New formation of periodontal tissues around titanium implants in a novel dentin chamber model

PubMedID: 15877745Direct bone-to-implant contact, defined as 'osseointegration', is considered most optimal for long-term stability and survival of dental implants. However, the possibility of the formation of a tooth-like attachment apparatus around implants has also been demonstrated. The purpose of this study was to explore the formation of periodontal tissues around titanium implants using a novel and unique experimental model. After resection of the crowns of the maxillary canine teeth in nine mongrel dogs, the roots were hollowed to a depth of 5mm leaving a thin dentinal wall. Slits were prepared in the cavity wall to create passages from the chamber to the periodontal ligament area. A custom-made, titanium implant was placed into the center of each chamber. Machined, titanium plasma sprayed (TPS) and sand blasted with large grit and acid attacked (SLA) surfaces were used. A collagen barrier was placed over the submerged chamber. Following 4 months of healing, jaw sections were processed for histology. Newly formed periodontal ligament, alveolar bone, and root cementum filled the space between the implant and the wall of the chamber. Ingrown bone was neither in contact with dentin nor with the implant. Thus, an interposed soft connective tissue layer was present. Healing by fibrous encapsulation was observed around most implants. However, cellular cementum was deposited on one TPS and one SLA implant and on the dentinal walls of the chamber. This study shows a remarkable capacity for new periodontal tissue formation at a site where no such tissues ever existed. Maintenance of original periodontal tissue domains most likely prevented osseointegration of the implants. The cementum layer deposited on two implants was likely formed through cementoconductivity rather than by differentiation of periodontal ligament cells upon contact with the implant surface. Copyright © Blackwell Munksgaard 2005

Lateral ridge augmentation using a PCL-TCP scaffold in a clinically relevant but challenging micropig model

Clinical Oral Implants Research23121322-133

Comparison between Radiographic (2-dimensional and 3-dimensional) and Histologic Findings of Periapical Lesions Treated with Apical Surgery.

The aim of this study was to evaluate the concordance of 2- and 3-dimensional radiography and histopathology in the diagnosis of periapical lesions. Patients were consecutively enrolled in this study provided that preoperative periapical radiography (PR) and cone-beam computed tomographic imaging of the tooth to be treated with apical surgery were performed. The periapical lesional tissue was histologically analyzed by 2 blinded examiners. The final histologic diagnosis was compared with the radiographic assessments of 4 blinded observers. The initial study material included 62 teeth in the same number of patients. Four lesions had to be excluded during processing, resulting in a final number of 58 evaluated cases (31 women and 27 men, mean age = 55 years). The final histologic diagnosis of the periapical lesions included 55 granulomas (94.8%) and 3 cysts (5.2%). Histologic analysis of the tissue samples from the apical lesions exhibited an almost perfect agreement between the 2 experienced investigators with an overall agreement of 94.83% (kappa = 0.8011). Radiographic assessment overestimated cysts by 28.4% (cone-beam computed tomographic imaging) and 20.7% (periapical radiography), respectively. Comparing the correlation of the radiographic diagnosis of 4 observers with the final histologic diagnosis, 2-dimensional (kappa = 0.104) and 3-dimensional imaging (kappa = 0.111) provided only minimum agreement. To establish a final diagnosis of an apical radiolucency, the tissue specimen should be evaluated histologically and specified as a granuloma (with/without epithelium) or a cyst. Analysis of 2-dimensional and 3-dimensional radiographic images alike results only in a tentative diagnosis that should be confirmed with biopsy

Effects of decontamination and implant surface characteristics on re-osseointegration following treatment of peri-implantitis

PubMedID: 19298293Background: Although considerable bone fill may occur following treatment of peri-implantitis, re-osseointegration appears to be limited and unpredictable. Objectives: To evaluate the effects of various decontamination techniques and implant surface configurations on re-osseointegration of contaminated dental implants. Material and methods: Three months after tooth extraction, implants consisting of a basal part and an exchangeable intraosseous implant cylinder (EIIC) were placed in the mandibles of dogs. The EIIC was machined (M), sandblasted and acid-etched (SLA), or titanium plasma sprayed (TPS). Ligature-induced peri-implantitis was initiated 8 weeks post-implantation and lasted until bone loss reached the junction of the two implant parts. Three treatment modalities were applied: (T1) the EIIC was exchanged for a pristine EIIC; (T2) the EIIC was sprayed in situ with saline; and (T3) the EIIC was removed, cleansed outside the mouth by spraying with saline, steam-sterilized, and remounted. A collagen barrier was placed over each fixture, and 3 months later, samples were processed for histology and histomorphometry. Results: T2 revealed the highest bone-to-implant contact (BIC) level (significantly better than T1 and T3). T2 also yielded the highest bone crest level (significantly better than T1), followed by T3 (significantly better than T1). SLA showed the highest BIC level (significantly better than M), followed by TPS. There were no statistically significant differences in bone crest height between implant types. Conclusions: Both SLA implants and in situ cleansing resulted in the best re-osseointegration and bone fill of previously contaminated implants. © 2009 John Wiley & Sons AS