Agreement between 2D and 3D radiographic outcome assessment one year after periapical surgery.

AIM: To compare 2D with 3D radiography in assessing the treatment outcome 1 year after periapical surgery. METHODOLOGY: In this prospective study, periapical radiographs (PA) and cone beam computed tomography (CBCT) were performed 1 year after periapical surgery. Three calibrated observers independently evaluated the radiographs for the presence and type of periapical radiolucencies. Ratings in PA were compared to those in bucco-lingual and mesio-distal CBCT images (coronal and sagittal planes), and the ratings of the latter two were also compared between each other. Further, maximum size diameters of radiolucencies were measured on CBCT scans, and the calculated means were correlated with the types of radiolucency. Statistical analysis was completed using Friedman rank sum tests, the Wilcoxon signed rank test and the Pearson correlation coefficient. RESULTS: A total of 61 roots in 54 patients were eligible for the final assessment. On average, the intra-observer ratings were identical in 59.6% when comparing PA and CBCT (kappa 0.112 to 0.192). A very high intra-observer agreement (93.4%) was noted when comparing bucco-lingual and mesio-distal CBCT ratings (kappa 0.797 to 1). Interobserver agreement was higher for PA (68.8%) than for CBCT (bucco-lingual 45.9%, mesio-distal 47.5%), but without reaching significant differences. The calculated mean size of persistent radiolucencies in CBCT scans correlated well with the assigned types of radiolucency. CONCLUSION: CBCT images showed in nearly a third of the evaluated cases a worse situation than PA. There is a need to define criteria to assess the 'radiographic healing' in CBCT following periapical surgery.

Apical surgery: endoscopic findings at the resection level of 168 consecutively treated roots.

AIM: Endoscopic evaluation of the cut root face after root-end resection during apical surgery. METHODOLOGY: Consecutive cases undergoing apical surgery from June 2006 to May 2008 were enrolled. After root-end resection, the cut root face was inspected with a rigid endoscope and the following findings were assessed: number of canals, presence of isthmus, presence and location of craze lines/cracks, frosted dentine, and gaps between root filling material and dentine. Craze lines/cracks, frosted dentine and gaps were further correlated with the age group of the patient (<45 vs. ≥ 45 years), the type of treated tooth and the presence or absence of a post/screw. RESULTS: The final material included 168 resected roots. The highest frequency of isthmuses was found in mesial roots of mandibular first molars (88.5%). A craze line/crack was seen in 9.5%, frosted dentine in 79.8% and gaps in 83.3% at the cut root faces. Significant differences were observed for the location of the microfindings at the resected root surfaces (buccal vs. mesial vs. lingual vs. distal, P > 0.0001). Premolars had significantly more craze lines/cracks than anterior teeth (P = 0.006) and molars (P = 0.000). Frosted dentine was significantly more frequently seen in premolars (P = 0.027) and molars (P = 0.001) compared to anterior teeth. The age groups and the presence or absence of a post/screw did not significantly influence the findings. CONCLUSIONS: Frosted dentine and gaps were frequently observed with endoscopy at the resected root surfaces. The type of tooth appeared to affect the occurrence of a craze line/crack and of frosted dentine.

Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case.

AIM: To describe a method of carrying out apical surgery of a maxillary molar using ultrasonics to create a lateral sinus window into the maxillary sinus and an endoscope to enhance visibility during surgery. SUMMARY: A 37-year-old female patient presented with tenderness to percussion of the maxillary second right molar. Root canal treatment had been undertaken, and the tooth restored with a metal-ceramic crown. Radiological examination revealed an apical radiolucency in close proximity to the maxillary sinus. Apical surgery of the molar was performed through the maxillary sinus, using ultrasonics for the osteotomy, creating a window in the lateral wall of the maxillary sinus. During surgery, the lining of the sinus was exposed and elevated without perforation. The root-end was resected using a round tungsten carbide drill, and the root-end cavity was prepared with ultrasonic retrotips. Root-end filling was accomplished with MTA(®) . An endoscope was used to examine the cut root face, the prepared cavity and the root-end filling. No intraoperative or postoperative complications were observed. At the 12-month follow-up, the tooth had no clinical signs or symptoms, and the radiograph demonstrated progressing resolution of the radiolucency. KEY LEARNING POINTS: When conventional root canal retreatment cannot be performed or has failed, apical surgery may be considered, even in maxillary molars with roots in close proximity to the maxillary sinus. Ultrasonic sinus window preparation allows more control and can minimize perforation of the sinus membrane when compared with conventional rotary drilling techniques. The endoscope enhances visibility during endodontic surgery, thus improving the quality of the case.

Haemostatic effect and tissue reactions of methods and agents used for haemorrhage control in apical surgery.

AIM: To compare the haemostatic effect and tissue reactions of different agents and methods used for haemorrhage control in apical surgery. METHODOLOGY: Six standardized bone defects were prepared in the calvaria of six Burgundy rabbits. Five haemostatic modalities were tested for their haemostatic effect and tissue reactions, and were compared with untreated control defects: Expasyl + Stasis, Expasyl + Stasi + freshening of the bone defect with a bur, Spongostan, Spongostan+ epinephrine, and electro cauterization. The haemostatic effect was analysed visually and compared using Wilcoxon's signed rank test. Two groups of three animals were evaluated histologically for hard and soft tissue reactions related to the different haemostatic measures, after 3 and 12 weeks of healing respectively. RESULTS: Expasyl + Stasis and electro cauterization proved most effective in reducing bleeding (P < 0.05), but were accompanied by unfavourable tissue reactions, as indicated by the presence of necrotic bone, inflammatory cells and the absence of bone repair. These adverse tissue reactions did not recover substantially over time. However, adverse reactions were not observed when the superficial layer of bone had been removed with a rotary instrument. In contrast, Spongostan + epinephrine showed only a moderate haemostatic effect, but elicited also only mild adverse tissue reactions. CONCLUSIONS: Haemostasis in experimental bone defects is most effectively accomplished by using Expasyl + Stasis or electro cauterization. However, the bone defects should be freshened with a rotary instrument before suturing so as not to compromise healing.

The TIME technique: a new method for localized alveolar ridge augmentation prior to placement of dental implants.

Sufficient bone volume is still considered the most important prerequisite for the osseointegration of dental implants. The TIME technique (autogenous bone grafting combined with stabilization using a titanium mesh) for localized alveolar ridge augmentation was evaluated in 20 patients who had insufficient bone volumes for the primary placement of dental implants. Different clinical recordings were evaluated at TIME stage 1 (augmentation surgery) and at TIME stage 2 (reentry surgery with mesh removal and simultaneous dental implant placement). In most patients, single- or extended-tooth gaps (up to four units) were augmented with autogenous bone harvested from the chin or retromolar area. With the exception of temporary disturbances of tooth sensibility, no morbidity at the donor sites was observed. In one patient, the stabilizing titanium micromesh had to be removed prematurely because of graft infection. At the reentry surgery, the bone grafts were found to be completely incorporated in 75% of the patients. In 15% of the patients, only minimal graft resorption was observed (less than 10% of the graft volume). Subsequently, 28 implants could be placed in 19 patients. The stabilizing titanium mesh was best suited for vertical ridge augmentations. Another feature of the mesh was the excellent tissue compatibility, with little clinical or histologic inflammation, even when the mesh had become exposed.

Lateral ridge augmentation and implant placement: an experimental study evaluating implant osseointegration in different augmentation materials in the canine mandible.

The present study investigated the osseointegration of dental implants with a titanium plasma-sprayed surface (TPS) in regenerated and native bone in an experimental dog study. Initially, lateral bone defects were created in the alveolar ridge on both sides of the mandible. Two months later, lateral ridge augmentation was performed with (1) autogenous corticocancellous block grafts, (2) autogenous corticocancellous block grafts and e-PTFE membrane, (3) tricalcium phosphate particles and e-PTFE membrane, or (4) canine-derived demineralized freeze-dried bone allograft particles and e-PTFE membrane. After 4 months, membranes were removed, and non-submerged titanium implants were placed in regenerated bone (test implants) and in native bone (control implants). Two months later, the animals were sacrificed and non-decalcified orofacial sections were evaluated histometrically. All implants demonstrated high percentages (59% to 75%) of bone-to-implant contact, with no significant differences across the various treatment groups. The different grafting techniques did not significantly influence the location of first bone-to-implant contact and the horizontal bone width at the most coronal bone level.

Evaluation of a prototype trilayer membrane (PTLM) for lateral ridge augmentation: an experimental study in the canine mandible.

The objective of this animal study was to evaluate a biodegradable/bioresorbable prototype trilayer membrane (PTLM) consisting of two collagen layers and an internal polylactide layer for lateral ridge augmentation in conjunction with two different bone grafting materials: particulate autograft or deproteinized bovine bone mineral (DBBM). In four mongrel dogs, two lateral bone defects per side were created in the mandible. The four defects per dog were randomly subjected to the following grafting treatments 3 months later: 1. PTLM+DBBM, 2. PTLM+particulate autograft, 3. ePTFE membrane+DBBM, 4. ePTFE membrane+particulate autograft. After a healing period of 4 1/2 months, the dogs were sacrificed for histological and histomorphometrical analysis. Percentage calculations for areas showing bone regeneration within the former defect outline were 56.8% for PTLM+DBBM, 85.2% for PTLM+autograft, 52.3% for ePTFE+DBBM, and 96.9% for ePTFE+autograft (differences between autograft and DBBM sites were significant at P<0.01 to P<0.05). Measurements of ridge enlargement (horizontal bone gain) were also significantly better for autograft+ePTFE sites compared to the other three grafting treatments. Histology demonstrated for most PTLM sites a moderate infiltration of lymphocytes and plasma cells adjacent to empty spaces corresponding to polylactide fragments. In addition, these reactions appeared to provoke subsequent resorption of newly formed bone. No such findings were seen in ePTFE sites. The tested prototype membrane cannot be recommended for clinical application.

Autotransplantation for treatment of regional odontodysplasia. Case report with 6-year follow-up.

Regional odontodysplasia is an uncommon dental malformation with characteristic clinical and radiographic findings. Affected teeth appear discolored with irregularly shaped surfaces. Radiographically wide pulp chambers and thin poorly defined hard tissue outlines are typical features. This report describes a 9-year-old girl with recurrent and recalcitrant periapical infections as a result of unilateral mandibular odontodysplasia. With a 6-year follow-up, this is the longest documented case of regional odontodysplasia treated by tooth autotransplantation.

Rationale for the application of the GTR principle using a barrier membrane in endodontic surgery: a proposal of classification and literature review.

Periradicular surgery has become an established treatment option in endodontic surgery. The major objective of this surgery is to obtain periradicular tissue regeneration, including the formation of a new attachment apparatus, by exclusion of any potentially noxious agent within the physical confines of the affected root. However, in a substantial number of cases, the endodontic lesion has a concomitant marginal periodontal lesion that may complicate the healing success. In periodontology, the guided tissue regeneration (GTR) principle using a barrier membrane has been extensively studied and successfully used, and thus may become an adjunct in endodontic surgery. This article presents a classification system of endodontic and periodontal lesions with respect to the application of the membrane technique and reviews the pertinent literature based upon this classification system.

Implant placement and simultaneous peri-implant bone grafting using a micro titanium mesh for graft stabilization.

This article reports the surgical technique and outcome of simultaneous bone grafting and implant placement. A new treatment philosophy different than the principle of guided bone regeneration is presented. The technique is characterized by grafting autogenous bone into a peri-implant bone defect rather than by regenerating bone in a secluded space. Stabilization of the autogenous bone graft is achieved with a micro titanium mesh. The study sample comprised 10 implant sites in six patients. All sites were successfully treated, and postoperative healing was uneventful. The autogenous bone grafts demonstrated perfect integration upon reevaluation when the implants were recovered. The micro titanium mesh proved to be highly biocompatible, exhibited excellent mechanical properties, and avoided graft displacement and contour collapse.

Anterior maxillary supernumerary teeth: a clinical and radiographic study.

Clinical records and radiographs of 90 patients with 113 anterior maxillary supernumerary teeth (mesiodens) have been evaluated. Although uncommon, mesiodentes are the most frequent supernumerary teeth and may disturb the eruption and/or position of the adjacent permanent incisors. Clinical and radiographic examination may disclose the number, direction and location of mesiodentes and their effects on neighbouring teeth. In the present study the majority of the supernumerary teeth lay palatal to the central incisors. Complete or partial eruption of a mesiodens was rare, hence the importance of radiographs to locate supernumerary teeth in the premaxilla. Pathological findings included the formation of dentigerous cysts in three patients and complete ossification of the pericoronal space with resorption of the crown of the mesiodentes in eight cases. Retention and malposition of the adjacent permanent incisors occurred in 39 and 24 cases, respectively.

Developmental disturbances of permanent teeth following trauma to the primary dentition.

The topographic relationship of the apices of the primary teeth to the permanent tooth germs explains the potential for possible developmental disturbances of the permanent teeth after injuries to their predecessors. The anatomical, histologic and clinical aspects of permanent tooth malformation following trauma to the primary teeth are described. One hundred and fourteen children with originally 255 traumatized primary teeth have been re-examined (with an average period of 5.1 years after the trauma) to assess any developmental disturbances of the corresponding permanent teeth. Twenty-three per cent of partially or completely erupted permanent teeth showed developmental disturbances. The most frequent malformation was enamel hypoplasia including enamel discoloration and/or enamel defects. The highest prevalence of developmental disturbances of permanent teeth was found after intrusive injuries of primary teeth.

[Deciduous tooth intrusions and the odontogenesis of the permanent teeth. Developmental disorders of the permanent teeth following intrusion injuries to the deciduous teeth]. / Milchzahnintrusionen und Odontogenese der Bleibenden Zähne. Entwicklungsstörungen bleibender Zähne nach Intrusionsverletzungen von Milchzähnen.

Traumata to primary teeth occur very often in small children. The highest prevalence of developmental disturbances of permanent teeth after trauma to their predecessors has been recorded after intrusive injuries of primary teeth. In the present survey 47% of the recalled children had such developmental disturbances. The majority of developmental disturbances consisted of enamel hypoplasia (59%) which included discoloration, defects or a combination of both. In some cases the clinical feature of enamel defects could be diagnosed radiographically before tooth eruption. However, the total number of all enamel discolorations was to be detected after complete tooth eruption only. The so-called pre-eruptive calciotraumatic lines on radiographs corresponded clinically to circular enamel defects or crown dilacerations. Generally, a high correlation was found between the degree of intrusion (of the primary tooth) and the frequency and severity of developmental disturbance (of the permanent tooth). No correlation was found, however, concerning the treatment of intruded primary teeth and the occurrence of developmental disturbances. Whether intruded primary teeth were removed immediately or left to spontaneous re-eruption did not affect the incidence and type of developmental disturbances.

[Temporomandibular joint fractures in children. A clinical and radiological follow-up in 30 patients]. / Kiefergelenkfrakturen bei Kindern. Eine klinische und radiologische Nachuntersuchung bei 30 Patienten.

Disturbances of facial growth, occlusion and temporomandibular joint function respectively are all possible sequelae of condylar fractures in children. In this study 30 children (age at accident from 9 months to 14 years, mean 6 years and 9 months) were reexamined who had sustained conservatively treated condylar fractures. Dysfunction and disturbances within the stomathognathic system were assessed by a clinical and radiographic examination. The mean interval between the accident and the follow-up study was 4 years and 11 months. The maximal interincisive distance was always better than 35 mm. The "en face" analysis revealed 6 cases with an inclined occlusion plane referring to the horizontal plane. Only 3 patients, all with bilateral condylar fractures, showed a restricted mandibular mobility. Remodelling of the condylar head was very good in 77% of the cases. In the frontal plane, 21% of the unilateral cases and 33% of the bilateral cases respectively had a persistent medial inclination of the condyle. The measured difference in length of the processus articularis showed the highest correlation to the previous condylar fracture. The radiological evaluation after Ricketts (1960) and Mulick (1965) to assess facial asymmetry revealed six cases (20%) with a relevant angle difference of more than 5 degrees.