Furcation Area Research Articles

A methodology to standardize the evaluation of root canal instrumentation using cone beam computed tomography

The evaluation of root canal instrumentation is important to observe the action of endodontic instruments in the root canal walls. Aim: This study introduces a method to standardize the acquisition of images before and after preparing root canals by using cone-beam computed tomography (CBCT). Methods: Sixteen mandibular molars were included in acrylic resin blocks. Samples were inserted in a stable wood box, which was filled with plaster and served as a guide to reinsert the samples. The apparatus was used for the CBCT examination before and after cervical flaring of root canals. The software IcatVision® was used to equalize the images before and after instrumentation with two computers operating at the same time. The measurements between root canal center and the furcation area were determined. The statistical analysis was performed using the t-test for paired samples (a=0.05). Results: The values for dentin thickness in the risk zone before and after root canal flaring with Gates-Gliden drills were 1.096 (± 0.27) mm and 0.742 (± 0.24) (p<0.01), respectively. Conclusions: The proposed method assures the same positioning of the samples before and after root canal preparation. It is extremely important, as any mesiodistal or buccolingual movement can produce a different topogram for comparison procedures.

Clinical and Radiographic Evaluation of the Effect of Bovine-derived Hydroxyapatite (Bio-Oss®) and A Synthetic HA/β-TCP (Osteon®) in the Treatment of Class II Furcation Defects in Mandibular Molars

Background and aims. There are some studies comparing bone replacement grafts. The aim of this study was clinical evaluation of the effect of Osteon® (as a new bone material) and Bio-Oss® (Bovine-derived hydroxyapatite) in the treatment of mandibular molar class II furcation defects in humans. Materials and methods. Eleven patients (10 females and 1 male, age range of 27-59 years ; mean age of 45.5±11.8 years) who had at least 22 mandibular class II buccal or lingual furcation defects were treated either with Osteon (as the case group) or Bio-Oss (as the control group). Each defect was randomly assigned to either the case group or the control group. Clinical parameters and the soft tissue and hard tissue measurements, including plaque index (PI), gingival index (GI), gingival recession of furcation area (GR), pocket depth (PD), clinical attachment level (CAL), horizontal defect depth (HDD), vertical defect depth (VDD) were recorded at baseline and six months after surgery. Data were analyzed using t-test or Wilcoxon's test. Results. Similar healing results were observed for both treatments. The results showed significant probing depth reduction (case group: 0.77 mm and control group: 0.84 mm) and HDD reduction (case group: 0.51 mm and control group: 0.8 mm) and PI reduction. There was not statistically significant difference between the groups in all soft and hard tissue parameters. Conclusion. The results of this study showed that the effect of using Osteon as a bone graft material is the same as that of Bio-Oss in the treatment of mandibular class II furcation defects.

Comparing Canal Transportation and Centering Ability of EndoSequence and Vortex Rotary Files by Using Micro–Computed Tomography

IntroductionEndoSequence and Vortex are 2 recently developed rotary file systems that are made with traditional nickel-titanium (NiTi) and M-Wire technology, respectively. Previous studies have demonstrated better fatigue resistance of M-Wire rotary files compared with the conventional NiTi file. However, no study has compared the effects of M-Wire and conventional NiTi on transportation and centering ability. Hence, the aim of this study was to evaluate the transportation and centering ability of EndoSequence and Vortex files in mesial roots of mandibular molars by using micro–computed tomography imaging. MethodsSixteen extracted mandibular molars with mesiobuccal and mesiolingual canals with separate foramina were used. Preinstrumentation scans of all teeth were taken, and the teeth were divided into 2 groups. In group 1, the mesiobuccal canals were instrumented with Vortex files and the mesiolingual canals with EndoSequence files. In group 2, the mesiobuccal canals were instrumented with EndoSequence files and the mesiolingual canals with Vortex files. Two file sizes were compared, 30/.04 and 40/.04. Postinstrumentation scans were performed, and the 2 scans were compared to determine centering ability and transportation. ResultsThe amount of transportation at 1, 3, and 5 mm was similar for both file types in both file sizes. Transportation toward the furcation area at 7 mm was greater with the 30/.04 Endosequence files compared with the Vortex 30/.04 files (P < .05), but there was no difference in size 40/.04 files. ConclusionsOverall, our study does not support the use of one rotary file system over the other (Vortex or EndoSequence) when comparing transportation and centering ability.

Multiple regenerative techniques for class II furcation defect

AbstractRegeneration of the periodontium is a major goal in the treatment of teeth affected by periodontitis. Periodontal regeneration is quite challenging, especially when it is in the furcation area. There are several techniques used alone or in combination, considered to achieve periodontal regeneration, including bone grafts or substitutes, guided tissue regeneration, root surface modification, and biological mediators. Many factors may account for variability in the response to regenerative therapy in class II furcation. This case report describes the management of a buccal class II furcation defect, with the help of surgical intervention, including the guided tissue regeneration (GTR) membrane and bone graft materials. This combined treatment resulted in a healthy periodontium, with radiographic evidence of alveolar bone gain. This case report demonstrates that proper diagnosis, followed by removal of the etiological factors and utilizing combined treatment modalities, restored health and function of the tooth with severe attachment loss, at the 18-month follow-up.

Treatment of experimental periodontitis in rats using repeated adjunctive antimicrobial photodynamic therapy

The aim of this study was to histologically and histometrically evaluate the influence of repeated adjunctive antimicrobial photodynamic therapy (aPDT) on bone loss (BL) in furcation areas in rats. Periodontitis was induced by placing a ligature around the mandibular molar in 75 rats. The animals were divided into five groups: the SS group was treated with saline solution (SS); the SRP group received scaling and root planing (SRP); the aPDT1 group received SRP as well as toluidine blue (TBO) and low-level laser therapy (LLLT; InGaAlP, 660 nm; 4.94 J/cm(2)/point) postoperatively at 0 h; the aPDT2 group received SRP as well as TBO and LLLT postoperatively at 0, 24, 28, and 72 h; and the aPDT3 group received SRP, TBO, and LLLT postoperatively at 0, 48, 96, and 144 h. The area of BL in the furcation region of the molar was histometrically analyzed. Data were analyzed statistically (P < 0.05). Animals treated with a single episode of aPDT showed less BL at days 7 and 30 than those who received only SRP treatment. No significant differences were found among the aPDT groups (P > 0.05). Repeated aPDT did not improve BL reduction when compared to a single episode of aPDT.

Morphometric study of the root anatomy in furcation area of mandibular first molars

Furcation involvement in periodontal disease has been a challenge for the dentist.ObjectiveThe aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. Material and MethodsDigital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). ResultsMean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20º and 37.78±13.18º for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). ConclusionsIn conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions.

Management of pulpal floor perforation and grade II Furcation involvement using mineral trioxide aggregate and platelet rich fibrin: A clinical report

To report the management of an iatrogenic perforation of pulpal floor in the furcation of mandibular first molar, using Mineral Trioxide Aggregate (MTA) and platelet rich fibrin (PRF). Unpredictable endodontic root/pulp chamber floor perforations resulting in unacceptable high rate of clinical failure has now been a lesser threat with the advent of new technologies and biocompatible materials that utilize the applications of basic research along with tissue engineering concept in clinical practice. Present case report illustrates the use of MTA and platelet rich fibrin (PRF) for the repair of the perforation defect and regeneration of the lost periodontium in furcation area. Although, histologic events and reaction of MTA with PRF is not studied so far, however, the autologous and biocompatible nature of the components used for present treatment modalities seems to be beneficial for the long term clinical results obtained in our case.

Dens Evaginatus in Proximal Surface of Mandibular Premolar: A Rare Presentation

Dens evaginatus is a developmental anomaly that is characterized by occurrence of an extra cusp-like structure projecting from the crown portion of the tooth. Unusual extension of enamel has been found in posterior teeth as enamel pearl or as cervical enamel extensions from the cementoenamel junction or at the furcation areas. We hitherto report a case of extra enamel formation from the proximal surface of the crown in a mandibular premolar, a finding that has previously not been reported.

Effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars

The aim of this study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of mandibular molars, using sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), individually and in alternation. The occlusal surface and the roots of 20 non-carious extracted human permanent mandibular molars were cut transversally and discarded. The tooth blocks were embedded in acrylic resin and randomly assigned to 4 groups (n=5) according to the irrigating regimens: 1% NaOCl solution, 17% EDTA solution, 1% NaOCl and 17% EDTA and distilled water (control). Knoop microhardness of dentin at the furcation area was evaluated. Data were analyzed using one-way ANOVA and Tukey's multiple comparison tests (α=0.05). The results of this study indicated that all irrigation solutions, except for distilled water (control), decreased dentin microhardness. EDTA did not show a significant difference with NaOCl/EDTA (p>0.05), but showed a significant difference with NaOCl (p<0.01). EDTA and NaOCl/EDTA showed a maximum decrease in microhardness. The 17% EDTA solution, either alone or in combination with 1% NaOCl reduced significantly dentin microhardness at the furcation area of mandibular molars.

Changes in periodontium after extraction of a periodontally-involved tooth in rats

PurposeRecent interest has focused on intentional replantation to restore an original tooth. Some studies have shown successful results with intentional replantation for periodontally involved teeth. For long-term success of replantation, a healthy periodontal status of the recipient site is required so that delayed replantation is more suitable for periodontally involved teeth. To reveal the ideal timing for delayed replantation of periodontally involved teeth, the healing process of extraction sockets after extraction of periodontitis-induced teeth in rats was evaluated.MethodsTwenty-eight rats were randomly divided into two groups: a control group (n=8) and test group (n=20). In the test group, periodontitis was induced by a ligature around the cervix of the mandibular first molar of all of the rats. Two weeks later, the mandibular first molars were extracted in all of the animals. The animals were sacrificed on days 0, 3, 7, and 10 after extraction and histological and immunohistochemical analysis was performed.ResultsIn histological analysis of the test group, inflammatory cell infiltrate was found abundantly in the remaining periodontium 3 days after tooth extraction and decreased gradually at later time points. In immunohistochemical analysis of the test group, both interleukin-6 (IL-6) and, tumor necrosis factor-α (TNF-α) were numerous in the furcation area at each postextraction day. IL-6 was stained more heavily between 3 and 7 days after extraction; at day 10 after extraction, little staining was observed. TNF-α staining was more intense at 3 days after extraction and gradually weakened at later points in time.ConclusionsWithin the limits of this study, it takes at least 10 days to resolve periodontal inflammation in rat extraction sockets.

An evaluation of apical microleakage in roots filled withthermoplastic synthetic polymer based root canal fillingmaterial (RealSeal 1 bonded obturation)

Background: This study aimed to evaluate and compare the apical microleakage of roots canal filled with cold lateral condensation of gutta-percha, cold lateral condensation of Resilon, Thermafil and RealSeal1 bonded obturation. Materials and methods: Sixty freshly extracted maxillary first molars with straight palatal roots .Using diamond disc bur with straight hand piece and water coolant the palatal roots of teeth were sectioned perpendicular to the long axis at the furcation area. All roots were prepared with crown-down technique using hand ProTaper system (Sx-F4).The prepared roots randomly divided into 4 groups of fifteen roots each; the groups obturated with different obturation technique. In Group 1 roots obturated with( lateral condensation of gutta-percha), Group 2 was obturated with(lateral condensation of Resilon),group3 was obturated with (Thermafil) while in group4 obturated with( RealSeal 1 bonded obturation).All the samples sealed coronally and stored in normal saline at 37°C for one week ,then all the roots submerged Indian ink for one week. The roots were cleared and the degree of linear dye penetration was measured in millimeter by stereomicroscope under 40X magnification with calibrated scale ocular grid. Results: The results showed that the RealSeal1 bonded obturation leaked apically significantly higher than other test groups, while the group of lateral condensation of gutta-percha exhibited the least value of apical microleakage. Conclusion: The complete hermetic apical seal cannot be created neither with gutta-percha nor with Real Seal 1bonded obturation.

Association between dentin thickness and presence of accessory foramina in human permanent mandibular molars

The roots and periodontal system in human dentition are closely correlated from the early stages of dental formation, maintaining this connection after teeth are established in the oral cavity through the apical foramen or other communications. Aim: Therefore, the aim of this study was to evaluate the correlation between the presence of foramina on the pulp chamber floor surface and in the furcation region and the thickness of dentin in this area. Methods: Forty sound permanent mandibular molars were submitted to scanning electron microscopy (SEM) to determine the presence of foramina on the pulp chamber floor and in the furcation region, and to correlate the presence of foramina with the variation in wall thickness in these regions. Results: The results showed a mean thickness of 2.16 mm for the teeth analyzed and a 25% frequency of foramina on the pulp chamber floor and 92.5% in furcation area, with only 22.5% showing foramina on both sides. The foramina found on both surfaces showed varied diameters and shapes and locations dispersed throughout the area. Conclusions: There was no significant difference between the mean thicknesses of teeth featuring foramina and those without foramina.

Impact of Cannabis Sativa (Marijuana) Smoke on Alveolar Bone Loss: A Histometric Study in Rats

Cannabis sativa (marijuana) can interfere with bone physiopathology because of its effect on osteoblast and osteoclast activity. However, its impact on periodontal tissues is still controversial. The present study evaluates whether marijuana smoke affects bone loss (BL) on ligature-induced periodontitis in rats. Thirty male Wistar rats were used in the study. A ligature was placed around one of the mandible first molars (ligated teeth) of each animal, and they were then randomly assigned to one of two groups: control (n = 15) or marijuana smoke inhalation ([MSI] for 8 minutes per day; n = 15). Urine samples were obtained to detect the presence of tetrahydrocannabinol. After 30 days, the animals were sacrificed and decalcified sections of the furcation area were obtained and evaluated according to the following histometric parameters: bone area (BA), bone density (BD), and BL. Tetrahydrocannabinol was positive in urine samples only for the rats of the MSI group. Non-significant differences were observed for unligated teeth from both groups regarding BL, BA, and BD (P >0.05). However, intragroup analysis showed that all ligated teeth presented BL and a lower BA and BD compared to unligated teeth (P <0.05). The intergroup evaluation of the ligated teeth showed that the MSI group presented higher BL and lower BD (P <0.05) compared to ligated teeth from the control group. Considering the limitations of this animal study, cannabis smoke may impact alveolar bone by increasing BL resulting from ligature-induced periodontitis.

Tunnel preparation for the treatment of furcation area: Case report

Tunnel preparation for the treatment of furcation area: Case report

Summary of: Sealing ability of mineral trioxide aggregate, glass ionomer cement and composite resin when repairing large furcal perforations

Objective To evaluate the sealing ability of different repair materials and the pathway of bacterial penetration after closure of large pulp chamber floor perforations. Materials and methods Perforations were made in the furcation area of extracted human molars and sealed with either mineral trioxide aggregate (MTA), glass ionomer cement or resin composite. The bacterial leakage method was used with Enterococcus faecalis as microbial tracer. The time of leakage (in days) was recorded for each specimen. Statistical analysis of bacterial leakage was performed using the survival analysis and pairwise comparison of groups. A p-value less than 0.05 was considered statistically significant. Leaking specimens were prepared and inspected for the presence of bacteria by a scanning electron microscope (SEM). Results The percentage of leaking samples was significantly higher in resin composite than in the other groups and the negative control group (p <0.05). SEM inspection revealed the presence of bacteria in all leaking specimens. Bacteria were observed along the filling-dentine interface as well as in dentinal tubules at some distance from the filling. Conclusions The resin composite material leaked significantly more than the MTA and glass ionomer cements when used to repair large furcation perforations. Bacteria could penetrate into dentine even at a distance from the perforation filling.

Sealing ability of mineral trioxide aggregate, glass ionomer cement and composite resin when repairing large furcal perforations

To evaluate the sealing ability of different repair materials and the pathway of bacterial penetration after closure of large pulp chamber floor perforations. Perforations were made in the furcation area of extracted human molars and sealed with either mineral trioxide aggregate (MTA), glass ionomer cement or resin composite. The bacterial leakage method was used with Enterococcus faecalis as microbial tracer. The time of leakage (in days) was recorded for each specimen. Statistical analysis of bacterial leakage was performed using the survival analysis and pairwise comparison of groups. A p-value less than 0.05 was considered statistically significant. Leaking specimens were prepared and inspected for the presence of bacteria by a scanning electron microscope (SEM). The percentage of leaking samples was significantly higher in resin composite than in the other groups and the negative control group (p<0.05). SEM inspection revealed the presence of bacteria in all leaking specimens. Bacteria were observed along the filling-dentine interface as well as in dentinal tubules at some distance from the filling. The resin composite material leaked significantly more than the MTA and glass ionomer cements when used to repair large furcation perforations. Bacteria could penetrate into dentine even at a distance from the perforation filling.

Root Resorption in the Furcation Area: A Differential Diagnostic Consideration

This report describes the case of a 51-year-old female who was referred to a periodontist with a tentative diagnosis of complicated furcation defect in the facial aspect of the second permanent molar in the mandibular right quadrant. The clinical examination revealed an asymptomatic tooth without evidence of abnormal attrition, caries, or periodontitis. A closer assessment revealed a large concave lesion located close to the furcation entrance without being obviously connected to it. Periapical radiographs confirmed the presence of a lesion in the hard tissues of the root overlapping the furcation area, and radiolucency of the periapical area of the mesial and distal roots was observed. A tentative diagnosis of tooth fracture with consecutive supraosseous external root resorption was made, and exploratory surgery was performed to disclose the features of the lesion. The direct visual inspection revealed a deep round, conical lesion close to the entrance of the furcation. The base of the lesion was irregular but clean. After removal of a large amalgam restoration, a complete vertical mesio-distal fracture was disclosed. External root resorption can be found in the furcation area of mandibular teeth as a result of chronic inflammation. The radiolucent image is poorly delimited and departs from the well-delimited furcation involvement restricted to bone, which is a consequence of periodontitis. The careful interpretation of the clinical and radiographic signs can assist the clinician to differentiate the diagnosis of root resorption in the furcation area from furcation involvements that result from periodontitis.

Wound healing following regenerative procedures in furcation degree III defects: histomorphometric outcomes

Degree III furcation involvements were surgically created at four first molars in each of three monkeys. Following 6 weeks of healing, full-thickness flaps were elevated. Following 24% EDTA gel conditioning, the defects were treated with one of the following: (1) enamel matrix proteins (EMD), (2) guided tissue regeneration (GTR) or (3) a combination EMD and GTR. The control defects did not receive any treatment. After 5 months of healing, the animals were sacrificed. Three 8 μm thick histological central sections, 100 μm apart, were used for histomorphometric analysis in six zones of each tooth either within the furcation area or on the pristine external surface of the root. In all specimens, new cementum with inserting collagen fibres was formed. Following GTR or GTR + EMD, cementum was formed up to and including the furcation fornix indicating complete regeneration on the defect periphery. Periodontal ligament fibres were less in all four modalities compared to pristine tissues. In the teeth treated with GTR and GTR + EMD a higher volume of bone and periodontal ligament tissues was observed compared to EMD. After 5 months of healing, regenerated tissues presented quantitative differences from the pristine tissues. In the two modalities where GTR alone or combined with EMD was used, the regenerated tissues differed in quantity from the EMD-treated sites.

Alteration of bFGF expression with growth and age in rat molar periodontal ligament

To test the hypothesis that immunohistochemical changes in expression of basic fibroblast growth factor in the periodontal ligament do not change with age. Thirty male Wistar-ST rats were divided into growing groups (5, 9, and 15 weeks of age) and aging groups (6, 12, and 18 months of age). Serial sagittal sections (5 microm thick) were cut parallel at the distobuccal roots of the maxillary first molar. Paraffin-embedded tissue sections were stained with hematoxylin and eosin and rabbit polyclonal antibodies to basic fibroblast growth factor. The number and the area of basic fibroblast growth factor-immunoreactive cells in the periodontal ligament of the maxillary first molar decreased with age. The number of basic fibroblast growth factor-immunoreactive cells was much greater in the root furcation area, which experiences the greatest effect of occlusal force. Regardless of age, the production of basic fibroblast growth factor in the periodontal ligament may occur subject to functional demand. The hypothesis is rejected. The expression of basic fibroblast growth factor in the periodontal ligament decreased with age.

Hypertension May Affect Tooth‐Supporting Alveolar Bone Quality: A Study in Rats

This study evaluates the ligature-induced bone loss (BL) and quality of tooth-supporting alveolar bone in spontaneously hypertensive rats (SHRs) by histometric, histochemical, and immunohistochemical analyses and assesses the effects of lercanidipine on these parameters. Wistar rats and SHRs were assigned to one of the following groups: normotensive rats (n = 15), untreated SHRs (n = 15), and treated SHRs (n = 15). The latter group was treated daily with lercanidipine for 45 days. Two weeks after the beginning of drug administration, the first right mandibular molar received a cotton ligature, whereas the contralateral tooth was left unligated. The following parameters were analyzed in the furcation area of decalcified histologic sections: BL, bone density (BD), number of positive cells for tartrate-resistant acid phosphatase (TRAP+), and expression of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG). In ligated teeth, no significant differences among groups were found regarding BL, TRAP+ cells, and the ratio of RANKL/OPG+ cells (P >0.05), although the expression of RANKL was decreased in the treated SHR group (P <0.05). Increased BL and decreased BD were observed around unligated teeth of the untreated and treated SHR groups (P <0.05). In the furcation area of the unligated teeth, the untreated SHR group presented a higher number of TRAP+ cells and higher ratio of RANKL/OPG+ cells compared to the other groups. SHRs present harmful alterations in the quality of tooth-supporting bone, independently of inflammation. In addition, the administration of lercanidipine for 45 days decreased the expression of bone-resorption markers.