Maxillary Incisor Root Research Articles

Comparison of apical and coronal sealing in canals having tapered cones prepared with a rotary NiTi system and stainless steel instruments

The purpose of this study was to compare the sealing ability of different tapered gutta percha cones that were used with lateral compaction and single cones in canals prepared with various root canal instruments. One hundred extracted maxillary incisor roots were used. In group 1, 30 roots were prepared with stainless steel instruments (SS) and then filled by the lateral compaction technique using .02 tapered master cones. In group 2, 30 roots were prepared with ProFile nickel titanium instruments (NiTi) and filled in the same way as group 1. In group 3, 30 roots were filled by the single cone technique using 0.06 tapered gutta-percha cones. The remaining 10 teeth were taken as two control groups. Apical and coronal leakage was evaluated using the fluid filtration model. Considering the effects of the instrumentation, no statistically significant differences were found between the groups prepared with SS and NiTi (P > 0.05). When the effects of obturation technique were taken into consideration, the ProFile instruments and lateral compaction resulted in significantly less coronal leakage than the SS instruments and lateral compaction (P < 0.05). There were no significant differences in apical leakage among any of the groups (P > 0.05).

Orthodontic and Nonorthodontic Root Resorption: Their Impact on Clinical Dental Practice

Occasionally, general dentists are challenged with providing restorative treatment for a postorthodontic patient who has had moderate to severe root resorption. When this happens, a number of questions about the cause of such resorption and the appropriate treatment arise in the dentist's mind. This article will describe the orthodontic and restorative management of three patients with severe maxillary incisor root resorption, provide a thorough discussion of the currently available literature on the topic of root resorption, and answer clinical questions regarding this relatively infrequent but devastating sequel to orthodontic treatment.

The effect of spreader size on fracture resistance of maxillary incisor roots

To assess the effect of spreader size used during cold lateral compaction of gutta-percha on fracture resistance of roots in maxillary incisor teeth. The crowns of 50 human maxillary incisor teeth having no carious lesions, no fracture or crazing were resected 2 mm coronal to the cemento-enamel junction. The root canals of the teeth were prepared as follows: Group 1: No canal preparation. Group 2: Preparation using the stepback technique to a size 40 master apical file. Group 3: Canal preparation to size 40 and filling with laterally compacted gutta-percha; the first spreader used was equal to size 40. Group 4: Same as group 3 except the first spreader was equal to size 35. Group 5: Same as group 3 except the first spreader was equal to size 25. For each root, a simulated periodontal ligament was prepared. The roots were than mounted in polyester resin and fractured vertically on a universal testing machine (Shimadzu, Tokyo, Japan). The fracture values of teeth were analysed using Kruskal-Wallis and Mann-Whitney U-tests (P = 0.05). The uninstrumented group had the highest fracture resistance; instrumented, but unfilled roots, demonstrated the lowest resistance values (P = 0.009). There were no differences between the uninstrumented group and group 5 in which a size 25 spreader was used during filling. Use of spreaders larger than size 25 caused a significant reduction in fracture resistance of roots (P < 0.05). Spreader size used during lateral compaction of gutta-percha can affect the fracture resistance of roots in extracted teeth.

Morphometric study of length and grooves of maxillary lateral incisor roots

Root grooves are considered a risk factor for periodontal disease. The purpose of this study was to measure the length of the root of maxillary lateral incisors (MLI), as well as the width and depth of the concavities of their proximal surfaces, and also to determine the prevalence of palato-gingival grooves. the width and depth of root concavities, as well as root length were evaluated in 73 MLI. All teeth were measured using a digital contour measuring instrument for the root grooves and a caliper for evaluating root length. After statistical analysis (p<0.05) it was possible to confirm: the mean root length on its mesial surface was (15.47+/-1.72 mm), on its distal surface (14.99+/-1.70 mm), on its buccal surface (13.10+/-1.69 mm) and on its lingual surface (12.71+/-1.53 mm); concavities were present in 100% of the samples; concavities were found 2mm, coronally from the CEJ, at the CEJ, and apically up to 8mm; the concavities were wider than deeper; on the mesial surface, the greatest width was (1.05 mm) and the greatest depth was (0.06 mm) both at the CEJ; 5) on the distal surface the greatest width was (0.73 mm) at 6mm apically from the CEJ and the greatest depth was (0.003 mm); the palato-gingival groove was observed in 9.58% of the samples. The mesial surface of the maxillary lateral incisor is the longest. The root concavities on the proximal surfaces are present in 100%. One must get acquainted to the morphological variations of roots to enhance diagnosis and treatment.

Long-term follow-up of severely resorbed maxillary incisors after resolution of an etiologically associated impacted canine

Resorption of maxillary incisor roots because of an impacted canine is a well-recognized phenomenon that occurs in a surprisingly high proportion of patients with impacted canines. In this retrospective study, we studied a sample of patients in whom the resorption was particularly severe. The sample consisted of 11 patients (age, 11.8 +/- 1.2 years) with 20 severely resorbed maxillary incisors. The amount of resorption was measured at the outset (T1), when the impacted canine was distanced from the incisor root area (T2), at the completion of the orthodontic treatment (T3), and at a follow-up appointment at least 1 year posttreatment (T4). A 17.2% increase in the crown/root ratio occurred due to aggressive continued resorption between T1 and T2. The resorption rate reduced to an almost insignificant level, despite continued and often appreciable orthodontic movement of the resorbed teeth from T2 to T3. Patients with impacted canines should be screened for resorption and the impacted tooth treated as soon as possible. The resorption process can be halted and the affected tooth moved orthodontically without further risk of resorption. In the long term, with early treatment, even severely resorbed teeth do not suffer from increased mobility or discoloration and might not require splinting.

Maxillary premolar resorption by canines: three case reports

Three unusual cases of maxillary premolar root resorption are reported. Three teenage patients were referred to the orthodontic department for management of ectopic maxillary canines. Radiographic examination revealed unilateral premolar root resorption in all three patients. This represents an unusual finding. Whereas the prevalence of maxillary lateral incisor root resorption secondary to palatally ectopic canines has been reported, the prevalence of premolar root resorption is unknown. This report discusses the findings in the context of the available literature. The postulated aetiology and the need for early diagnosis are highlighted.

Maxillary incisor root resorption after rapid palatal expansion in Felis catus

Root resorption after rapid palatal expansion (RPE) treatment was found in anchored teeth but has not been studied on non-anchored incisors. This study evaluated root resorption, root tipping, and root proximity of maxillary incisors after RPE treatment. Fourteen cats were divided into treated (n = 10) and untreated (n = 4) groups. The RPE treatment consisted of active, retention, and relapse phases, lasting 25, 60 and 60 d, respectively. Standardized occlusal radiographs were taken to measure tipping and root proximity before and after each treatment phase. Maxillary incisors were analysed histologically by fluorescent microscopy for root resorption. Data was analysed statistically with anova with repeated measures, t-test and Pearson's coefficient of correlation. Root resorption was confined to the first incisors and was 750-fold greater in the treated vs. the control group. Root tipping and root proximity were significantly greater (2.5- and 17-fold, respectively) in the first than in the second maxillary incisor and highly correlated with root resorption (r = -0.927 and 0.723, respectively). This suggests a cause (tipping and root proximity) and effect (root resorption) relationship. Data suggest that first maxillary incisor susceptibility to root resorption during RPE is associated with severe tipping and root proximity.

Maxillary incisor root forms in orthodontic patients in Nairobi, Kenya

To evaluate, radiographically, the root forms of maxillary incisors in a sample of patients seeking orthodontic treatment in Nairobi, Kenya. A retrospective study of maxillary incisor root forms based on periapical radiographs. A private dental clinic in Nairobi, Kenya. The study comprised 393 maxillary incisors in 100 consecutive subjects (51 boys, 49 girls) aged 9-24 years. Intra-oral periapical radiographs of the incisors were evaluated. An index was used to categorise the roots as follows: 0=normal, 1=short, 2=blunt, 3=apical bend, 4=pipette apex. Normal root form was recorded in 60%, short in 12.5%, blunt in 7%, apical bend in 13%, and pippete-apex in 7% of the roots. Sixty nine percent of the pippete-apex roots were in central incisors and 94% of the roots with apical bend were in lateral incisors. Seventy three percent of short roots were in females. Based on evidence from previous studies on risk of root resorption which indicates that pipette and blunt roots are the forms mostly involved in this phenomenon, the present data imply that about 14% of the roots may have been at risk of moderate to severe resorption during fixed orthodontic treatment.

External apical root resorption in Class II malocclusion: a retrospective review of 1- versus 2-phase treatment

External apical root resorption (EARR) is an imperfectly understood problem of orthodontic treatment. The records of 138 children with Class II malocclusion (overjet > 7 mm) participating in a randomized clinical trial of early orthodontic treatment were reviewed. The patients were treated in either 1 phase with fixed appliances only (n = 49) or 2 phases with headgear (n = 49) or bionator (n = 40) followed by fixed appliances. The 3 groups were similar in age, sex, and malocclusion severity at enrollment. The records examined included anamnestic data, clinical examination records, panoramic radiographs before and after fixed appliance therapy, and posttreatment periapical radiographs. All radiographs were reviewed and scored independently by 2 examiners for maxillary incisor root development, morphology, and EARR. Of the 532 incisors scored, 11% of central and 14% of lateral incisors demonstrated moderate to severe (>2 mm) EARR. The proportion of incisors with moderate to severe EARR was slightly greater in the 1-phase treatment group. There was no difference in the incidence of EARR between teeth that had had trauma and those that had not, and there was only a slight increase in frequency of root resorption in teeth with unusual root morphology. Significant associations exist among EARR, the magnitude of overjet reduction, and the time spent wearing fixed appliances. However, not all incisors in a child respond in the same way, so other variables must play a role in determining the root response to orthodontic forces.

Effect of endodontic sealers on dowels luted with resin cement

This study evaluated the retention of prefabricated parallel-sided dowels luted with resin cement in extracted teeth that were obturated with gutta percha using a eugenol sealer or a calcium hydroxide sealer. Extracted maxillary incisor roots (N = 51) were instrumented to simulate conventional root canal therapy and divided into 3 groups (n = 17). One group was not obturated. Second and third groups were obturated with gutta percha using a eugenol-containing or calcium hydroxide-containing sealer. Gutta percha was removed using a heated plugger, and dowel spaces were prepared to a 7 mm depth. Dowel space walls were acid etched and primed, and prefabricated stainless steel dowels were luted using resin cement. After 24 hours, the load required to dislodge each dowel along a path parallel to its long axis was measured and recorded. A one-way analysis of variance (alpha = 0.05) was performed to identify differences in the means among groups. The incidence of failure within the cement or at the dentin-cement interface was also recorded. No statistically significant difference was found among the control (159.9 +/- 96.3 N), eugenol sealer (153.1 +/- 77.3 N), and calcium hydroxide sealer (192.0 +/- 89.3 N) groups. Nearly all specimens displayed adhesive failure at the dentin-resin cement interface. Conventional endodontic obturation using a eugenol-containing or a calcium hydroxide-containing endodontic sealer did not affect retention of prefabricated stainless steel dowels luted with resin cement.

Maxillary incisor root resorption in relation to the ectopic canine: a review of 26 patients.

A retrospective study of 26 patients with maxillary incisor root resorption relating to the presence of an ectopic canine was undertaken from case records. The group consisted of nine male and 17 female patients with a mean age of 12.5 years. There was a total of 35 resorbed teeth, 26 lateral and nine central incisors, and these were related to 32 ectopic canines. The resorption tended to be extensive, 30 teeth had pulpal involvement. In two-thirds of cases the pattern of resorption involved both apical and middle thirds of the root. Despite the extensive nature of the involvement there were few clinical signs and symptoms reported by patients. 43.8 per cent of canines were lying palatal to the arch, 18.7 per cent were in the line of the arch and 37.5 per cent were buccal. Significantly 15.6 per cent were buccal and erupted. The path of canine eruption was mesio-horizontal in 21 cases. No relationship could be found between resorption and the retention or loss of the deciduous canine. The canine root formation was virtually complete in 31 of the involved canines. The study indicated that the problem is often diagnosed late both in relation to the patient's age and the extent of resorption present. It is suggested that the problem may be underestimated by dental practitioners.

Maxillary incisor crown-root relationships in different Angle malocclusions

The long axis of the maxillary incisor root is not always identical to that of the crown. Instead, there is appreciable variation in the crown-root angle, generally with the crown torqued lingual to the root axis. In orthodontic cases assessed before and at the end of full-banded treatment, the crown-root angle was significantly deflected in the Class III molar relationship series, notably so in moderate to severe cases where the maxillary incisors are constrained lingual to the lower arcade. Apical root resorption was not significantly associated with the crown-root angle before or after comprehensive orthodontics. Cephalometric predictors of the amount of deflection of the crown-to-root axis were localized to intertooth relationships (overjet, interincisal angle). It is proposed that the large collum angles in Class III cases develop during tooth eruption when the maxillary incisors are trapped within the lower arch; this torques the crown of the maxillary incisor but leaves the unmineralized portion of the root free to develop as if the crown were still in its prior, more procumbent orientation.

Periapical tissue responses to dentin and vitreous carbon plugs in apical perforations of dogs' teeth.

Abstract Apical perforations were made in 25 roots of mandibular premolars and maxillary incisors of 2 adult Labrador dogs. Autogenic dentin chips or vitreous carbon powder were condensed to form a 2 mm apical plug in each of 16 canals. The coronal segments of the canals were filled with gutta percha and Grossman root canal sealer by the lateral condensation technique. Using the same obturation technique, the remaining 9 canals were HI led with gutta percha and Grossman root canal sealer 2 mm short of the radiographic apices with no apical plugs. Apical bridge formation and periapical inflammation were compared in 3 groups.

Healing of periodontal connective tissues following surgical wounding and application of citric acid in dogs.

Topical application of citric acid to a root surface which has been scaled and root planed results in exposure of collagen fibrils of the dentin matrix. The purpose of this study was to examine the healing of gingival connective tissue adjacent to a root planed and subsequently acid conditioned root surface and to determine whether the exposure of dentin or cementum matrix collagen would facilitate the reestablishment of an attachment between the healing connective tissue and the root surface. Full thickness flaps were raised and labial alveolar bone removed over maxillary incisor roots of seven Labrador retrievers. The exposed root surface was planed before etching with citric acid (pH 1) for 3 min. The flap was then repositioned at its original level. Block sections were obtained after 7, 14, 21 and 42 days and the interface between the root surface and the healing wound tissue studied by light and electron microscopy. Compared to conventional flap surgery in the same animals, application of citric acid to the instrumented root surface resulted in an improved rate of connective tissue healing as well as a rapid and consistent reestablishment of connective tissue attachment through extensive interdigitation of new and old collagen fibrils at the tooth‐gingiva interface. Subsequent reinforcement of the established connective tissue attachment included recalcification of the acid‐affected dentin and deposition of new cementum.