other received the equivalent yet buffered formulation. An electronic pulp tester (EPT) was used to objectively determine baseline pulpal status of the affected tooth, followed by 2-minute interval testing following the administration of all local anesthesia. The onset of pulpal anesthesia was defined by the first of 2 consecutive EPT=80 readings, and the endodontic treatment could begin. Profound pulpal anesthesia was ultimately determined if the patient reported a comfortable pulpotomy as reflected on the Wong-Baker FACES Visual Analog Scale. Null Hypothesis 1: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia more profoundly using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Null hypothesis 2: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia faster using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Results: We observed a local anesthetic success rate of 45% in the buffered group, 70% in the unbuffered group, and ultimately 57.5% between both groups. The findings further indicate that the VAS scores after pulpotomy is significantly different between the 2 groups (p=0.019), with the unbuffered group having a more profound mean VAS score of 1.2 (as opposed to a buffered mean of 3.1). Regarding the time of onset for pulpal anesthesia, there was no statistically significant difference noted between the buffered and unbuffered groups. Conclusion: Based on the findings of this study, the null hypothesis 1 cannot be rejected since unbuffered 2% lidocaine with 1:100,000 epinephrine had a statistically significant increase in profound pulpal anesthesia compared to the buffered equivalent. The null hypothesis 2 cannot be rejected since there was no evidence of a significant difference in the time to pulpal anesthesia between the buffered and unbuffered groups.
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    Digital Radiographic Analysis of Mineral Density of Adjacent Alveolar Bone in Relation to the Molar Translation Rate After Use of Retromolar Implant Anchorage
    (1997) Sim, Yeongsuk; Roberts, W. Eugene; Analoui, Mostafa; Hohlt, William F.; Katona, Thomas R.; Shanks, James C., Jr.
    Molar translation using retromolar implants provides an unique opportunity to measure the rate of orthodontic tooth movement, because implants do not permit any reactive movement from the force. Contrast-corrected digital radiography was utilized to investigate the rate of molar translation related to the mineral density of adjacent alveolar bone. It was hypothesized that the rate of molar translation was inversely correlated with bone mineral density ahead of the moving tooth. Periapical radiographs were obtained every six months during 24 months of active treatment of eight patients (age: 24 to 48 years). Distance from three reference points (crown tip, mid-root, apex) and mineral density of four circular areas in front of the translating molar were analyzed for correlation. The primary method of analysis was the use of Pearson correlation coefficients between rate change and bone mineral density, and between rate change and age. The results showed that rate change of molar translation at the root apex was inversely correlated to the mineral density of adjacent alveolar bone. The correlations were not significant when examining the rate over the first six months; however, the correlations were significant after the second follow-up evaluation at 12 months. The correlation was also significant when using the overall means up to last follow-up visit. However, patient age was not significantly related to the rate of molar translation in this study.
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    The effect of untimely loss of deciduous molars on the development and eruption of the premolars
    (1964) Bowers, Donald Frederick, 1935-
    The effect of untimely loss of deciduous molars on the eruption and development of succedaneous premolars was serially studied in eight children in the mixed dentition stage from 45 degree cephalometric films made at three and six month intervals. Each child had one mandibular deciduous molar removed for reasons other than periapical infection and a lingual arch space maintainer provided. The premolar beneath the extracted molar served as the study tooth; its antimere, as the control tooth. Eruptive movement was measured as the distance between the cusp-tip of a premolar on a superpositioned initial tracing and the corresponding cusp-tip on successive films. Antero-posterior movement of premolars was evaluated on a composite tracing along grid lines oriented to a common base line. Tooth formation was assessed by the increase in root length on successive films. Variation was found in the amounts of eruptive movement and root growth during a three month interval, for all premolars within the sample, within an individual and for a single tooth. In no case did a control tooth erupt more than a study tooth in a given interval. The initial effect of deciduous molar loss on eruptive movement in this study appeared to be accelerative. Tooth development was not found to be effected. While moderate correlation was found between eruptive movement and root growth for all premolars, one process did not appear to be solely dependent on the other. A posterior component of eruptive movement was occasionally demonstrated but was not related to the extraction. The clinical value of this study is limited due to its small sample and short duration. Longer and more comprehensive studies of this problem are recommended.
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    Effects of rapid maxillary expansion on the cranial and circummaxillary sutures
    (Elsevier, 2011-10) Ghoneima, Ahmed; Abdel-Fattah, Ezzat; Hartsfield, James; El-Bedwehi, Ashraf; Kamel, Ayman; Kula, Katherine; Department of Orthodontics and Oral Facial Genetics, IU School of Dentistry
    INTRODUCTION: The aim of this study was to determine whether the orthopedic forces of rapid maxillary expansion cause significant quantitative changes in the cranial and the circummaxillary sutures. METHODS: Twenty patients (mean age, 12.3 ± 1.9 years) who required rapid maxillary expansion as a part of their comprehensive orthodontic treatment had preexpansion and postexpansion computed tomography scans. Ten cranial and circummaxillary sutures were located and measured on one of the axial, coronal, or sagittal sections of each patient's preexpansion and postexpansion computed tomography scans. Quantitative variables between the 2 measurements were compared by using the Wilcoxon signed rank test. A P value less than 0.05 was considered statistically significant. RESULTS: Rapid maxillary expansion produced significant width increases in the intermaxillary, internasal, maxillonasal, frontomaxillary, and frontonasal sutures, whereas the frontozygomatic, zygomaticomaxillary, zygomaticotemporal, and pterygomaxillary sutures showed nonsignificant changes. The greatest increase in width was recorded for the intermaxillary suture (1.7 ± 0.9 mm), followed by the internasal suture (0.6 ± 0.3 mm), and the maxillonasal suture (0.4 ± 0.2 mm). The midpalatal suture showed the greatest increase in width at the central incisor level (1.6 ± 0.8 mm) followed by the increases in width at the canine level (1.5 ± 0.8 mm) and the first molar level (1.2 ± 0.6 mm). CONCLUSIONS: Forces elicited by rapid maxillary expansion affect primarily the anterior sutures (intermaxillary and maxillary frontal nasal interfaces) compared with the posterior (zygomatic interface) craniofacial structures.
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    Effects of Various Thicknesses on Load to Fracture of Posterior CAD/CAM Lithium Disilicate Glass Ceramic Crowns Subjected to Cyclic Fatigue
    (2015) Al-Angari, Nadia; Platt, Jeffrey A.; Bottino, Marco C.; Haug, Steven P.; Brown, David T.; Levon, John A.
    Background: New glass ceramics and Computer-Aided Design/Computer Assisted Manufacture (CAD/CAM) have become common aspects of modern dentistry. The use of posterior ceramic crowns with a high level of esthetics, fabricated using the CAD/CAM technology is a current treatment modality. Several materials have been used to fabricate these crowns, including lithium disilicate glass-ceramics, which have not been fully investigated in the literature. Objective: to investigate the load to fracture of lithium disilicate glass ceramic posterior crowns fabricated by CAD/CAM technology with different material thicknesses adhesively cemented on epoxy resin. Methods: Four groups of different ceramic thicknesses (0.5 mm, 1 mm, 1.5 mm, and 2 mm) were fabricated by milling CAD/CAM lithium disilicate IPS emax CAD blocks. A total of 68 posterior crowns were surface treated and luted with a resin adhesive cement on an epoxy resin model. Samples were fatigued then loaded to fracture using a universal testing machine to test the fracture strength. Statistical comparisons between various crown thicknesses were performed using one-way ANOVA followed by Fisher's Protected Least Significant Differences. Results: There was a significant difference in the load-to-fracture (N) value for all comparisons of the four thickness groups (p < 0.0001), except 2 mm vs. 1.5 mm (p = 0.325). The mean load-to-fracture (N) was significantly higher for 2 mm than for 1 mm or 0.5 mm. Additionally, the mean load-to-fracture was significantly higher for 1.5 mm than for 1 mm or 0.5 mm. Furthermore, the mean load-to-fracture was significantly higher for 1 mm than for 0.5 mm. Conclusion: Within the limitation of this study, it is advisable for clinical applications to consider a crown thickness of 1.5 mm or greater of milled lithium disilicate for posterior single teeth.
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    Force Values and Rate of Distal Movement of the Mandibular First Permanent Molar
    (1959-11-01) Kuhn, Robert J.
    A method is described for the distal replacement of mesially tipped mandibular first permanent molars in children nine to thirteen years of age. The study was designed to determine the rate of movement and pain response of this tooth when relatively light specified forces were applied for distal movement. This study was undertaken in the light of recent evidence which suggests that forces many times lighter than those currently employed may enhance rate of movement, diminish the amount of root and periodontal damage, and practically eliminate pain usually associated with tooth movement. The sample was composed of children who had prematively lost deciduous mandibular second molars with resultant mesial tipping of the first permanent molar. There were eighteen cases in the sample of fifteen children, three of the children exhibiting bilateral loss. The method of movement employed a sine loop helical torsion spring attached to a soldered lingual appliance to effect distal molar movement. This appliance was so fabricated to utilize all of the teeth anterior to the primary second molar space as anchorage. Extensive records were taken before treatment began, during active treatment, and at the time of retention. These included models, lateral headplates, periapical radiographs, oriented occlusal radiographs, and direct divider measurement in the mouth. The children were routinely examined every four to ten days and appropriate records and measurements taken at these appointments. It was found in those cases in which under 80 grams had been applied to the teeth there was one pattern of movement while in those above 100 grams another general type was observed. In the below 80 gram group there was a relatively large (0.69 mm.) initial increment of space opening in the first week followed by a one – two week latent period of non-movement. Movement then continued at an average of 0.22 mm/week. The 100 gram group exhibited a very small initial movement (0.27 mm) followed by a two-three week latent period. Movement then continued at a rather rapid rate, (0.39 mm/week). Flaring of the anchorage united was noted in all but one case. The amount ranged between 1 and 2 mm. in four to six weeks. The cases above 100 grams appeared to show the largest amount of flaring. Pain usually associated with tooth movement was non-existent in the patients where below 70 grams of force was applied. The intensity of the pain response in the cases above 70 grams (70 – 194) appeared generally to coincide with the magnitude of force application. The many difficulties and variables associated with distal mandibular molar movement are discussed in detail. These include tooth inclination, occlusion and interlocking, relationship of the second permanent molar, and root configuration. Based on the results of this study, it is suggested that threshold forces for tooth movement may be non-existent and that any force if allowed to remain on a given tooth for a sufficient length of time will elicit tooth movement. The evidence shown both in this study and by other investigators point to the possibility of an optimal range of force for tooth movement.
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    A Histologic and Cephalometric Investigation of Premolar Intrusion in the Macaque Speciosa Monkey
    (1965) Dellinger, Eugene L.
    It has been debated as to whether teeth may actually be intruded in their alveoli. This study was designed to measure the intrusive movement and histologic response of specific teeth to a known intrusive force. Four Macaque speciosa monkeys were used. The animals corresponded in age to a 12-14 year old human being. Intrusive forces of either 10, 50, 100, or 300 grams were placed on the maxillary first premolars; each force value was held constant during the duration of the experiment, which was 60 days. Maxillary first molars were used as anchorage. Cephalometric headplates proved that all force values were capable of giving intrusion. The 50 gram forces, however, gave the most efficient intrusion. Histologic sections were made on all experimental teeth. 300 and 100 gram forces gave excessive root resorption but the 50 and 10 gram force values elicited only slight root resorption. Root resorption seemed to be directly related to excessive force. The amount of intrusion was not related to a loss of root structure. Bone resorption appeared to allow the intrusion of teeth with minimal tissue damage if proper force values were used.