The roles of autophagy and hypoxia in human inflammatory periapical lesions.

AIM: To determine the expressions of hypoxia-related [hypoxia-inducible transcription factors (HIF)-1α, BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and phospho-adenosine monophosphate activated protein kinase (pAMPK)] and autophagy-related [microtubule-associated protein 1 light chain 3 (LC3), beclin-1 (BECN-1), autophagy-related gene (Atg)5-12, and p62] proteins in human inflammatory periapical lesions. METHODOLOGY: Fifteen samples of radicular cysts (RCs) and 21 periapical granulomas (PGs), combined with 17 healthy dental pulp tissues, were examined. Enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin (IL)-1ß cytokine; immunohistochemical (IHC) and Western blot (WB) analyses were employed to examine autophagy-related and hypoxia-related proteins. Transmission electron microscopy (TEM) was used to explore the ultrastructural morphology of autophagy in periapical lesions. Nonparametric Kruskal-Wallis tests and Mann-Whitney U-tests were used for statistical analyses. RESULTS: ELISA revealed a significantly higher (P < 0.001) IL-1ß expression in periapical lesions than in normal pulp tissue. Immunoscores of IHC expressions of pAMPK, HIF-1α, BNIP3, BECN-1 and Atg5-12 proteins in periapical lesions were significantly higher (P < 0.001) (except BECN-1) than those in normal pulp tissue. The results of IHC studies were largely compatible with those of WB analyses, where significantly higher (P < 0.05) expressions of hypoxia-related and autophagy-related proteins (except BECN-1, p62 and LC3II in WB analyses) in periapical lesions were noted as compared to normal pulp tissue. Upon TEM, ultrastructural double-membrane autophagosomes and autolysosomes were observed in PGs and RCs. CONCLUSIONS: Autophagy associated with hypoxia may play a potential causative role in the development and maintenance of inflamed periapical lesions.

[Endodontics in motion: new concepts, materials and techniques 5. The dynamics of the periapical laesion]. / Endodontologie in beweging: nieuwe concepten, materialen en technieken 5. De dynamiek van de periapicale laesie.

Periapical laesions are a frequently occurring phenomenon, in both untreated teeth and teeth which have undergone endodontic treatment. Various factors have been found to positively influence the effectiveness of endodontic treatment, which is defined by a lack of clinical symptoms and also the absence or shrinkage of the periapical laesion. The chance of a painful exacerbation of a persistent periapical laesion is small, even if the area of the laesion has expanded, which happens in approximately 50% of the cases. The survival of endodontically treated teeth with a periapical laesion is 87% after 10 years. Restorative reasons frequently are the main reason for extraction and the presence of a periapical laesion is seldom the reason for losing a tooth. The influence of the periapical laesion on general health is still unclear.

Spontaneous resolution of a periapical lesion during orthodontic treatment: a case report.

UNLABELLED: Teeth with periapical lesions can undergo successful orthodontic treatment, but conventional protocols indicate that such teeth should be endodontically stabilized prior to such treatment. A case report is presented where such endodontic stabilization was not possible, yet a chronic periapical lesion resolved as orthodontic treatment progressed. This paper will discuss the possible causes of the initial lesion, and reasons why it resolved without endodontic treatment. CLINICAL RELEVANCE: This report illustrates the possible combined roles of trauma, occlusion and periodontal disease in the development of a perio-endo lesion, and how orthodontic treatment potentially relieved some of the exacerbating factors, thus enabling resolution of the infection without endodontic treatment.

Healing of extraction sockets in collagenase-2 (matrix metalloproteinase-8)-deficient mice.

Matrix metalloproteinase-8 (MMP-8) participates in skin wound healing and inflammation. We hypothesized that MMP-8 plays a role in wound healing after tooth extraction and in periapical inflammation. Bone formation, collagen metabolism, and inflammation in tooth extraction socket and in periapical lesions were analyzed in wild-type mice and in MMP-8-deficient (MMP-8(-/-)) mice. New trabecular bone area in the extraction sockets and in periapical lesions were similar in both groups. In extraction sockets significantly more type III procollagen was synthesized, and the neutrophil and MMP-9 levels were lower in MMP-8(-/-) mice. The amount of Fas ligand, identified as a substrate for MMP-8, was lower in alveolar mucosa but higher in alveolar bone of MMP-8(-/-) mice. These results indicate that MMP-8 can modulate inflammation and collagen metabolism of alveolar bone and mucosa.

Pain associated with root canal treatment.

AIM: To determine the pain experienced by patients during root canal treatment and to correlate with age and gender, pulpal diagnosis, previous periapical status, dental characteristics and length of treatment. METHODOLOGY: One hundred and seventy-six patients (68 men and 108 women), with ages ranged from 6 to 83 years, were randomly recruited. Patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain experienced during root canal treatment. RESULTS: The mean pain level during root canal treatment was 1.2 +/- 0.8 in a VAS between 0 and 10. Fifty-four per cent of patients did not experience pain. There were no significant differences in relation to gender or age groups. Mandibular teeth had a significantly (P < 0.05) higher percentage incidence of pain in comparison with maxillary teeth. Pain was absent in 63% of anterior teeth compared with 44% in posterior ones (P < 0.01). Interventions shorter than 45 min resulted in a significantly higher percentage of pain absence (P < 0.05). Root canal treatment was significantly (P < 0.05) more painful in teeth with irreversible pulpitis and acute apical periodontitis compared to the group with necrotic pulps and chronic apical periodontitis (P = 0.049). CONCLUSIONS: Root canal treatment in teeth with irreversible pulpitis and acute apical periodontitis was more painful. Age, tooth type and length of the treatment were factors associated with increased risk for pain experienced during the procedure. Knowledge of pain levels endured by patients will allow dentists to decide when to use supplemental local anaesthesia.

Periapical Healing in Single-visit Endodontics under General Anesthesia in Special Needs Patients.

INTRODUCTION: The aim of this study was to determine the prognostic factors of periapical healing of teeth after single-visit nonsurgical endodontic treatment under general anesthesia in special needs patients. METHODS: This retrospective study collected 448 teeth from 241 patients (mean age = 27.4 years, standard deviation = 13.9 years). A total of 271 teeth (60.5%) with clinical and radiographic follow-up records longer than 12 months (mean [standard deviation] = 56.1 [27.9]) were included in the outcome analysis. Demographic, systemic, and dental information about the cases were compared between the healed and nonhealed groups using the Pearson chi-square test. Factors contributing to periapical healing were determined with multivariate logistic regression analysis. RESULTS: Complete periapical healing without clinical signs was observed in 221 teeth (81.5%), uncertain healing with decreased size of the periapical lesion was shown in 43 teeth (15.9%), and no reduction in lesion size was observed in 7 cases (2.6%). In the multivariate analysis, diet type, oral hygiene maintenance, pulp vitality, and root filling length were detected as contributing factors for complete resolution of periapical lesions (P < .05). CONCLUSIONS: Successful outcomes of single-visit endodontic treatment under general anesthesia were shown in special needs patients. The prognoses were influenced by the clinical circumstances of the patients and the preoperative conditions of their teeth.

Periapical Microsurgery: A 4-dimensional Analysis of Healing Patterns.

INTRODUCTION: Currently, the success of periapical microsurgery is determined by the restoration of the lamina dura and the elimination of symptoms. However, inadequate site preservation may prevent later implant placement. Although not possible before, the advent of cone-beam computed tomographic imaging and computer-aided registration allows for indirect and accurate 3-dimensional analysis of the surgical site over time. This study analyzed the volumetric healing pattern of the buccal plate after periapical microsurgery, with a specific focus on the buccolingual thickness of bone and the regression of the surface contour of the cortical plate. METHODS: Thirty-seven patients were scheduled for follow-up at least 1 year after periapical microsurgery (median = 25 months, total range = 12-31 months). Volumetric healing was analyzed by converting preoperative and postoperative cone-beam computed tomographic images into digital 3-dimensional models. The models were then registered to be able to analyze the changes in volume over time. Analysis was completed using Geomagic software (3D Systems, Rock Hill, SC), which allowed for registration of the volumes, calculation of volume change, and calculation of the margin of error. RESULTS: Twelve cases qualified for volumetric analysis. The median volumetric reduction of the cortical plate was -24.9 mm3 (interquartile range = -8.94 to -67 mm3), with an average linear error of 0.7 mm. This corresponded to an average loss in buccolingual dimension of 0.1-0.25 mm. Regression of the cortical plate was within the margin of error in all cases. CONCLUSIONS: After periapical microsurgery, and in the absence of grafting materials or membranes, healing occurs with little to no regression of the buccal cortical plate.

Craniofacial and oral alterations in patients with Neurofibromatosis 1.

ABTSRACT: Neurofibromatosis type 1 (NF1) is one of the most common inherited syndromes. The literature on craniofacial alterations associated with NF1 has been limited and partially contradictory. This review is based on literature search and the results of the clinical study "Craniofacial and Oral Alterations and Speech in patients with Neurofibromatosis 1", carried out at the University of Turku and Turku University Hospital, Finland in 2006-2012. By the end of 2012, a total of 110 NF1 patients, 54 female and 56 male patients, were examined.A part of our results confirms pre-existing understanding, a part is contradictory to previous considerations based mainly on case reports, and some are entirely novel. Specifically, our results confirmed that enlargement the mandibular canal is the most common abnormality of the mandible in patients with NF1. It should be noted, however, that this finding does not require treatment. Caries was not a major problem. In fact, it was less frequent in NF1 patients compared to reference population. These findings abrogate some previous perceptions. Novel findings of our project include periapical cemental dysplasia in females; short jaws, a finding which usually does not affect bite; and immunohistological analysis of oral mucosal abnormalities. Pioneering study on speech showed that various deviations were very common: As many as 94% of the participants showed some alterations.To conclude, the awareness of craniofacial alterations common in NF1would help avoiding unnecessary and even harmful involvement, e.g. of periapical cemental dysplasia or enlarged mandibular canal which do not require treatment.

Periapical Lesions Increase Macrophage Infiltration and Inflammatory Signaling in Muscle Tissue of Rats.

INTRODUCTION: Our previous studies have shown that periapical lesions (PLs) in rats cause systemic disorders such as increased tumor necrosis factor-α plasma levels, insulin resistance, and impairment in insulin signal transduction in muscle tissue. However, the mechanisms involved in these alterations are not fully understood. Under chronic inflammatory conditions such as obesity, it has been shown that the skeletal muscle is affected by inflammation, and the number of resident macrophages that are associated with impairments of insulin action and sensitivity is increased. This study aimed to investigate the presence of macrophages, activation of inflammatory pathways in muscle tissue, glycemia, and insulinemia of rats with PLs. METHODS: Sixty Wistar rats were distributed into a control group; a group with 1 PL (1PL), which was induced in the right maxillary first molar; and a group with 4 PLs (4PL), which were induced in the right upper and lower first and second molars. We quantified macrophage content by immunohistochemistry for the F4/80 protein. We evaluated Jun N-terminal kinase and IKKα/ß phosphorylation status in the muscle tissue by Western blotting. Serum levels of lipopolysaccharide (LPS) and HSP70 and plasma levels of glucose and insulin were assessed by using commercial kits. RESULTS: The 1PL and 4PL groups showed increase in macrophage content, IKKα/ß, and Jun N-terminal kinase phosphorylation status, serum LPS and HSP70 levels, and insulin resistance and no changes in glycemia and insulinemia compared with the control group. There was no difference in these parameters between the 1PL and 4PL groups. CONCLUSIONS: PLs promoted an increase in macrophage infiltration, activation of inflammatory pathways in muscle tissue, and serum concentrations of HSP70 and LPS in rats. The present study improves the knowledge on the impact of oral inflammations on the development of systemic alteration, which can induce insulin resistance.

Role of Periapical Diseases in Medication-Related Osteonecrosis of the Jaws.

OBJECTIVE: The present study aimed to investigate the role of periapical diseases in inducing medication-related osteonecrosis of the jaws (MRONJ) using an ovariectomized (OVX) mice model. MATERIALS AND METHODS: Twenty C57BL/6N female mice were randomly assigned to two groups. All mice were subjected to bilateral ovariectomy and then treated with oncologic dose of zoledronic acid (ZA) or vehicle for twelve weeks. Eight weeks after commence of drug administration, a pulpal exposure (PE) operation was performed on the first right lower molar to induce periapical periodontitis; the contralateral non-PE tooth was used as control. All animals were sacrificed four weeks after pulpal exposure, and the mandibles were harvested for radiological and histomorphometrical analysis. RESULTS: Micro computed tomography (µ-CT) examination demonstrated that periapical diseases significantly increased alveolar bone resorption, and the resorption was greatly attenuated by ZA treatment. Concurrent ZA therapy significantly increased bone density and histological osteocyte necrosis in the presence of periapical lesions. CONCLUSION: ZA treatment reduced bone absorption resulting from periapical disease but increased the risk of developing MRONJ in the ovariectomized mouse model.

Healing of induced periapical lesions in ferret canines.

A previous study showed that the ferret canine is an appropriate model for inducing periapical lesions. Ferret canines were used in this study to study changes in periapical lesions after root canal treatment (RCT). After periapical pathosis was induced in the maxillary and mandibular canines of six ferrets, RCT was performed on three of the four canines in each animal. Each ferret received periodic intraperitoneal injections of Procion red dye. Two animals were killed at each of 4, 8, and 12 wk after RCT. Apices and surrounding lesions were evaluated radiographically, histologically, and by fluorescent microscopy. Periapical radiolucencies increased in size during induction but showed no changes after RCT. Lesions in untreated teeth showed features of granulomatous inflammation, mainly the presence of macrophages and lymphocytes. After RCT, there was histological evidence of healing in the form of cementum deposition, increased vascularity, and increased fibroblastic and osteoblastic activity. Fluorescent staining showed cementum deposition of variable thickness in the treated specimens.

An observation of the healing process of periapical lesions by digital subtraction radiography.

The purpose of this study was to evaluate the efficacy of digital subtraction radiography using a direct digital imaging system in the follow-up study of endodontically treated teeth. The RVG-S was used as a direct digital imaging system. The intraimage variation of the original RVG-S image caused by dark current and sensitivity variations among pixels was corrected by pixel-to-pixel. The interimage variation was further corrected using a copper step-wedge attached to the sensor. Standardized images were obtained from the same geometrical setup during the follow-up. Pixel values at the regions of interest positioned on the periapical lesion increased after the endodontic treatment, and this change continued during the observation period up to 545 days. The subtraction method with direct digital radiography will be a useful tool to evaluate the healing process in endodontic treatments.

Periapical lesion progression with controlled microbial inoculation in a type I diabetic mouse model.

Uncontrolled or poorly controlled diabetes mellitus may be a risk factor for the development of large and/or debilitating periapical infections. The objectives of this investigation were to: (i) determine the effect of diabetes mellitus on the pathogenesis of periapical lesions with or without specific bacterial inoculations at the exposure sites, and (ii) test the sensitivities of two microbiological techniques in detecting the persistence of the bacterial inoculum in exposed pulps of nonobese diabetic (NOD) mice. Periapical lesions were induced in first molars of 29 female NOD mice and 31 BALB/c controls. Acute (1-2 wk) or chronic (5 wk) exposures were either inoculated with a mixture of facultative and anaerobic bacteria or exposed to oral flora without inoculations. After death the teeth in the chronic groups were analyzed for the presence of the inoculated bacteria by culturing and by polymerase chain reaction amplification of 16S rDNA. Periapical lesion size was measured histomorphometrically and the interleukin-6 content was measured immunohistochemically. The mortality among NOD mice with inoculated and sealed exposures was 83%, compared with 29% for BALB/c mice. In the inoculated and uninoculated chronic NOD mice groups, 38% of the animals versus none of the BALB/c mice died. The chronic uninoculated NOD mice lost significantly more weight at the time of death than controls. Polymerase chain reaction was more sensitive than culturing in detecting the inoculated anaerobic bacteria. In the animals that survived to the predetermined time periods, lesion size and interleukin-6 content in NOD and BALB/c mice were not statistically different.

Effect of teeth with periradicular lesions on adjacent dental implants.

OBJECTIVES: It is generally accepted that dental implants should not be placed in infected sites. However, the effect of periradicular infections of natural teeth on adjacent osseointegrated implants is less understood. The purpose of this study was to evaluate effects of periradicular lesions on osseointegration of existing implants. Study design Forty titanium solid root-form implants were placed close to premolars in dogs. After healing following implant placement, the adjacent premolars were treated in 1 of 4 ways: group A, no treatment of the adjacent premolar; group B, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar; group C, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar and surgical detoxification of the implant surface; and group D, induction of periradicular lesion and no treatment of the tooth. After 7(1/2) months, block sections were prepared and the percentage of osseointegration was analyzed histomorphometrically. RESULTS: The average integration for implants in groups A-B was 54%, 74%, 56%, and 68%, respectively. One-way analysis of variance demonstrated no difference between the 4 groups ( P =.518). CONCLUSIONS: The results of this study indicate that teeth with periradicular lesions do not adversely affect adjacent titanium solid root-form implants.

Comparison of clinical outcome of periapical surgery in endodontic and oral surgery units of a teaching dental hospital: a retrospective study.

OBJECTIVES: The aims of this retrospective study were (1) to compare the outcome of periapical surgery performed in endodontic and in oral surgery units of a teaching dental hospital and (2) to evaluate the influence of factors affecting outcome. STUDY DESIGN: A total of 176 teeth (endodontic unit, 83; oral surgery unit, 93) surgically treated more than 4 years previously were examined clinically and radiographically by means of strict criteria. Multiple logistic regression analysis was used. RESULTS: The rate of complete healing for patients treated in the endodontic unit (37.4%) was significantly (P = .009) higher than that for patients treated in the oral surgery unit (19.4%). The technical quality of surgery (P < .001), placement of root-end filling (P = .039), absence of a preoperative periapical lesion (P = .042), absence of a post (P = .047), and presence of an adequate coronal restoration (P = .056, odds ratio = 3.71) had significant effects on treatment outcome. CONCLUSION: The technical quality of periapical surgery, the presence of a periapical lesion, and adequate apical and coronal seal are important prognostic determinants of successful periapical surgery.

Reversible and irreversible painful pulpitides: diagnosis and treatment.

The foregoing clinical evidence indicates that when pain is severe, or when mild to moderate pain is present with a previous history of pain in the aching tooth, with or without periapical radiolucency, the tooth is in the IRPP category. Treatment dictates endodontic therapy or extraction. On the other hand, when clinical evidence indicates that the pain is mild or moderate with no previous history of pain, normal pulp vitality, and there is no positive percussion sign, the pulp is in the RPP category. Treatment dictates indirect or direct pulp capping in teeth with or without periapical radiolucency. The success rate favours teeth with no periapical radiolucency, 98%; in teeth with periapical radiolucency the success rate is less favorable, 43%. Efforts should be made to maintain pulp vitality. Endodontic therapy can always be done, if in time the pulp develops necrosis.

Pulpal injury: pathology, diagnosis and periodontal reactions.

Diagnosis of pulpal disease can be difficult due to the lack of diagnostic signs and symptoms available to the practitioner. An understanding of the possible underlying pathological processes, combined with an exact assessment of the pain history, and appropriate clinical tests, should aid the practitioner in determining the nature of pulpal inflammation, and differentiating it from dentine sensitivity and cracked teeth. The responses of the pulp to traumatic injury to the periodontal membrane (PDM) require special consideration, particularly with respect to the assessment of pulp vitality, and the determination of cases requiring pulp extirpation in order to avoid inflammatory root resorption. Although the pulp is relatively isolated from the rest of the dentoalveolar complex by a dentine/cementum barrier, it is important to remember that it can communicate with the PDM through apical and lateral foramina, and areas of damaged cementum. Hence, it is a priority to both preserve the integrity of the cemental layer in cases of traumatic injury and periodontal disease, and to prevent the inflammation and resorption associated with periapical lesions by accurate diagnosis of irreversible pulpitis and pulp necrosis, followed by appropriate endodontic debridement procedures.

Management of wide open apices in non-vital permanent teeth with Ca(OH)2 paste.

A retrospective study on 15 non-vital immature incisor teeth was done using Ca(OH)2 Pulpdent paste. A success rate of 100 percent was achieved within one year. The variables influencing the time taken for apexification were also evaluated. The teeth were followed up to a period of 24 months. It was found that older children having narrow open apex had a shorter treatment time than the younger children (NS); teeth without periapical infection showed some amount of root growth and closing of apex that was faster than those with periapical infection (p < 0.001). The calcified bridge formed following apexification is a porous structure. This investigation provides information about the time taken and procedure required to achieve apical barrier formation in non-vital immature incisors.

Combating inadequate anesthesia in periapical infections, with sodium bicarbonate: a clinical double blind study.

INTRODUCTION: Local anesthetics are generally much less effective when administered in inflamed tissues. PURPOSE: This study was conducted to validate the addition of sodium bicarbonate in local anesthetics to increase its effectiveness as local infiltrations in teeth associated with periapical infections. METHODS: Two hundred subjects requiring extraction of maxillary teeth with periapical infections were enrolled. These subjects were divided in two groups of 100 subjects each. One group received local infiltration with 2 % lignocaine and 1:80,000 adrenaline, and the other group received local infiltration with sodium bicarbonate as an adjunct to the above mentioned local anesthetic solution. All extractions were performed using a consistent intra-alveolar technique by a single operator. Both the patient and the operator were blinded to the contents of local anesthetic solution. Data related to the onset of action of local anesthesia, pain experienced by the patient while undergoing extraction on two scales-"the visual analog scale and the verbal response scale", and any requirement of repeated injections during the procedure was recorded. RESULTS: Clinical and statistical data confirmed that the addition of sodium bicarbonate in local anesthetics did increase the efficacy of local anesthesia in inflamed tissues. CONCLUSION: It has been observed in this study that the action of sodium bicarbonate in local anesthetics increases the pH levels of these solutions, thus possibly making them more effective in an acidic environment.

Periapical disease and bisphosphonates induce osteonecrosis of the jaws in mice.

Osteonecrosis of the jaw (ONJ) is a well-recognized complication of antiresorptive medications, such as bisphosphonates (BPs). Although ONJ is most common after tooth extractions in patients receiving high-dose BPs, many patients do not experience oral trauma. Animal models using tooth extractions and high BP doses recapitulate several clinical, radiographic, and histologic findings of ONJ. We and others have reported on rat models of ONJ using experimental dental disease in the absence of tooth extraction. These models emphasize the importance of dental infection/inflammation for ONJ development. Here, we extend our original report in the rat, and present a mouse model of ONJ in the presence of dental disease. Mice were injected with high dose zoledronic acid and pulpal exposure of mandibular molars was performed to induce periapical disease. After 8 weeks, quantitative and qualitative radiographic and histologic analyses of mouse mandibles were done. Periapical lesions were larger in vehicle-treated versus BP-treated mice. Importantly, radiographic features resembling clinical ONJ, including thickening of the lamina dura, periosteal bone deposition, and increased trabecular density, were seen in the drilled site of BP-treated animals. Histologically, osteonecrosis, periosteal thickening, periosteal bone apposition, epithelial migration, and bone exposure were present in the BP-treated animals in the presence of periapical disease. No difference in tartrate-resistant acid phosphatase (TRAP)+ cell numbers was observed, but round, detached, and removed from the bone surface cells were present in BP-treated animals. Although 88% of the BP-treated animals showed areas of osteonecrosis in the dental disease site, only 33% developed bone exposure, suggesting that osteonecrosis precedes bone exposure. Our data further emphasize the importance of dental disease in ONJ development, provide qualitative and quantitative measures of ONJ, and present a novel mouse ONJ model in the absence of tooth extraction that should be useful in further exploring ONJ pathophysiological mechanisms.