Mesial Root Surfaces Research Articles

Morphometric Measurements of Root Anatomic Areas of Maxillary First Premolar Teeth in a Representative Nepalese Population

Background The prognosis of furcation involved maxillary first premolar is typically guarded to poor. The presence of concavities in the root trunk and the positioning of the roots in the buccal and palatal regions of the teeth are responsible for its challenges during instrumentation and control plaque. We aimed to access the presence of concavities on the root surface as well as morphometric measurement of the root trunk dimensions in the maxillary first premolar teeth in Nepalese population.MethodsA cross-sectional quantitative study was conducted in the Department of Periodontics and Oral Implantology, College of Medical Sciences (CoMS). Extracted Maxillary first premolar teeth were evaluated for the number of roots, morphometric measurement of the root trunk, root divergence, and root length. The presence of concavities was recorded on the mesial and distal root surface at cervical, middle, and apical thirds of the root.ResultsThe overall mean root trunk length was less on the mesial aspect than on the distal aspect (6.39 ± 2.54 and 8.08 ± 3.48 respectively). The prevalence of root surface concavity on the cervical third at the mesial aspect (90 %) was found to be higher than in the distal aspect (15%) Conclusions Owing to the higher prevalence of root surface concavity on the cervical third of mesial aspect, use of mini-bladed curettes is recommended for the effective root surface debridement of the periodontally involved maxillary first premolar tooth. Patients with periodontally involved maxillary first premolar should be advised to use interdental brushes rather than dental floss.

Three-dimensional positions of the center of resistance of the maxillary canine distal movement under orthodontic force loading.

Using finite-element analysis, we aimed to determine the center of resistance (CRes) of the maxillary canine for setting orthodontic forces. The inclination of the canine was measured by first loading from the mesial to the distal side of the mesial root surface, then the position and direction of the load that minimized the inclination were investigated. The CRes was defined as the set of midpoints of the minimum distances between two inclination lines. Twenty-one CRes values were calculated from a set of seven lines. These CRes data were then aggregated as a 95% confidence ellipsoid of width 0.170×0.016×0.009 mm with center points 4.269, 0.224, and 4.315 mm in the apical, mesial, and lingual directions from the origin, respectively. Further studies are required to effectively apply the CRes identified in this study to clinical applications.

PREVALENCE OF IATROGENIC PERFORATIONS ACCORDING TO THEIR LOCATION AND AFFECTED ROOT SURFACES

Background: The location of the endodontic perforation has shown a strong correlation with the healing process and successful outcome. The aim of this study was to determine the prevalence of iatrogenic perforations according to their location and affected root surfaces. Materials and methods: Over a period of 7 years, 100 cases of iatrogenic root perforations were recorded from the digital radiographs of each case. The perforations were classified according to the following criteria: (1) perforation location – cervical, furcation, stripping, lateral, and apical (2) affected root surface. The prevalence of different types of perforation was calculated and subjected to statistical analysis. Results: Among all types of perforations, the most common are those located in the furcation area of the molars (46%), followed by lateral root perforation (35.8%). The mesial root surfaces are most often affected by iatrogenic perforations (71.9%), followed by the distal ones (21%). Conclusion: Prior to root canal treatment, it is essential to assess the morphologic conditions in the key areas prone to iatrogenic perforations.

Evaluation of the Relationship Between Maxillary Sinus Wall and Maxillary Canines and Posterior Teeth Using Cone-Beam Computed Tomography

BackgroundThe proximity between the maxillary sinus and dental roots may impede orthodontic tooth movement. This study aimed to explore the relationship between the maxillary sinus wall (MSW) and maxillary canines and posterior teeth using cone-beam computed tomography (CBCT).Material/MethodsCBCT images (317) were examined for whether the mesial, distal, buccal, and palatal surfaces of the examined root contacted the MSW, and the contact distance of each root surface with the MSW was measured. The effects of age and sex were analyzed using logistic regression and linear regression analyses.ResultsThe highest contact ratios with the MSW (ranging from 62.0% to 73.2%) were observed at the palatal root surfaces of the first molar mesiobuccal and distobuccal roots (1M MB and DB), the buccal root surface of the first molar palatal roots (1M P), and the mesial and buccal root surfaces of the second molars (2M), followed by the distal root surface of the second premolars (2PM) and the mesial root surfaces of the 1M MB and P (ranging from 49.2% to 59.3%). At these root surfaces, the contact ratios decreased with age (P<0.05), but the lowest still reached a range of 29.4% to 57.9% in the 30- to 47-year-old group.ConclusionsThe 2PM distal root surface, the 1M MB mesial and palatal root surfaces, the 1M DB palatal root surface, and the 1M P and 2M mesial and buccal root surfaces most frequently contacted the MSW. Clinicians should observe the contact of root surfaces with the MSW, even in aged patients.

Root Surface Temperature Increases during Root Canal Filling In Vitro with Nd:YAG Laser-Softened Gutta-Percha.

The aim of this in vitro study was to measure the temperature increases produced on the mesial and vestibular root surfaces of premolar teeth during a laser-softened gutta-percha obturation technique. We studied 12 extracted human premolar teeth with a single canal. After root canal cleaning and shaping, the teeth were obturated with gutta-percha that had been softened with a neodymium-doped yttrium aluminium garnet (Nd:YAG) laser (CTL 1503) at a wavelength of 1.064 nm. The laser setup parameters included a 30 Hz frequency and a 200 mJ/pulse with optical fiber tips of 0.320 mm diameter. A sectional warm gutta-percha condensation was used. Temperature changes on the whole mesial and vestibular outer surfaces of the roots were measured at approximately 2 s intervals with an infrared thermal imaging camera. A significantly higher increase in temperature was observed for the mesial root surface (7.5°C) compared to the vestibular surface (3.7°C) (p ≈ 0). The findings suggested that root canal filling with Nd:YAG laser-softened gutta-percha in premolar teeth is not likely to damage the surrounding periradicular tissues. To obtain valid temperature results, the measurement should be performed on the surface with the thinnest root wall.

Furcation: the truth behind the roots!!!

Background: Complex anatomic morphology of bifurcations and trifurcations predisposes multirooted teeth to plaque accumulation leading to periodontal infection. This poses a great difficulty in treatment planning and management of these furcation defects.Assessing the degree of furcation involvement depending on external tooth surface points may lead to the underestimation of positive treatment outcomes. Aim: To determine the buccolingual width of the furcation of mandibular molar and compare it with buccolingual width of mesial and distal roots at the level of root separation. Materials and Methods: 40 randomly selected mandibular molars were analyzed in which 20 first molars and 20 second molars were included. Four horizontal buccolingual distances were evaluated: CEJ, Furcation entrance/ roof width (FE), Mesial root width (MRW), andDistal root width (DRW).Discrepancies between FE measurements and MRW, DRW, and CEJ were determined in each tooth by subtracting the FE measurements respectively from MRW, DRW, and CEJ. Results: The width of the furcation entrance has a mean of 5.41 ± 0.67 mm varying from 4 to 7 mm in first molars and a mean of 5.18 ± 0.64 mm varying from 4 to 6 mm in second molars. In this study, the FE is measured more internally than the mesial and distal root surfaces and therefore, the FE is smaller than MRW and DRW.From this, it is evident that the actual furcation width is much less than the CEJ width, MRW and DRW measured buccolingually. Conclusion: Clinical measurements of horizontal probing depth that use the external surfaces of roots as reference points overestimate the true anatomical component of furcation involvement in mandibular molars. Conversely, positive treatment outcomes in these teeth may be underestimated.Thus, estimation of actual furcation entrance width before a surgical intervention is necessary and can influence the prognosis of involved teeth after different regenerative therapies for furcation defects. Key words : Furcation therapy, molar anatomy, periodontal attachment loss/diagnosis, outcome assessment of regenerative therapies.

Root caries on a Paranthropus robustus third molar from Drimolen.

Dental caries is often perceived as a modern human disease. However, their presence is documented in many early human groups, various nonhuman primates and, increasingly, our hominin ancestors and relatives. In this study, we describe an antemortem lesion on the root of a Paranthropus robustus third molar from Drimolen, South Africa, which likely represents another example of caries in fossil hominins. The molar, DNH 40, is dated to 2.0-1.5 Ma and displays a lesion on the mesial root surface, extending from the cementoenamel junction 3 mm down toward the apex. The position and severity of the lesion was macroscopically recorded and micro-CT scanned to determine the extent of dentine involvement. A differential diagnosis indicates root caries, as the lesion is indistinguishable from clinical examples. Although necrotic in appearance, external tertiary dentine is evident on a micro CT scan. Gingival recession and/or continuous eruption of the tooth as a result of extensive occlusal wear would have occurred to facilitate caries formation. Therefore, the lesion is likely linked to relative old age of this individual. This new example increases the total number of carious lesions described in P. robustus teeth to 10, on occlusal, interproximal, and now, root surfaces. Beyond the consumption of caries-causing food, caries formation would have also required the presence of requisite intraoral cariogenic bacteria in this individual and the species. Of interest, the presence of tertiary dentine on the outward surface suggests the DNH 40 lesion may have been arrested, that is, no longer active, perhaps relating to a change in diet or oral microbiome just prior to the individual's death.

Repair of root canal perforation by different materials

Background: The aim of this in vitro study was to compare sealing ability of Mineral Trioxide Aggregate (MTA), Glass ionomer cement (GIC) and Epiphany obturation system in repairing the iatrogenic lateral root canal perforation. Materials and Methods: Thirty freshly extracted human teeth with single and straight canals were used in this study. These teeth were cleaned and their crowns were removed at the cemento-enamel junction. The roots were instrumented using the step-back technique. A perforation was created on the mesial root surface at about 45- degree angle to the long axis of each root apico-coronally at the middle third by small round bur #1/2 with copious irrigation of 2.5% NaOCL and 17% buffered solution of EDTA was used as the final rinse to remove the smear layer and to prevent the blockage of perforation. The 30 roots were divided randomly in to three groups (10 roots for each group):- Group A: The root canal perforation was repaired by MTA then obturated by lateral condensation technique with gutta-percha and zinc oxide eugenol sealer. Group B: The root canal perforation was repaired by GIC then obturated by lateral condensation technique with gutta-percha and zinc oxide eugenol sealer. Group C: the roots were obturated with Epiphany obturation system by lateral condensation technique. The external surfaces of all roots were coated by two layers of sticky wax except the perforation site then immersed in 2% methylene blue dye for 48 hrs in incubator at 37C°. After that all roots were longitudinally sectioned for linear measurement of dye penetration through the perforation using a stereomicroscope at X40 magnification with calibrated scale ocular grid. Results: The result showed that group A showed the lowest mean of dye leakage (0.77mm) while group C showed the highest mean of dye leakage (4.45mm). Conclusion: Significantly less dye leakage in roots which perforations repaired by MTA than those repaired by GIC and highly significant less dye leakage than those repaired by Epiphany obturation system.

In Vitro Study of Temperature Changes in Pulp Chamber During Root Planing Procedure Using Er:YAG Laser.

To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus. Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec. The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance. The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

A custom made grid to guide placement of temporary anchorage devices

The use of implant anchorage has simplified orthodontic treatment by sparing us the need for patient compliance and the complexity of treatment. One of the most important factors affecting the success of interdental implants is preventing the damage to adjacent roots and periodontal ligament. The most common causes of root damage from mini-implant insertion are improper site selection and an inaccurate angle of drill penetration. We thereby present a custom made modified grid help in more accurate placement of temporary anchorage devices and guide the angle of drill penetration. The grid can be placed anywhere in the oral cavity (buccally, palatally, anteriorly or posteriorly) and it can be attached to the main arch wire, bracket or even on unbounded teeth. The measuring reference grid with two vertical guide arms is connected with a horizontal arm that will later be secured to the adjacent bracket at both ends. The grid includes small squares, which effectively upgrade the efficiency during the orthodontic implant placement. The two vertical guide arms help in maintaining the desired angulation while drilling indicating the mesial and distal root surface of the adjacent teeth.

Initial force systems during bodily tooth movement with plastic aligners and composite attachments: A three-dimensional finite element analysis.

To describe, using a three-dimensional finite element (FE) model, the initial force system generated during bodily movement of upper canines with plastic aligners with and without composite attachments. A CAD model of an upper right canine, its alveolar bone and periodontal ligament, thermoformed plastic aligner, and two light-cured composite attachments were constructed. A FE model was used to analyze the effects of imposing a distal movement condition of 0.15 mm on the aligner (simulating the mechanics used to produce a distal bodily movement) with and without composite attachments. In terms of tension and compression stress distribution, without composite attachments a compression area in the cervical third of the distal root surface and a tension area in the apical third of the mesial surface were observed. With composite attachments, uniform compression areas in the distal root surface and uniform tension area in the mesial root surface were observed. Compression areas in the active surfaces of the composite attachments were also observed. In terms of movement patterns, an uncontrolled distal inclination, with rotation axis between the middle and cervical root thirds, was observed without composite attachment. Distal bodily movement (translation) was observed with composite attachment. In a three-dimensional FE analysis of a plastic aligner system biomechanically supplementary composite attachments generate the force system required to produce bodily tooth movement; the absence of biomechanically supplementary composite attachments favors the undesired inclination of the tooth during the translation movements.

Root Dentin Strain and Temperature Rise During Endodontic Treatment and Post Rehabilitation

This study investigated the effects of endodontic treatment procedures and different post systems rehabilitation steps on the strain and temperature rise on apical and cervical root dentin regions. Twenty-one extracted human canine teeth had two strain gages attached to the distal root surface and two thermocouples attached to the mesial root surface (cervical and apical). The strain and temperature rise were recorded during the following procedures: root canal preparation, final rinse and drying, root canal filling and canal relief. Then the teeth were divided into three groups (n=7), according to the type of post system: CPC, cast post and core; FGP, fiberglass post; and PSP, prefabricated steel post. Data continued to be recorded during the post space preparation, post modeling (only for CPC), post trying and post cementation. Data were subjected to a two-way ANOVA followed by Tukey's test (α=0.05). The post-space preparation caused the highest temperature rise (4.0-14.9 °C) and the highest strain in the apical region during irrespective of post type. The resin cement light-activation resulted in significant temperature increases in the cervical region for all of the groups. The canal relief and the post-space preparation produced highest temperature rises. The CPC post modeling resulted in higher root strain level similarly the level of post preparation. The PSP resulted in highest strain during post trying and post cementation.

In vitro comparison of cone beam computed tomography with different voxel sizes for detection of simulated external root resorption

The present study compared the efficacy of cone beam computed tomography using different voxel sizes in the diagnosis of simulated external root resorption. The presence or absence of simulated defects on buccal, mesial and distal root surfaces of 20 premolars was evaluated. The defects were small (0.26 mm in diameter and 0.08 mm deep), medium (0.62 mm in diameter and 0.19 mm deep) and large (1.05 mm in diameter and 0.24 mm deep), equally distributed on each root surface. Images were obtained using Classic i-CAT cone beam computed tomography with different voxel sizes: 0.12, 0.20, 0.25 and 0.30 mm. Five oral radiologists evaluated the images. Accuracy, sensitivity, specificity, positive and negative predictive values were determined. The sensitivity decreased and specificity increased as voxel size increased. Accuracy values were the highest for the smallest voxel size (0.12 mm). The results for voxel sizes 0.20 mm and 0.25 mm were similar. Positive and negative predictive values were similar in all protocols, except with 0.30 mm, in which they were the lowest. In conclusion, external root resorption was more easily diagnosed when a smaller voxel size was used.

Influence of Cone-Beam Computed Tomography Enhancement Filters on Diagnosis of Simulated External Root Resorption

IntroductionThe aim of this study was to determine if cone-beam computed tomography (CBCT) enhancement filters influence the diagnosis of simulated external root resorption (ERR). MethodsBuccal, mesial, and distal root surfaces of 20 single-rooted premolar teeth were evaluated for the presence or absence of simulated defects. Images were obtained using a Classic i-CAT CBCT device (Imaging Sciences International, Inc, Hatfield, PA) and analyzed by 3 oral radiologists. Evaluations were performed with and without CBCT filters. Accuracy, sensitivity, specificity, and positive and negative predictive values were determined. The McNemar test verified the disagreement between all images versus the gold standard and original images versus images with filters; P values < .05 were considered statistically significant. Inter- and intraobserver agreement was calculated by the kappa test. ResultsThe means of intra- and interobserver agreement ranged from good to excellent. Sharpen 3×3 had the highest sensitivity (0.64), accuracy (0.62), and negative predictive value (0.33). Specificity was the highest (0.56) for S9, Smooth, Smooth 3×3, and Angio Sharpen High filters. Positive predictive values were the highest (0.81) for the Smooth 3×3 and Angio Sharpen High filters. The McNemar test showed statistically significant differences from the gold standard for all images (P < .05) as well as for original images versus images with the Shadow filter (P = .01). The other filters did not show statistically significant differences from the original images. ConclusionsThe influence of enhancement CBCT filters on ERR diagnosis is small. The Sharpen 3×3 filter gave the best results and the Shadow filter the worst results.

Evaluation of reconstructed images with different voxel sizes of acquisition in the diagnosis of simulated external root resorption using cone beam computed tomography

To evaluate the diagnosis of simulated external root resorption in cone beam computed tomography (CBCT) images acquired with different voxel sizes, then reconstructed with the same voxel size. Buccal, mesial and distal root surfaces of twenty single-rooted premolar teeth were evaluated for the presence or absence of simulated resorption defects. Images were obtained using a Classic i-CAT CBCT unit with two different voxel sizes (0.25 and 0.30 mm). Then all images were reconstructed to 0.25 mm voxel size. The McNemar's test was applied to evaluate the agreement between the two protocols (different voxel sizes/reconstruction parameters) with the gold standard (defects created in the root). Accuracy, sensitivity, specificity, positive and negative predictive values were calculated for each voxel and defect sizes. Better sensitivity and accuracy were obtained with 0.25 (0.25 mm) voxel size. Specificity, positive and negative predictive values were highest with the 0.25 (0.30 mm) voxel size. McNemar's test results revealed significant differences between the protocols with the gold standard (P < 0.0001). The results revealed that as the cavity size increased, sensitivity, accuracy, positive and negative predictive values also increased. When correlating the voxel size and root third, better sensitivity, accuracy, positive and negative predictive values were obtained in the middle third. In the diagnosis of simulated external root resorption with the Classic i-CAT CBCT unit, images acquired with 0.30 mm voxel size and reconstructed with 0.25 mm voxel size provided the best protocol with a lower radiation dose than the 0.25 mm voxel size.

Three-dimensional morphology of root and alveolar trabecular bone during tooth movement using micro-computed tomography

To investigate the effects of force magnitude on three-dimensional alveolar trabecular bone structure and root resorption. Twenty-two 11-week-old Sprague Dawley rats were randomly assigned to two groups that received a mesially directed orthodontic force to the upper right first molars at different magnitudes of force, 30 g or 100 g, for 2 weeks. The contralateral molars served as controls. The teeth and alveolar bone around the teeth were dissected from the sacrificed animals and were scanned with micro-computed tomography (CT). Structural properties of the trabecular bone and resorption crater volume on the mesial roots of the maxillary first molars were analyzed. The bone volume fraction of the 30 g group and the 100 g group increased significantly in both groups, and trabecular separation of the 100 g group decreased significantly compared with controls (P < .05). The total root resorption volume in all experimental groups and the resorption volume of the lower distal surface in the 100 g group increased significantly compared with controls (P < .01). The volume of the upper mesial root surface in the 30 g group increased significantly compared with the 100 g group and controls (P < .05). The alveolar trabecular bone was denser after orthodontic force was applied for 14 days. The effects of 30 g and 100 g orthodontic forces on root resorption were different at the upper mesial and lower distal surfaces of the mesial roots of maxillary first molars.

Nafamostat mesilate, a potent tryptase inhibitor, modulates periodontitis in rats

Previous reports have demonstrated increased tryptase-like proteolytic activity in the crevicular fluid of patients with periodontal disease. In the present study, we have investigated the effect of tryptase inhibition with nafamostat mesilate (NM, 6-amino-2-naphtlyl p-guanidinobenzoate dimethansulfonate) on the development of experimental periodontitis in rats. Eighty (80) male Wistar rats were randomly separated into four groups: Control group, NM group (daily 0.1mg/kg body weight of NM, i.p.), Ligature group (ligature placed at lower right first molars), and NM+Ligature group. The amount of alveolar bone loss (ABL) around the mesial root surface of the first mandibulary molar, as well as the myeloperoxidase (MPO) activity, and total proteolytic activity [N-benzoyl-L: -arginine-p-nitroanilide (BApNA) substrate] were determined at 7 and 14days. NM led to significantly (p < 0.05) decreased ABL in animals subjected to ligature-induced periodontitis. Tryptase inhibition prevented the onset of significant ABL at 7days of experiment (0.44 ± 0.16 and 0.60 ± 0.22, p > 0.05, NM+Ligature and Control, respectively) and significantly decreased the ABL at 14days (0.97 ± 0.17 versus 1.82 ± 0.26, p < 0.001, NM+Ligature versus Ligature, respectively). In addition, NM significantly decreased MPO and total proteolytic activity at 14days (p < 0.05). These data provided evidence that tryptase inhibition with NM attenuates gingival granulocyte infiltration and ABL in an experimental model of periodontitis in rats.

Usage of white mineral trioxide aggregate in a non‐vital primary molar with no permanent successor

The aim of this study was to present the treatment and long-term follow-up of a case in which white mineral trioxide aggregate (WMTA) was used in the pulpectomy of a non-vital primary molar with no permanent successor. The physiological, aesthetic and functional consequences of treating primary teeth without permanent successors makes this a unique challenge. In the present case, WMTA was used in the pulpectomy of a primary molar with no permanent successor in an 8-year-old child. The treatment was considered successful. Follow-up examinations showed that root resorption in the mesial root surface, with no infra-occlusion or ankylosis 36 months after treatment. WMTA may be considered as an alternative pulpectomy material for non-vital primary teeth with no permanent successors, although long-term clinical studies are still needed.

Absorption of Nickel, Chromium, and Iron by the Root Surface of Primary Molars Covered with Stainless Steel Crowns

Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ), was analyzed. An energy dispersive X-ray spectrometer (EDS) was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times) were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (P < .001). Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

Influence of Photodynamic Therapy on the Development of Ligature‐Induced Periodontitis in Rats

The purpose of this study was to evaluate, histologically and radiographically, the effect of photodynamic therapy on the progression of experimentally induced periodontal disease in rats. Ligatures were placed at the first mandibular molar in rats. The animals were divided into four groups: group 1 (C) received no treatment; group 2 was treated topically with methylene blue (MB; 100 microg/ml); group 3 was treated with low-level laser therapy (LLLT); and group 4 was treated topically with methylene blue followed by LLLT (4.5 J/cm(2)) (photodynamic therapy; PDT). Rats were sacrificed 5, 15, or 30 days postoperatively. Standardized radiographs were taken to measure bone loss around the mesial root surface of the first molar. Data were analyzed statistically (analysis of variance and Tukey test; P <0.05). A scoring system was used to evaluate the connective tissue, periodontal ligament, and alveolar bone histologically. Data were analyzed statistically (Kruskal-Wallis test; P <0.05). Radiographic examination showed that there was significantly less bone loss in Group PDT compared to Group C at 5 and 15 days postoperatively. There was no significant difference in bone loss at 30 days. At 15 days, the histologic results showed significant differences in the extent of inflammatory reaction in the gingival tissue, with a greater extent of chronic inflammatory reaction in Group LLLT. PDT transiently reduced the periodontal tissue destruction.