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.

Exercise capacity in athletes with mouthguards.

The objective of this study was to determine the effect of wearing a mouthguard on maximal exercise capacity and cardiopulmonary parameters at peak workload, and to assess the athletes' attitudes toward wearing a mouthguard. Thirteen volunteer male athletes (18 to 27 years old) were interviewed before and after delivery of a custom-made laminated mouthguard. A visual analogue scale (VAS, 0 - 100 mm) was used for judgment of interference with breathing, speaking, concentration and athletic performance. In addition, the athletes were subjected to a cardiorespiratory examination on a cycle ergometer with and without mouthguards. Subjectively, the athletes rated the mean interference with performance to be 37 mm VAS at the beginning of the study. Mean scores of impairment decreased to 23 mm VAS (p = 0.081) after wearing the mouthguard for four weeks, and further improved to 12 mm VAS (p < 0.001) after the test on the cycle ergometer. Objectively, the maximum workload during spiroergometry was even slightly elevated during exercise with the mouthguard (330.2 W) compared to exercise without the mouthguard (314.5 W). Peak minute ventilation and oxygen uptake were not different during exercise with and without the mouthguard. The present study demonstrated that a custom-made mouthguard does not significantly affect or reduce maximum exercise performance of athletes.

Intentional replantation for the management of maxillary sinusitis.

AIM: To present a case that emphasizes the importance of the use of intentional replantation as a technique to successfully treat a periapical lesion and an odontogenic maxillary sinusitis through the alveolus at the same time. SUMMARY: This case report presents a patient with odontogenic maxillary sinusitis secondary to periapical disease of a maxillary molar that had previously received root canal treatment. The molar was extracted, with drainage and rinsing of the maxillary sinus. The apices were resected extra-orally, the retrograde cavities prepared with ultrasound and retrograde fillings of silver amalgam placed. The tooth was then replanted. After 2 years, the patient was asymptomatic, periapical radiography showed no evidence of root resorption and computed tomography scanning demonstrated the resolution of maxillary sinusitis. KEY LEARNING POINTS: *When root canal treatment or periapical surgery cannot be undertaken or has failed, intentional replantation may be considered. *This alternative treatment may be predictable in certain cases.

Changes of periodontal parameters following apical surgery: a prospective clinical study of three incision techniques.

AIM: To evaluate periodontal changes following apical surgery, and to relate changes to the type of incision and to the type of restoration present at the gingival margin (GM). METHODOLOGY: Periodontal parameters [probing depth (PD), level of GM and clinical attachment, plaque and bleeding indices] were recorded at baseline and 1 year following apical surgery. The periodontal changes were calculated and assessed with respect to the incision technique (intrasulcular incision, papilla base incision and submarginal incision), as well as to the presence and type of a restoration margin in contact with the gingiva. RESULTS: One hundred and eighty-four teeth could be evaluated. No significant differences between the three incision techniques were found regarding changes in PDs and plaque index over time. However, significant differences between the intrasulcular and submarginal incisions were found for changes in levels of GM and clinical attachment. For example, with the intrasulcular incision, there was a mean recession of 0.42 mm at buccal sites, whereas using the submarginal incision there was a gain of 0.05 mm. No statistically significant influence could be demonstrated for the presence and type of restoration margins, or the smoking habit of the patient. CONCLUSION: The type of incision was found to affect changes significantly in periodontal parameters within an observation period of 1 year following apical surgery, whereas the restoration margin and smoking habit did not prove to have any significant effect.

Haemostatic agents used in periradicular surgery: an experimental study of their efficacy and tissue reactions.

AIM: To evaluate the haemostatic efficacy and the histologic tissue responses after the application of different haemostatic agents used in periradicular surgery. METHODOLOGY: The study was conducted in the calvarium of six rabbits. Standardized bone defects (diameter 4 mm) were trephined, and different haemostatic agents were applied and compared with control defects: bone wax (left for 10 min), Stasis (ferric sulphate, left for 5 s), Expasyl (aluminium chloride, left for 2 min and left permanently in situ), and a combination of Expasyl (2 min) and Stasis (5 s). The sites were photographed before the application and after the removal of the haemostatic agents. Three independent examiners judged the initial and final bleeding (on the photographs) using a bleeding score for each site and treatment. The results were compared using Wilcoxon's signed rank test. For the histologic analysis, three animals were killed after 3 weeks and three animals after 12 weeks. Transverse, nondecalcified sections were stained with combined basic fuchsin and toluidine blue for descriptive histology. RESULTS: The most efficient haemorrhage control was provided by Expasyl in combination with Stasis and by Expasyl alone, whereas bone wax had the weakest bleeding reduction effect. The histologic analysis after 3 weeks demonstrated an inflammatory and foreign body tissue response towards all haemostatic agents. At 12 weeks, this tissue response was less pronounced but still present in sites treated with bone wax or Expasyl. In general, the inflammatory tissue reactions were limited to the bone defects, and never extended into the surrounding tissues. CONCLUSIONS: Expasyl alone or in combination with Stasis appeared to be the most efficient of tested agents to control the bleeding within the bony defects created in a rabbit calvarium model.

Frequency and type of canal isthmuses in first molars detected by endoscopic inspection during periradicular surgery.

AIM: To analyse the occurrence of canal isthmuses in molars following root-end resection. METHODOLOGY: The material consisted of 56 mandibular and 32 maxillary first molars subjected to periradicular surgery. Based on radiographic, clinical, as well as intraoperative status, only roots with associated pathological lesions were treated. In total, 124 roots were resected (80 mandibular and 44 maxillary molar roots). The cut root faces were inspected with a rigid endoscope following apical root-end resection. The number of canals as well as the presence and type of canal isthmuses were recorded. RESULTS: In maxillary first molars, 76% of resected mesio-buccal roots had two canals and an isthmus, 10% had two canals but no isthmus, and 14% had a single canal. All disto-buccal and palatal roots had one canal. In mandibular first molars, 83% of mesial roots had two canals with an isthmus. In 11%, two canals but no isthmus were present, and 6% demonstrated a single canal. Sixty-four per cent of distal roots had a single canal and 36% had two canals with an isthmus. CONCLUSIONS: This clinical study during periradicular surgery and intraoperative endoscopic examination of first permanent molars found a high frequency of canal isthmuses at the resection level. Endoscopic inspection also demonstrated that none of the isthmuses were filled, emphasizing the difficulty of orthograde instrumentation and root filling of canal isthmuses.

Diagnostic accuracy of endoscopy in periradicular surgery - a comparison with scanning electron microscopy.

AIM: To compare the accuracy of endoscopic diagnostics with the scanning electron microscope (SEM) in evaluating elements of periradicular surgery. METHODOLOGY: The material consisted of 22 extracted human molars, which were subjected to the following treatments: orthograde root-canal obturation, root-end resection and root-end cavity preparation with diamond-coated sonic microtips. After each step, the cut root face was inspected with an endoscope, and subsequently, the roots were duplicated for SEM evaluation. Endoscope findings were compared to those obtained with SEM serving as the 'gold standard' with a blinded observer. The presence of the following structures was assessed including specificity and sensitivity: isthmuses, accessory canals, obturation gaps, microfractures and chipping of cavity margins. RESULTS: The specificity and sensitivity of the identification of isthmuses or accessory canals was 100% each for the endoscope compared to SEM. The sensitivity of identification of obturation gaps, crack formation or chipping ranged between 73 and 95% (except intradentine cracks with only 36% sensitivity). The specificity of the same parameters ranged between 77 and 100% for the endoscope compared to SEM. CONCLUSIONS: With the exception of intradentine cracks, the endoscope accurately identified microstructures following root-end resection and root-end preparation. The endoscope could be considered for use during intraoperative diagnostics in periradicular surgery.

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.

Splinting of traumatized teeth with a new device: TTS (Titanium Trauma Splint).

Displacement injuries of permanent teeth are an increasing emergency in the dental office. Children and adolescents are particularly prone to dental trauma due to participation in risky activities. Repositioning or replantation with subsequent stabilization by a dental splint is the standard of care for most displaced or avulsed permanent teeth. Non-rigid fixation allowing physiologic tooth mobility has been shown to be desirable for periodontal healing. A flexible splint of short duration appears to reduce the risk of dentoalveolar ankylosis or external replacement resorption. Different splinting techniques are currently recommended for stabilization of repositioned or replanted teeth, including a wire-composite splint, an orthodontic bracket splint or a resin splint. Each splinting option has its specific advantages and shortcomings. This paper describes a new splinting technique which offers improved comfort and handling to the patient and dentist alike.

Periradicular surgery of molars: a prospective clinical study with a one-year follow-up.

AIM: The purpose of this prospective clinical study was to evaluate the outcome of periradicular surgery of molars after one year. METHODOLOGY: The material consisted of 25 molars with 39 roots demonstrating periradicular lesions of endodontic origin. Surgical treatment included root-end resection, root-end preparation with sonic microtips, and root-end filling with Super-EBA cement. At the one-year follow-up examination, healing was evaluated clinically and radiographically. Healing was assigned to three categories: (i) success (ii) improvement, and (iii) failure using well defined criteria. RESULTS: Eighty-eight per cent of the surgically treated molars showed successful healing. In 8%, the healing was rated as improved and only 4% were failures. CONCLUSIONS: The outcome of the present study and data of recently published studies show that periradicular surgery may result in a predictable treatment outcome in molars with persistent periradicular lesions.

Treatment of replacement resorption with Emdogain--preliminary results after 10 months.

Ankylosis of traumatized teeth in children and adolescents may inhibit further development and growth of the corresponding jawbone. Therefore, ankylosed teeth should be removed. As an alternative treatment option to autotransplantation of a premolar, intentional replantation using Emdogain may be considered, provided the ankylosis is detected at an early stage or has only affected a small area of the root. Eleven ankylosed teeth presenting with replacement resorption were treated as follows: after tooth extraction, the root canal was treated extraorally and obturated by retrograde insertion of a titanium post. Emdogain was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. During a mean follow-up period of 6.3 months, no signs of recurrence of ankylosis were noted. The horizontally and vertically measured Periotest scores were identical to those obtained on the adjacent teeth. These results suggest that intentional replantation using Emdogain may prevent or delay ankylosis of these replanted teeth.

Decoronation of an ankylosed tooth for preservation of alveolar bone prior to implant placement.

A 12-year-old patient sustained avulsions of both permanent maxillary central incisors. Subsequently, both teeth developed replacement resorption. The left incisor was extracted alio loco. The right incisor was treated by decoronation (removal of crown and pulp, but preservation of the root substance). Comparison of both sites demonstrated complete preservation of the height and width of the alveolar bone at the decoronation site, whereas the tooth extraction site showed considerable bone loss. In addition, some vertical bone apposition was found on top of the decoronated root. Decoronation is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It must be considered as a treatment option for teeth affected by replacement resorption if tooth transplantation is not feasible.

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.

Lateral ridge augmentation using different bone fillers and barrier membrane application. A histologic and histomorphometric pilot study in the canine mandible.

Lateral ridge augmentation has become a standard treatment option to enhance the bone volume of deficient recipient sites prior to implant placement. In order to avoid harvesting an autograft and thereby eliminating additional surgical procedures and risks, bone grafting materials and substitutes are alternative filler materials to be used for ridge augmentation. Before clinical recommendations can be made, such materials must be extensively studied in experimental models simulating relevant clinical situations. The present pilot study was conducted in three dogs. Different grafting procedures were evaluated for augmentation of lateral, extended (8 x 10 x 14 mm) and chronic bone defects in the mandibular alveolar ridge. Experimental sites received tricalcium phosphate (TCP) granules or demineralized freeze-dried bone allograft (DFDBA) particles. Barrier membranes (ePTFE) were placed for graft protection. These approaches were compared to ridge augmentation using autogenous cortico-cancellous block grafts, either with or without ePTFE-membrane application. After a healing period of six months, the sites were analyzed histologically and histomorphometrically. Autografted sites with membrane protection showed excellent healing results with a well-preserved ridge profile, whereas non-protected block grafts underwent bucco-crestal resorption, clearly limiting the treatment outcome. The tested alloplastic (TCP) and allogenic (DFDBA) filler materials presented inconsistent findings with sometimes encapsulation of particles in connective tissue, thereby reducing the crestal bone width. The present pilot study supports the use of autografts with barrier membranes for lateral ridge augmentation of extended alveolar bone defects.