Enlargement of the apical foramen of mature teeth by instrumentation and apicoectomy. A study of effectiveness and the formation of dentinal cracks.

OBJECTIVE: In the last few years there have been attempts to revascularize mature necrotic teeth instead of performing a standard root canal treatment. Apical foramen enlargement (AFE) would be necessary for regenerative treatments of mature teeth. In the literature, AFE has been made through apicoectomy and instrumentation. However, no standardized methods have been described yet, which may affect the success of the therapy. Our aim was to describe the effectiveness and damage to dental structures of five methods for AFE. METHODS: Two hundred and ten human teeth were assigned to one control group (n = 10) and four treatment groups (n = 50 each): instrumentation was up to file #80 0.5 mm coronal to the apex (I), at apex level (II), 0.5 mm beyond the apex (III) and apicoectomy at 2 and 4 mm from the apex (IV). The apical foramen diameter was measured before and after treatment. The formation of clinically visible fractures (CVF) and microcracks was analysed clinically and with ESEM, respectively. Thirty-two in situ sheep's teeth were also instrumented, to compare damage in in situ and ex vivo teeth. RESULTS: The foramen diameter was augmented by 0.15, 0.47, 0.54 0.06 and 0.32 mm in human teeth of groups I, II, III, apicoectomy at 2 and 4 mm, respectively. CVF were more frequent as the working length was augmented. No statistical differences were found for microcrack formation. In situ teeth showed significantly less damage. CONCLUSIONS: Instrumentation at apex level seems to be the most effective and least harmful technique for AFE, while apicoectomy is not a useful method.

Reasons for Apical Surgery Treatment in an Underserved New York City Population.

Endodontic retreatment often involves remaking restorations. The total cost may steer the treatment towards surgery. The aim of this study was to retrospectively record the reasons for performing apical surgery in an economically deprived patient population. The clinical reasons (59%) for apical surgery were most common, but the nonclinical (financial) reasons (41%) emerged as a major cause. The finding that 41% of the apicoectomies were performed because of nonclinical constraints is a high figure and may not reflect the situation generally. Still, economic factors potentially play a major role in the selection of surgical versus nonsurgical endodontic retreatment.

Hemisection: A Treatment Option for an Endodontically treated Molar with Vertical Root Fracture.

Vertical root fractures (VRF) in endodontically treated teeth have long been reported and pose diagnostic difficulties. A hemisection/root resection procedures removes the fractured fragments completely, and retains a portion of the compromized tooth offers a predictable treatment option. The key to this rests in ideal case selection involving balancing all indications and contraindications. The success of the treatment depends on careful case selection based on a firm set of guidelines. This article presents a case with VRF in an endodontic treated molar. This article describes the case of a 65-year-old man with a VRF on the mesial root and a healthy periodontium supporting the distal root making it ideal for retention as well as restoration and support of the final prosthesis. Also, the patient was motivated to try and save as much of the tooth as possible. Postoperatively no untoward complication was reported making it an alternative treatment option in patients with VRF in a molar, willing to retain the remaining tooth portion. With all other factors balanced, it allows for retaining the remaining intact portion of the tooth structure.

Experimental ex vivo traumatic intrusion in the mandibular incisors of the farm pig, Sus scrofa.

BACKGROUND/AIM: Traumatic intrusion of incisor teeth occurs frequently in young children, as well as in teens and adults; however, the biological mechanisms promoting negative sequelae or recovery are not well understood (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:493 and Vital Health Stat 11 2007;248:1). Modeling intrusive trauma and post-traumatic healing in an animal model offers the opportunity to define these biological mechanisms and to inform the design of treatments. The objective of this study was to investigate the pig, Sus scrofa, as a model for intrusive trauma, using an in vitro approach. MATERIALS AND METHODS: Mandibular segments from ex vivo farm pigs were bisected and primary central incisors were prepared to either receive axial traumatic loads or to serve as non-intruded controls. A class 2 lever modeled traumatic impact to the incisors. Damage to the periodontal support in intruded and control specimens (n = 10) was evaluated through compression testing and comparison of elastic moduli. Incisor displacement was measured on X-ray images taken before and after trauma, and following compressive tests. RESULTS: Lingual x-rays showed a mean postinjury displacement of the incisor root of 3.81 ± 1.87 mm. With compression testing, the root length embedded in bone increased in traumatized and non-traumatized teeth by 2.9 mm and 0.81 mm, respectively (P = 0.03). The intrusion group Young's modulus was significantly lower than the control group (4452 vs 7704 Mpa; P = 0.05). CONCLUSION: In vitro modeling of traumatic intrusion resulted in damage to the periodontal support of central incisors and axial tooth displacement. Pig incisors offer an important model for further study of incisor trauma.

Effects of the bisphosphonate alendronate on molars of young rats after lateral luxation.

BACKGROUND AND AIM: The bisphosphonate alendronate (ALN) was employed with the aim of investigating its effects on dental and periodontal tissues after lateral luxation of developing molars. MATERIAL AND METHODS: Twenty-one-day-old Wistar rats had their second upper molars laterally luxated. Daily 2.5 mg kg(-1) ALN injections started at the day of the luxation; controls received sterile saline solution. The teeth were analyzed 7, 14, and 21 days after the procedure. On the days cited, the maxillae were fixed, decalcified, and embedded in paraffin or Spurr resin. The paraffin sections were stained with H&E, incubated for TRAP histochemistry or immunolabeled for osteopontin (OPN). Spurr ultrathin sections were examined in a transmission electron microscope. RESULTS: After 21 days, the root apex of luxated molars without ALN was wide open and disorganized and also covered by an irregular layer of cellular cementum, which was not observed in ALN-treated animals. Ankylosis sites were observed in ALN rats in both luxated and non-luxated teeth. The TRAP-positive osteoclasts were more numerous in ALN group, despite their latent ultrastructural appearance without the presence of resorption apparatus compared to controls. OPN immunolabeling revealed a thick immunopositive line in the dentin that must be resultant from the moment of the luxation, while ALN-treated specimens did not present alterations in dentin. CONCLUSION: The present findings indicate that alendronate inhibits some alterations in dentin and cementum formation induced by dental trauma.

Displacement of maxillary third molar into the lateral pharyngeal space.

Iatrogenic tooth displacement is a rare complication during extraction of impacted molars, but displacement of a maxillary third molar into the maxillary sinus, infratemporal fossa, buccal space, pterygomandibular space, and lateral pharyngeal space has been reported. Currently, 6 published reports describe third molar displacement into the lateral pharyngeal space, only 1 of which involved the loss of a maxillary third molar into this area, which occurred after an attempted self-extraction by the patient. There have been no reported cases of iatrogenic displacement of the maxillary third molar during an extraction procedure. This article describes the recovery, under general anesthesia, of a maxillary third molar from the lateral pharyngeal space after an iatrogenic displacement.

Fracture resistance of endodontically treated teeth restored with glass fiber reinforced posts and cast gold post and cores cemented with three cements.

STATEMENT OF PROBLEM: Dental fractures can occur in endodontically treated teeth restored with glass fiber reinforced posts and cast gold posts. PURPOSE: The objective of this study was to record the fracture strength of endodontically treated teeth restored with glass fiber reinforced or cast gold post and cores cemented with 3 cements. MATERIAL AND METHODS: Forty-two single-rooted premolars with standardized weakened roots were endodontically treated and allocated to 6 experimental groups (n=7) defined by the 2 factors investigated: post system and cement. Three groups were restored with glass fiber posts and resin-modified glass ionomer cement, dual-polymerizing resin cement, or chemically active autopolymerizing resin cement. The other 3 groups were restored with cast gold post and cores and the same 3 cements. The cores of the glass fiber post groups were fabricated with composite resin core material. Metal crowns were cemented on the cores in the 6 groups. The entire system was subjected to continuous compression in a universal testing machine, and fracture limit and location (cervical third, middle third, or apical third) were noted. Two-way ANOVA and the Scheffé test were used to analyze the data and compare the groups (α=.05). RESULTS: Two-way ANOVA showed significant differences in the post type (P<.001) and the cements (P<.001). The interaction between them (P<.001) was statistically significant in the fracture resistance of the endodontically treated teeth. The greatest interaction between post and cement was the glass fiber post with resin-modified glass ionomer cement, followed by the cast gold post and core with resin-modified glass ionomer cement. CONCLUSIONS: The use of a glass fiber reinforced post and resin-modified glass ionomer cement increased the fracture resistance of endodontically treated teeth.

Sodium hypochlorite accident with evaluation by cone beam computed tomography.

AIM: To show the radiographic manifestation of sodium hypochlorite after accidental injection past the apical foramen and into the soft tissues. SUMMARY: A female patient was seen for an emergency visit after suffering a sodium hypochlorite accident at her general dentist's office. The patient was seen within 1 h of the accident and was in pain associated with facial swelling. Radiographs, including a Cone Beam Computed Tomography (CBCT), and photographs were taken. Endodontic emergency treatment was initiated. The patient was reassured and given pain medication and antibiotics. Follow-up visits were scheduled over 6 days when the swelling had resolved. KEY LEARNING POINTS: • Importance of multiple radiographic images during preoperative endodontic evaluation when undertaking endodontic retreatment. • Knowledge of apical anatomy as related to surrounding structures. • Effect of sodium hypochlorite when injected in the soft tissues.

Comparison of the fracture resistance of simulated immature permanent teeth using various canal filling materials and fiber posts.

BACKGROUND: The purpose of this study was to compare the fracture resistances of immature teeth treated with MTA along with root canal obturation methods using AH Plus, MetaSEAL, MTA Fillapex sealers + lateral compaction technique, and Unicore quartz fiber posts. MATERIALS AND METHODS: Fifty single-rooted maxillary anterior teeth were divided into five groups. The crowns were dissected and root canals were enlarged. #6 Peeso reamers were allowed to protrude 1 mm. beyond the apex to simulate immature teeth. The apical 4-5 mm of each tooth was filled using Angelus white MTA. The remaining portions of canals were obturated as follows: Group 1: No backfilling (control), Group 2: AH Plus + gutta-percha, lateral compaction, Group 3: MetaSEAL + gutta-percha, lateral compaction, Group 4: MTA Fillapex + gutta-percha, lateral compaction, Group 5: UniCore Fiber posts luted using PermaFlo DC. The specimens were embedded into self-curing acrylic poured into identical cylinders which were mounted on a jig providing a 45° angle. A compressive load increasing at 1 mm min(-1) was applied and the maximum load at which fracture occurred was recorded. Statistical analysis was performed using Kruskal-Wallis and Dunn's multiple tests. RESULTS: The highest fracture resistance was obtained with Group 5 (Fiber posts) whereas Group 4 (MTA Fillapex) yielded the lowest values. The mean fracture resistance value of Group 2 (AH Plus) was significantly higher than Group 4 (MTA Fillapex) (P = 0.001). The mean fracture value of Group 5 (Fiber posts) was significantly higher than Group 2 (AH Plus), Group 3 (MetaSEAL), and Group 4 (MTA Fillapex) (P = 0.02, 0.004, and 0.0001, respectively). CONCLUSION: Within the limitations of this study, UniCore quartz fiber posts provided the highest resistance. This methodology may specifically be advantageous for teeth with arrest of development at early stages, as these teeth are more susceptible to fracture owing to their excessively weak dentinal walls.

Comparative evaluation of Ca(OH)2 plus points and Ca(OH)2 paste in apexification.

AIM: The aim of this study was to compare calcium hydroxide plus points (CHPPs) with the conventional calcium hydroxide paste (CHP) clinically and radiographically as materials used in apexification treatment. MATERIAL AND METHODS: Sixteen children, each with at least one necrotic permanent central incisor requiring apexification treatment, were selected for this study. Twenty-two selected teeth were divided into two test groups (10 CHP and 12 CHPP). The children were recalled for clinical evaluations every 3 weeks, and their radiographical evaluations were carried out every 3 months. Mann-Whitney U and Fisher's exact tests were used to evaluate the differences between the groups. RESULTS: The follow-up evaluations revealed that the success rate was 100% for CHP and 92% for CHPP. No statistically significant difference between the groups was observed (P > 0.05). CONCLUSIONS: CHPP-treated central incisors requiring apexification demonstrated good success. CHPP can be used for cases in which traditional Ca(OH)(2) apexification is indicated as it has a similar outcome with CHP.

Root fractures: the influence of type of healing and location of fracture on tooth survival rates - an analysis of 492 cases.

AIM: The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed. MATERIAL AND METHODS: Long-term survival rates were calculated using data from 492 root-fractured teeth in 432 patients. The cause of tooth loss was assessed as being the result of either pulp necrosis (including endodontic failures), new traumas or excessive mobility. The statistics used were Kaplan-Meier and the log rank method. RESULTS AND CONCLUSIONS: The location of the root fracture had a strong significant effect on tooth survival (P = 0.0001). The 10-year tooth survival of apical root fractures was 89% [95% confidence interval (CI), 78-99%], of mid-root fractures 78% (CI, 64-92%), of cervical-mid-root fractures 67% (CI, 50-85%), and of cervical fractures 33% (CI, 17-49%). The fracture-healing type offered further prognostic information. No tooth loss was observed in teeth with hard tissue fracture healing regardless of the position of the fracture. For teeth with interposition of connective tissue, the location of the fracture had a significant influence on tooth loss (P = 0.0001). For teeth with connective tissue healing, the estimated 8-year survival of apical, mid-root, and cervical-mid-root fractures were all more than 80%, whereas the estimated 8-year survival of cervical fractures was 25% (CI, 7-43%). For teeth with non-healing with interposition of granulation tissue, the location of the fracture showed a significant influence on tooth loss (P = 0.0001). The cause of tooth loss was found to be very dependent upon the location of the fracture. In conclusion, the long-term tooth survival of root fractures was strongly influenced by the type of healing and the location of the fracture.

Root canal treatment of a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement: a case report.

AIM: To present the successful endodontic management of a maxillary lateral incisor tooth with a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement. SUMMARY: A 22-year-old female was diagnosed with a skeletal Class II, Division 2 malocclusion with Class II molar and canine relationships on both sides. The treatment plan included distalization of the maxillary first molars bilaterally followed by full fixed appliance therapy. For the maxillary molar distalization, an appliance in conjunction with a miniscrew anchorage system was designed. Two months later, the patient came to the clinic with complaints of pain in the maxillary right lateral incisor region. On intraoral examination, intraoral sinus tracts were detected in the maxillary right buccal sulcus and palate. A large radiolucent lesion with a well-defined margin around the root of the maxillary right lateral incisor was seen. Root canal treatment was performed on the maxillary right lateral incisor tooth. The root canal was filled with gutta-percha and AH Plus sealer, using a lateral compaction technique. The final restoration of the tooth was completed using composite, and the tooth was reviewed after 10 months. The tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic or surgical intervention. Key learning points • This case illustrates the need to take care with miniscrews when performing orthodontic treatment, especially when the miniscrews are in close proximity to root apices. • The periradicular lesion as a result of miniscrew damage was successfully treated with root canal treatment.

Decompression of inferior alveolar nerve: case report.

Paresthesia as a result of mechanical trauma is one of the most frequent sensory disturbances of the inferior alveolar nerve. This case report describes surgical treatment for paresthesia caused by a compressive phenomenon within the mandibular canal. The cause of the compression, a broken instrument left in the patient's mouth during previous endodontic therapy, was identified during routine radiography and computed tomography. Once the foreign object was removed by surgery, the paresthesia resolved quickly. This case highlights the potential for an iatrogenic mechanical cause of paresthesia.

Treatment of multiple traumatized anterior teeth associated with an alveolar bone fracture in a 15-year-old school boy: a 2.5-year follow up.

We report a case of multiple dental traumas in a 15-year-old school boy who was hit by a stone. Clinical examinations revealed the avulsion of teeth 21, 22, and 23, an uncomplicated crown fracture of tooth 41, and a complicated crown fracture (CCF) of teeth 11, 31, and 33. An alveolar bone fracture and a root fracture in the apical third of tooth 23 were as well noted on radiographs. The avulsed teeth were replanted and rigidly splinted after an extraoral dry time of 90 min. Endodontic treatments were performed on teeth with CCFs. The dental morphology was restored using polyethylene fiber-reinforced composite resin. Endodontic obturations were performed on replanted teeth after the arrest of external root resorptions by a long-term calcium hydroxide dressing. Esthetics and function were recovered with a 2.5-year follow-up period.

Evaluation of horizontal/oblique root fractures in the palatal roots of maxillary first molars using cone-beam computed tomography: a report of three cases.

Diagnosis of root fractures is generally based on clinical and radiographic presentations. This case report aims to detect horizontal/oblique root fractures in posterior teeth using a combination of conventional radiographs and cone-beam computed tomography (CBCT). Three maxillary first molars with horizontal/oblique root fractures in the palatal roots are presented. More detailed information on root fractures can be obtained using CBCT compared with conventional radiography. As such, CBCT might be a useful complementary diagnostic method to conventional radiography in cases of suspected horizontal/oblique root fractures.

Detection of vertical root fracture using cone beam computed tomography: report of two cases.

Vertical root fractures (VRFs) often occur in endodontically treated teeth and in patients older than 40 years of age. However, VRFs in teeth without endodontic treatment are relatively uncommon. VRFs are difficult to diagnose as the symptoms are non-specific or often delayed. The most common radiographic findings are thickening of the periodontal ligament, deep, localized, vertical bone loss, and localized periradicular bone loss. The explicit feature for detecting VRFs is direct visualization of a radiolucent fracture line on radiographs. However, the fracture line can be difficult to directly visualize in conventional diagnostic methods such as periapical radiographs. If unrecognized, VRFs can lead to frustration and inappropriate endodontic treatment. The two cases reported here demonstrate that the use of cone beam computed tomography (CBCT) successfully diagnoses VRFs on teeth without representative clinical and periapical radiographic findings. The clear fracture line can be discerned from the images of CBCT. Thus, CBCT imaging is useful in rapid diagnosis of VRFs and designing of further treatment.

The effect of working length and root canal preparation technique on crack development in the apical root canal wall.

AIM: To evaluate the effects of working length and root canal preparation technique on crack development in the apical root canal wall. METHODOLOGY: Seventy extracted mandibular premolars were mounted in a resin block with simulated periodontal ligaments and divided into seven groups according to preparation technique and working length: group A, step-back preparation with stainless steel files with working length set at the apical foramen and defined as root canal length (CL); group B, same as for A, except that the working length was CL-1 mm; group C, crown-down preparation with Profile instruments followed by an apical enlargement sequence with CL as working length and group D, same as for C, except that the working length was CL-1 mm. Groups E, F and G served as controls. Groups E and F were prepared only with the crown-down sequence up to CL and CL-1 mm, respectively. Group G was left unprepared. Digital images of the apical root surface (AS) were recorded before preparation, immediately after instrumentation and after removing the apical 1 mm (AS-1 mm) and 2 mm (AS-2 mm) of the root end. RESULTS: Working length significantly affected crack development at AS (P < 0.05). Preparation technique significantly affected crack development at AS-1 mm (P < 0.05). At AS-2 mm, there was no significant difference between preparation technique and working length in terms of crack development on the canal wall. CONCLUSION: Root canal preparation alone, regardless of the technique used, can potentially generate cracks on the apical root canal wall as well as the apical surface. Working 1- mm short of the apical foramen might produce fewer cracks in the apical region.

Incidence of dentinal defects after root canal filling procedures.

AIM: To compare the incidence of dentinal defects (cracks and craze lines) after root canal preparation, lateral compaction and continuous wave compaction of gutta-percha and AH26 sealer. METHODOLOGY: Two hundred mandibular premolar teeth were divided into four groups with similar average canal diameters (n=50). One group was left untreated and served as the control. The other three groups were prepared with ProTaper rotary instruments up to size F4. After preparation, one group was left unfilled while two groups were filled with gutta-percha and AH26 using either lateral compaction or the continuous wave technique. Roots were then sectioned at 3, 6 and 9 mm from the apex and inspected under a microscope. The appearance of dentinal defects was noted as well as the minimum and mean remaining dentine thickness. Chi-square tests were performed to compare the incidence of dentinal defects between the groups (α=0.05), and Pearson correlation test was performed to check the correlation between defects and root level or remaining dentine thickness. RESULTS: The unprepared control group had no dentinal defects. The other groups exhibited significantly more defects than the unprepared group (P<0.05). There was no difference in the incidence of defects between the two filling techniques. There was no correlation between the appearance of defects and level of the root or remaining dentine thickness. CONCLUSIONS: In extracted teeth, dentinal defects were observed in roots filled with gutta-percha and AH26 using the lateral compaction and continuous wave techniques.

Foreign body in the apical portion of a root canal in a tooth with an immature apex: a case report.

AIM: To describe the successful retrieval of a foreign object located in the apical portion of an immature root canal by simple orthograde techniques, avoiding the need for surgery or intentional reimplantation. SUMMARY: A radio-opaque foreign object lodged in the apical portion of an immature root canal was discovered on radiographic examination of a patient with a complicated crown fracture. Attempts to retrieve it resulted in displacement into the periapical area. Eventually, the object was retrieved by a simple technique, followed by successful apexification, root canal filling and jacket crown placement. KEY LEARNING POINTS: Foreign bodies in root canals should be carefully evaluated to determine their nature, position, size and the degree of difficulty that may be encountered during retrieval. Patience, care and appropriate techniques may be helpful in retrieving foreign bodies and avoiding periapical surgery. Complicated crown fractures should be managed promptly, and prolonged open drainage avoided in children if the risks of foreign body impaction are to be minimized.