Root Trunk Research Articles

Root Trunk Concavities as a Risk Factor for Regenerative Procedures of Class II Furcation Lesions in Humans

The purpose of this study was to evaluate the influence of root trunk concavities on guided tissue regeneration in humans and to determine if a modification in membrane design could improve the results. Ten patients who provided 10 pairs of similar Class II furcation defects were recruited for the study. Each defect was randomly assigned to treatment with either a normal expanded polytetrafluoroethylene (ePTFE) membrane (NM) or a modified ePTFE membrane (MM). The MM were made by removing the collar from an NM, cutting it into 2 mm segments, and suturing each of the segments to the collar of each MM. Following basic therapy, baseline clinical measurements were recorded using an acrylic stent, including probing depth (PD) and clinical attachment level (CAL). Full flaps were elevated, the defects were carefully debrided, and the root surfaces were decontaminated with manual and ultrasonic instruments. Hard tissue measurements were performed during surgery to determine vertical (VD) and horizontal defect (HD) depths. Then, NM and MM were sutured to their corresponding tooth and the flaps sutured. Membranes remained in position for 6 weeks. After 1 year, all sites were re-entered and soft and hard tissue measurements were recorded. After 1 year, there were no statistically significant differences (Mann-Whitney test) between NM and MM groups in percentages of PD reduction (P= 0.27), CAL change (P= 0.26), or VD resolution (P = 0.13). However, percentage of HD resolution (NM: 24.3+/-11.8; MM: 44.8+/-16.0) was significantly different between groups (P= 0.008). The modified membranes resulted in greater horizontal resolution of Class II furcation defects. The collars of the membranes should be modified to improve results when root trunk concavities are present.

A stilbene dimer, andalasin B, from the root trunk of Morus macroura

A new stilbene dimer, andalasin B, was isolated from the root trunk of Morus macroura Miq., together with three known compounds, andalasin A, lunularin, oxyresveratrol, and β-resorcylaldehyde.

Radiographic parameters as prognostic indicators for healing of class II furcation defects.

To evaluate radiographic measurements for use as prognostic indicators for healing of class II furcation defects following regenerative therapy. In 17 patients (eight females), 33 class II furcation defects (mandibular buccal (n=10) and lingual (n=12), and maxillary buccal (n=11)) were treated using the barrier membrane technique. Twenty-six furcations were treated using a bioabsorbable membrane, while a nonresorbable membrane was used to treat the remaining seven furcation defects. Clinical parameters and standardized radiographs were obtained before as well as 6 and 24 months after therapy. All radiographs were digitized and evaluated by an examiner blinded to the clinical data. The following distances were measured: cemento-enamel junction line (CEJ-line) to alveolar crest (AC) at the furcation site (AC-CEJ line), CEJ-line to the furcation fornix (Fx-CEJ line), width of the furcation at the level of the AC (FW) as well as the distance from Fx to a straight line between the AC mesial and distal of the tooth (Fx-AC line). Statistically significant (p<0.001) horizontal attachment gains could be observed 6 and 24 months after therapy (6 months: 1.49+/-0.85 mm; 24 months: 1.14+/-0.91 mm). However, a small but statistically significant (p=0.031) attachment loss of 0.35 mm was observed between the 6 and 24 months examination. Multilevel regression analyses identified baseline probing depth (p=0.0017) and 3 of the radiographic distances as prognostic factors: Fx-CEJ line (p=0.014), FW (p=0.0535), Fx-AC line (p=0.0827). The analysis of presurgical radiographs may yield information on the success of the regenerative therapy of buccal and lingual class II furcation defects. A long root trunk, a wide furcation entrance and an Fx coronal to the AC have negative influences on the success of therapy. Further, a deep probing depth at the furcation site at baseline increases the likelihood for more favourable horizontal attachment gain in furcations.

Surgical Extraction of the Maxillary Fourth Premolar Tooth in the Dog

Dental extraction is indicated for end-stage periodontal disease, fractured teeth with exposed pulp (when endodontic treatment is not possible), retained deciduous teeth, crowded or malpositioned teeth, and in other select cases. Chewing hard objects is the most common etiology for fracture of the maxillary fourth premolar tooth in dogs. Extraction of the maxillary fourth premolar tooth is a surgical procedure. The extraction procedure involves: creating a mucoperiosteal flap, removing buccal alveolar bone, and sectioning the tooth to facilitate elevation of its three separate roots. Crown sectioning is generally recommended for multirooted teeth in order to decrease the difficulty of extraction. Sectioning should be performed at the furcation(s) to transform a large multirooted tooth into multiple, single crown-root segments that are more easily extracted. In the method described here, sectioning of the mesial root trunk is preceded by amputation of the mesial cusp to allow for more accurate sectioning at the mesial furcation. Removal of buccal alveolar bone, crown sectioning, and controlled elevation of tooth crown-root segments minimizes operative complications including root fragmentation, infraorbital artery and nerve injury, penetration of the nasal cavity, and ocular trauma. Other procedural recommendations include alveoloplasty performed with a #4 round bur and a high-speed handpiece to remove any rough or sharp bony projections at the extraction site. Alveoloplasty is complete when digital palpation of the extraction site indicates no sharp projections Finally, the alveolus is irrigated with 0.12 % chlorhexidine solution to decrease bacterial contamination and remove any debris. Primary wound apposition is recommended to reduce postoperative hemorrhage and promote early wound healing. Tension-free wound closure may be facilitated by incising the periosteal attachment in order to mobilize the mucoperiosteal flap. Surgical extraction of the maxillary fourth premolar, including the mesial cusp amputation technique, is described step-by-step.

Biometric study of the width, length and depth of the root trunk groove of human lower second molars.

One hundred human lower second molars, 51 from the left side and 49 from the right side, extracted due to their poor clinical and radiographic conditions were utilized in this study. Using a Contracer apparatus, the profiles of the buccal and lingual root surfaces of these teeth were traced on a millimeter-scaled paper. The profiles were registered from the cementoenamel junction (CEJ), millimeter by millimeter, up to the entrance of the furcation. The width, length and depth of the root trunk groove, as well as the length of the root trunk, were studied. After statistical analysis (p < 0.05) it was possible to conclude that: a) the mean width of the root trunk groove on the buccal surface was 3.6 mm and, on the lingual surface, 3.3 mm; b) the mean depth of the root trunk groove on the buccal surface was 0.88 mm and, on the lingual surface, 0.77 mm; c) the mean length of the root trunk groove on the buccal surface was 2.93 mm and, on the lingual surface, 3.61 mm. The mean length of the root trunk on the buccal surface was 3.09 mm and, on the lingual surface, 3.91 mm (p < 0.025). There was a coincidence between the length of the root trunk and that of its groove in 90.2% of the buccal surfaces of the samples from the left side, and in 77.5% of the samples from the right side; on the lingual surface, the coincidence occurred in 77.5% of the teeth from the left side, and on 88.3% of the teeth from the right side. This work revealed that there is a concavity on the root trunk region of the lower second molar, whose depth and width were greater on the buccal surface and whose length was greater on the lingual surface. The depth of the root trunk groove increased in the apical direction, with maximum depth in the last millimeter of the root trunk. The root trunk was longer on the lingual surface than it was on the buccal surface.

Root trunk concavities as a risk factor for regenerative procedures of class II furcation lesions in dogs.

The purpose of this study was to evaluate the influence of root trunk concavities on guided tissue regeneration. The second, third, and fourth mandibular bicuspids of 4 healthy mongrel dogs were used. Full flaps were elevated and furcation lesions (5 mm in height and 2 mm in depth) were surgically created. One mm deep concavities were prepared on the root trunks and part of the crown of all teeth. The second bicuspids remained as controls (C); the left third and fourth bicuspids received normal expanded polytetrafluoroethylene (ePTFE) membranes (NM) and the right bicuspids received modified ePTFE membranes (MM). The MM were made by removing the collar from an NM, cutting it into 2 mm segments, and suturing each of the segments to the collar of each MM. Normal and modified membranes were sutured to their corresponding teeth and the flaps sutured. After the healing period, the mandibles were removed and the teeth processed for histomorphometry. The results showed that the junctional epithelium measured a mean of 0.71 mm for C, 0.64 mm for NM, and 0.14 mm for MM. The differences between C and MM and between NM and MM were both statistically significant at the 5% level (Kruskal-Wallis test). Mean bone height measurements for the buccal surfaces from the furcation roofs were 2.79 mm for C, 2.60 mm for NM, and 1.06 mm for MM and for the mid-portion 1.10 mm for C, 1.23 mm for NM, and 0.30 mm for MM. Differences were statistically significant at the 1% level between C and MM and between NM and MM for the buccal measurements, and at the 5% level between NM and MM for the mid-portion measurements. Root trunk concavities are important risk factors for regenerative procedures. The collars of the membranes should be modified to improve results when concavities are present.

Mandibular and maxillary furcation tunnel preparations – literature review and a case report

The objective of this literature review and subsequent case report is to discuss and illustrate the tunnel preparation procedure as a treatment alternative for furcation-involved molars. Furcation tunnel preparation, i.e., the creation of access for plaque control between periodontally diseased roots, has not been discussed in the literature as comprehensively as root resective therapy, though success rates appear to fall within the same range. A short root trunk and a wide furcation entrance diameter are prerequisites for the indication of the tunnel preparation procedure. Although accessory canals in the furcation area are frequent findings on extracted teeth, endodontic complications have not been reported to be major complications after tunnel preparation. Caries developed at tunneled teeth even under proper maintenance, but did not necessarily lead to the loss of an affected tooth. In the case presented to illustrate the indication for the tunnel preparation procedure, periodontal disease was almost entirely restricted to the furcation sites of molar teeth. Affected teeth were either extracted or left intact and subjected to tunneling procedures. Periodontal health could be established and maintained at both single and double tunnels over a period of 2 years of periodontal supportive therapy.

The characteristics of Korean multi-rooted teeth root trunk extracted by periodontal disease

The characteristics of Korean multi-rooted teeth root trunk extracted by periodontal disease

Mandibular and maxillary furcation tunnel preparations - literature review and a case report

The objective of this literature review and subsequent case report is to discuss and illustrate the tunnel preparation procedure as a treatment alternative for furcation-involved molars.Furcation tunnel preparation, i.e., the creation of access for plaque control between periodontally diseased roots, has not been discussed in the literature as comprehensively as root resective therapy, though success rates appear to fall within the same range. A short root trunk and a wide furcation entrance diameter are prerequisites for the indication of the tunnel preparation procedure. Although accessory canals in the furcation area are frequent findings on extracted teeth, endodontic complications have not been reported to be major complications after tunnel preparation. Caries developed at tunneled teeth even under proper maintenance, but did not necessarily lead to the loss of an affected tooth.In the case presented to illustrate the indication for the tunnel preparation procedure, periodontal disease was almost entirely restricted to the furcation sites of molar teeth. Affected teeth were either extracted or left intact and subjected to tunneling procedures. Periodontal health could be established and maintained at both single and double tunnels over a period of 2 years of periodontal supportive therapy.

A study on the imaging of complex furcation forms in upper and lower molars

The form of the molar roots and their furcated region influence both the pathogenesis of periodontal destruction and therapeutic attempts. Using a specially-constructed measuring device, 359 1st and 2nd molars, both upper and lower, were analysed 3-dimensionally. The parameters measured were horizontal furcation concavity, height of root trunk, degree of root taper, the distance between the root prominences adjacent to the furcation entrances and the angle of root separation. The mean horizontal furcation concavity in lower molars was 0.5 mm at a distance of 1 mm apical to the cemento-enamel-junction (CEJ) and 3 mm at the distance of 4 mm apical to the CEJ. The angle of root separation was between 16 degrees (lower jaw molars lingual) and 29 degrees (upper jaw molars distal). The vertical distance from root separation to CEJ averaged 3.3 mm in lower jaw molars and 4.8 mm in upper jaw molars. Our findings underline the variability of furcation morphology.

A four-rooted quadrangular maxillary molar

The endodontic treatment of a maxillary molar with an aberrant root morphology can be diagnostically and technically challenging. This case report is presented to illustrate and describe the endodontic treatment of a four-rooted maxillary molar with a quadrangular root trunk morphology.

Patterns of Structural Failures in Urban Trees: Coast Live Oak (Quercus Agrifolia)

Data from the California Tree Failure Report Program (CTFRP) were analyzed to develop a profile of the structural failure characteristics for coast live oak (Quercus agrifolia). The most common pattern of structural failure for coast live oak reported in the CTFRP is a root or low trunk failure of a naturally occurring tree growing in a residential site. Decay, site grade changes, and low wind speeds are significantly more frequently associated with coast live oak failures than with other hardwoods, conifers, or eucalyptus. Decay of roots and lower trunk was a major contributing factor to failure of coast live oak (83%). Saturated soil conditions associated with root failure were also more frequent for coast live oak than for other species groups. Careful attention to controlling excess soil moisture, avoiding or correcting grade change and compaction, and monitoring decay are essential to maintain the health of coast live oak.

デンタルＸ‐Ｐによる補綴学的診断

The purpose of this study was to investigate the problem of prosthetic diagnosis using periapical dental radiographs for crown and bridge. In general, periapical dental radiographs were on the following.1. The form of pulp cavity.2. The length ratio of crown to root.3. The form of root trunk.4. The resorption of root and bone.5. The dental caries and the root fracture.6. The structure of periodontal tissue (the space of periodontal membrane, the alveolar border, the lamina dura and the spongy substance of alveolar bone).The radiographic findings are useful for periodontic and endodontic diagnosis. More useful and functional information must be obtained for prosthetic diagnosis. Thus, the suggested plans are as follows:1. The crown and bridge made by prosthodontist with a 5-year guarantee.2. The oral radiologist should administer and manage all periapical dental radiographs.3. To investigate viewing radiographs from a functional perspective.4. Practice of prosthetic treatment with team-approach.Two cases were reported. One was a destruction case of periodontal tissue by ITI implant. The other was a reconstruction case of periodontal tissue by the transplantation of mandibular molar following iliac cancellous bone graft.

Anatomic characteristics of the furcation and root surfaces of molar teeth and their significance in the clinical management of marginal periodontitis.

Treatment of periodontitis which involves the furcation area of molar teeth has always been a challenge. Sixty extracted human molar teeth were used for an anatomic study to clarify the possible morphologic factors which may affect the diagnosis, prognosis, and clinical management of periodontally involved teeth. Teeth were embedded in methylmethacrylate and cut in 70 microm cross sections from the cementoenamel junction to the apex. Cervical enamel projection, root and root trunk lengths, root proximities as well as depths of root concavities coronally, apically, and at the furcation roof were measured. Cervical enamel projections were observed in 30% of the teeth examined. The shortest root trunk was found at the buccal aspect of mandibular first molars, permitting furcation involvement at early stages of periodontal disease. The most apically located furcation was found at the distal site of maxillary first molars. Furcation roofs showed severe concavities and complex cementum morphology. Teeth exhibiting cervical enamel projection were found to have deeper root concavities compared to teeth without cervical enamel projection and mesial roots of mandibular molars possessed greater furcal concavities than distal roots. The presence of root concavities complicates the diagnosis of furcation involvement and restricts access of periodontal instruments, resulting in incomplete treatment. Furcation anatomy may also influence the long-term prognosis of the teeth by favoring the retention of bacterial deposits and making oral hygiene procedures almost impossible. The present study shows that knowledge of a tooth's unique anatomic characteristics is a prerequisite for effective periodontal therapy.

Types and dimensions of root trunk correlating with diagnosis of molar furcation involvements.

The objective of the present study was to investigate the possible correlation of dimension, location, prevalence, and types of root trunk with molar furcation involvement (FI). The samples used in the study include 166 maxillary molars (70 1st and 96 2nd molars) and 200 mandibular molars (103 1st and 97 2nd molars). The dimensions of the root trunks and root lengths were measured with an electric caliper and their means and standard deviations calculated. The types of root trunks were identified by the ratio of root trunk dimension to root length and classified as types A, B, and C. The results may be summarized as follows. (1) Short-root trunks were more commonly found buccally, whereas long-root trunks were more commonly found mesially, in both maxillary molars. (2) Short-root trunks were most commonly found buccally, whereas long-root trunks were more commonly found lingually in both mandibular molars. (3) Long-root trunks were more commonly found on the 2nd molars than on the 1st molars. (4) Long-root trunks were associated with short root length. (5) There is a strong correlation between vertical length and type of root trunk and FI. The findings of the study indicated that an awareness of root trunk type together with horizontal and vertical attachment levels in molar FI may be helpful in the prognosis, diagnosis, and treatment of molar FI.

Clinical significance of furcation anatomy of the maxillary first premolar: a biometric study on extracted teeth.

Multirooted teeth in which chronic periodontitis has progressed to involve the furcation present special problems in treatment. The apical placement of furcation, narrow furcation entrance, concavities on the root surface, and the undesirable root configuration make instrumentation and plaque control difficult. Furcation involvement, when present in maxillary first premolars in particular, presents a poor prognosis as the furcation opens mesiodistally. This study on 100 extracted maxillary first premolars is an attempt to determine the frequency of bifurcation, the proximity of bifurcation to cemento-enamel junction, the depth of concavities on the root trunk and the furcal aspect of root, the diameter of furcation entrance, and the extent of root divergence.

The morphology of root fusion in Chinese adults (I). Grades, types, location and distribution

The purpose of the present study was to investigate the morphology, extent, and distribution of root fusions in 1st and 2nd permanent molars in a Chinese population. The sample consisted of 158 maxillary and 151 mandibular extracted 1st and 2nd molars. Root fusion in molars was assessed by direct viewing and measuring the length of the root and root trunk with stereoscopic microscopy. Root fusion was graded by the extent of fusion and the number of affected surfaces. The main results were as follows: (1) the majority of root fusions affected upper and lower 2nd molars (39.7% and 28.1%, respectively); (2) the prevalence of maxillary roots with 1, 2 and 3 fusions was 55.2%, 31.3% and 13.4% respectively, and most of the root fusions affected the maxillary 2nd molars (65.7%); (3) the majority of mandibular root fusions affected the 2nd molars (89.2%), and were of grade III (48.7%); (4) in order of decreased prevalence, the grades of root fusion in 2nd molars were grades III, II and I; whereas in 1st molars they were grades I, II and III; (5) there were 44 (41.5%) and 19 (51.4%) complete root fusions (grade III) among 106 fused roots in maxillary molars and 37 fused roots in mandibular molars, respectively.

Topographical characteristics of root trunk length related to guided tissue regeneration.

Thirty-seven molars with 94 furcations were selected for a topographical study of root trunks to clarify the possible factors which may affect the clinical application of guided tissue regeneration technique. A pre-determined plane was marked on the root trunk of each tooth 1 or 2 mm below the cemento-enamel junction (CEJ). The plane followed the presumed position of the occlusal border of the Teflon membrane. Cross sectioning of the root was then performed following the plane, and the width of the gap between the membrane and root surface was measured with the aid of a stereomicroscope. The results revealed, within the limited samples of this study, 94% of the furcations possessed variant depth of developmental concavities on the root trunks. These superficial irregularities at the entrances of furcations may prevent complete adaptation of the coronal microstructure of the Teflon membrane along their root surfaces. The width of the gaps between root surfaces and membranes ranged from 0.000 mm to 2.250 mm for all tooth samples. The study implied that the subgingival application of guided tissue membranes 1 to 2 mm below CEJ cannot ensure complete adaptation of furcation defects with their coronal microstructures in the majority of molars.

Potential attachment area of the first mandibular molar in dogs

Summary Tooth root and root trunk surface area measurements were taken from 20 first mandibular molar (M1) teeth obtained randomly from canine cadaver specimens. The mean root surface area for all teeth was 497.1 ± 116.2 mm2. The cumulative surface areas of the mesial (mr) and distal (dr) roots were 251.4 ± 70.2 mm2 and 211.7 ± 51.9 mm2, respectively. The root trunk surface area was 34.0 ± 21.4 mm2. Surface area measurements for individual roots and the root trunk were significantly different. Cumulative individual root surface area (mr + dr) was 93.2% of total root surface area. The mr surface area contributed most to total root surface area (50.6%) and cumulative individual root surface area (54.3%). The mean distance from the beginning of the root trunk to the furcation was 2.1 mm. On the basis of the linear variation of the percentage of root surface area of the M1, 44.6% of the total root surface area was 3 to 7 mm apical to the most coronal aspect of the cementoenamel junction. The mr was heart-shaped, compared with the more cylindrical shape of the dr.

Potential attachment area of the fourth maxillary premolar in dogs

SUMMARY Tooth root and root trunk surface area measurements were made on 20 permanent fourth maxillary premolar (P4) teeth randomly harvested from canine cadaver specimens. Mean root surface area for all 20 teeth was 562.8 ± 124.9 mm2. Cumulative surface areas of the mesiopalatal, mesiobuccal, and distal roots were 113.8 ± 29.0 mm2, 138.5 ± 34.6 mm2, and 180.8 ± 39.9 mm2, respectively. The mesial root trunk and distal root trunk surface areas were 60.0 ± 17.5 mm2 and 72.1 ± 33.2 mm2, respectively. There was not a significant difference between the root surface area of the mesial root trunk and distal root trunk; however, all other root surface area measurements were significantly different (P &lt; 0.01). Cumulative individual root surface area (distal root + mesiobuccal root + mesiopalatal root) was 76% of total root surface area. The distal root surface area contributed most to total root surface area (32.1%) and cumulative individual root surface area (41.7%). Observation of the linear variation of percentage of root surface area revealed 40.8% of the total root surface area to be in the portion located between 5 and 9 mm apical to the most coronal aspect of the cementoenamel junction. The mesiobuccal root and distal root were cylindrical compared with the flattened, concave shape of the mesiopalatal root.