Maxillary Central Incisor Root Research Articles

TREATING INTERNAL RESORPTION USING A SYRINGEABLE COMPOSITE RESIN

Internal resorption is a pathological process initiated within the pulp space with the loss of dentin. It often is described as an oval shaped enlargement of the root canal space and usually is asymptomatic and detectable by routine radiographs. Treatment of internal resorption has included several materials--gutta-percha, zinc oxide eugenol and amalgam alloy. These materials do not provide strength to the tooth structure. A 29-year-old woman was referred to a dental clinic for treatment of a large internal resorptive defect in the coronal and middle one-third of the maxillary left central incisor root with no apparent periapical pathosis, as well as a large periapical radiolucency at the apex of the maxillary left lateral incisor that was associated with a necrotic pulp. The authors used a dual-cure syringable composite resin in conjunction with a bonding agent within the defect to treat it. This technique seals the dentinal tubules and strengthens the remaining tooth structure. It also improves the outcome of resorptive defects and reduces operators' chair time.

Class II, Division 1, case with multiple treatment challenges

This is a case report of a 23-year-old black woman with a skeletal Class II Division 1 malocclusion and an anterior open bite. The maxillary central incisor root was severely dilacerated, a maxillary lateral incisor and canine were transposed, a maxillary canine was impacted near the orbital rim, and a mandibular secong premolar was congenitally missing. Selective extractions and attention to detail provided outstanding occlusal function and improved facial esthetics. (Am J Orthod Dentofacial Orthop 1999;115:148-52)

Analysis of stress distribution in a vertically condensed maxillary central incisor root canal

In this study, the stress distribution in a maxillary central incisor subjected to an endodontic treatment was determined by using a three-dimensional finite-element method. The tooth had a variable root canal cross-sectional area, and the canal was assumed to be filled with vertical condensation. The Clinical practice was simulated by considering the obturation in successive stages. The main aim of the study was to investigate the possibility of fracture due to the obturation process. It was found that, within the limits of the study, the likelihood of a root fracture in such a process is a remote possibility.

Root fracture in endodontically treated teeth related to post selection and crown design

Standardized plastic analogues simulating an endodontically treated maxillary central incisor root were used to investigate the resistance to root fracture in endodontically treated teeth. Three different post and core systems were used: (1) cast post and core, (2) Para-Post Plus post, and (3) Flexi-Post post. The core build-up material selected in this study was Ketac Silver material, after which a crown preparation was made on each analogue. Two types of preparations were used: a wide chamfer margin (butt-joint) and a wide chamfer margin with a 1.0 mm circumferential bevel. An overcasting was fabricated and was permanently cemented on each preparation. Assemblies were subjected to an increasing lingual oblique force until fracture occurred. Results were tabulated using the analysis of variance (F test) and Student's t test. Beveled preparations with a concomitant final restoration provided a significant increased resistance to root fracture. Furthermore, vertical fracture occurred twice as often with nonbeveled preparations.

Patterns of incisor root resorption before and after orthodontic correction in cases with anterior open bites

External root resorption is a frequent iatrogenic consequence of orthodontic treatment, particularly in the maxillary anterior teeth. Since resorption also occurs is a normal function of aging and since altered behaviors such as bruxism and chronic nailbiting accelerate resorption even in the absence of treatment, it was hypothesized that the long-term orthopedic forces of tongue thrusting leading to anterior open bites would also enhance the rates of clastic activity. In a series of 32 adolescents with open bites, the roots of permanent maxillary central incisors were significantly shorter and exhibited higher modal grades of periapical resorption than a matched series with deep bites before treatment. The open bite group also had less facial bony support for these teeth. Both series experienced discernible resorption during full-banded treatment but to comparable extents so that, after active treatment, the open bite series continued to possess significantly greater degrees of resorption. Consequently, the oral forces leading to apertognathia are themselves destructive of root integrity and merit early recognition and interception.

Effects of sodium hypochlorite on soft tissues after its inadvertent injection beyond the root apex

The effects of an inadvertent injection of sodium hypochlorite into the cheek during irrigation of the right maxillary central incisor root canal are reported. The patient suffered from severe pain, edema, and necrosis of subcutaneous tissues and mucosa. Surgical intervention was necessary to contain the destructive process which extended from the upper lip to the right eye. The histopathological examination demonstrated the high cytotoxicity of sodium hypochlorite on vital tissue.

An evaluation of sealing ability of calcium hydroxide sealers

Solid core filling material such as gutta-percha has been used to fill the root canal in conjunction with a sealer to prevent apical leakage. The purpose of this study was to compare apical seal of five different root canal sealers. Sixty roots of maxillary central incisors were cleansed and shaped and randomly assigned to one of six groups of ten roots each. The root canals were obturated with gutta-percha and one of the sealers by the lateral-vertical condensation technique. Groups I, II, III, IV, and V consisted of roots in which the canal was filled with gutta-percha along with either Roth's sealer, AH26, Sealapex, CRCS, or Nogenol sealer, respectively. Group VI was filled with gutta-percha and without sealer to serve as a control. The access opening was filled with amalgam. Each tooth was then placed in a capped vial containing 2 × 2 inch gauze pads saturated with distilled water, and the sealer was allowed to set at 37° C in the humidor for 48 hours. The roots, except for the apical 2 mm, were coated with two layers of nail polish. The roots were stained with india ink, decalcified, dehydrated, and then placed in methylsalicylate to make them transparent. The leakage was measured with a filar micrometer eyepiece under a dissecting microscope. The mean apical leakage of six groups was as follows: I = 0.45 mm, II = 0.277 mm, III = 0.343 mm, IV = 0.263 mm, V = 0.336 mm, and VI = 2.310 mm. Results showed no significant difference in the apical seal produced by gutta-percha and the tested root canal sealers. Canals that were obturated with gutta-percha and without sealer showed significantly greater apical leakage ( P < 0.01).

Maxillary central incisor root length in orthodontically treated and untreated patients.

Maxillary central incisor root length in orthodontically treated and untreated patients.

An evaluation of maxillary central incisor root resorption comparing pre- and post-treatment periapical radiographs of patients treated with begg light wire orthodontic technic

Root resorption was determined by using preand posttreatment intraoral radiographs of sixty patients (thirty-six males and twenty-four females) selected at random. Thirty of these were nonextraction cases and thirty were extraction cases. A correction factor was used : x = Pretreatment length of tooth y = Pretreatment length of crown X Xl -7 = X 1= Posttreatment length of tooth “;;; y1 = P&treatment length of crown A comparison of the teeth in this study showed that the mean total of apical root resorption of the left central incisors was more than that of the right central incisors. This applied to both extraction and nonextraction cases. The findings demonstrated that there was no difference in the amount of apical root resorption in the sixty eases treated, either extraction or nonextraction, by the Begg light wire method. Seventy-one per cent of all teeth measured showed some degree of root absorption.

An analysis of stresses in a model of the periodontal ligament

The writers analyze the stresses in a model of the periodontal ligament of a maxillary central incisor. The model is assumed to be of paraboloidal shape, uniform thickness, and of a homogeneous, isotropic, and linearly elastic material. The inside surface of this paraboloidal shell is subject to rigid body displacement while the outside surface is assumed rigidly supported and stationary. The edge of the model is assumed to be stress free. A system of paraboloidal coordinates is developed, and this system is fitted to the shape of the root of a typical maxillary central incisor. The displacement functions obtained by solving the differential equations of equilibrium are used to determine the stresses at the inside and outside surfaces of the model ligament. These stresses are subject to superposition so that the stresses associated with any combination of applied forces and couples may be determined.

Unusually impacted permanent maxillary central incisor

The patient had a typical mixed denti­ tion with slight malpositioning of perma­ nent maxillary incisors, crowding of the mandibular incisors and neutroclusion of the posterior segments, containing decidu­ ous molars and cuspids as well as per­ manent first molars. The patient had ex­ cellent dental health; all deciduous teeth were sound, and the patient had only one small occlusal amalgam restoration, which was in the permanent maxillary first molar. The root of the deciduous maxillary right central incisor was still retained, and slight exudation of pus was observed when pressure was exerted on the sur­ rounding gingival tissues. The permanent right lateral incisor was tipped mesially, creating 2 mm. of space distal to it. The left central incisor was rotated slightly in a mesiopalatal direction. The space between these two teeth was 5 mm. (Fig. la ) . The incisal margin and root apex of the impacted incisor were palpated at the mucobuccal fold near the labial frenum and on the right side of the palate among the rugae, respectively.