Clinical and patient-centered outcomes after minimally invasive non-surgical or surgical approaches for the treatment of intrabony defects: a randomized clinical trial

Background: The present study aims to compare the performance of minimally invasive non‐surgical and surgical approaches for the therapy of intrabony defects. Methods: Twenty‐nine patients who presented with intrabony defects were randomly assigned to: 1) a minimally invasive non‐surgical technique (MINST) group, or 2) minimally invasive surgical technique (MIST) group. The chair time of each therapeutic procedure was calculated. The probing depth (PD), position of the gingival margin (PGM) and relative clinical attachment level (RCAL) were evaluated at 3 and 6 months after treatments. The patient perception of discomfort/pain experienced during and after therapy and patient satisfaction regarding treatments were also evaluated. Results: Significant PD reductions, RCAL gains, and no changes in the PGM were obtained at 3 and 6 months in MINST and MIST groups (P <0.05). No differences were observed between groups at any time points (P >0.05). Patient‐oriented outcomes did not demonstrate differences between therapeutic approaches (P >0.05). Significant higher chair times were required in the MIST group than in the MINST group (P <0.05). Conclusions: Minimally invasive non‐surgical and surgical approaches were successfully used for the treatment of intrabony defects and achieved periodontal health in association with negligible morbidity and suitable patient satisfaction. However, non‐surgical therapeutic modality presented an advantage in terms of a reduction of treatment chair time.     

Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin

Objective

Streptococcus mutans, known to be a major pathogen of dental caries, is also considered to cause infective endocarditis. Its 120-kDa Cnm protein binds to type I collagen, which may be a potential virulence factor. In this study, we characterized S. mutans clinical strains focusing on the cnm gene encoding Cnm.

Design

A total of 528 S. mutans strains isolated from Japanese, Finnish, and Thai subjects were investigated. Using molecular techniques, the distribution frequency of cnm-positive strains and location of the inserted cnm were analyzed. Furthermore, isogenic mutant strains were constructed by inactivation of the cnm gene, then their biological properties of collagen-binding and glucan-binding were evaluated. Southern hybridization of the genes encoding glucan-binding proteins was also performed.

Results

The distribution frequency of cnm-positive strains from Thai subjects was 12%, similar to that previously reported for Japanese and Finnish subjects. Furthermore, the location of insertion of cnm was the same in all cnm-positive clinical isolates. As for the cnm-inactivated mutant strains constructed from 28 clinical isolates, their collagen-binding activity was negligible. In addition, glucan-binding activity in the cnm-positive clinical isolates was significantly reduced and corresponded to a lack of gbpA encoding glucan-binding protein A.

Conclusions

Our results indicate that strains with cnm genes, the most crucial factor for the collagen-binding property of S. mutans, are detectable at similar frequencies over several different geographic locations. In addition, the common properties of these strains are a high level of collagen-binding activity and tendency for a low level of glucan-binding activity.     

Prosthetic rehabilitation after osteonecrosis of the jaws due to histiocytosis X and treatment with bisphosphonates apropos of a case

Bisphosphonates are involved in the occurrence of Osteonecrosis of Jaws (ONJ), which is a complication of these treatments. This osteonecrosis concern the alveolar bone and develops generally after an oral surgery. It can however occur spontaneously without preliminary dental extraction. Other risk factors could play potentiates the risk of ONJ. This osteonecrosis results in an osseous exposure in patient treated or having been treated by bisphosphonates, without any cervico-facial irradiation. Actually, no treatment has been the proof of its effectiveness. Preventives measures of ONJ in oral cavity are the best method before, during and after administration of bisphosphonates. In this article, we present the clinical case of a patient with histiocytois treated by bisphosphonates and having developed ONJ. The selection criteria of the prosthetic rehabilitation as well as the techniques used are detailed.     

Oral carcinoma cuniculatum in a young child

From the Department of Dental Specialties, Birmingham Children's Hospital. This case study describes a rare case of oral carcinoma cuniculatum in a 7-year-old female. She presented with an enlarged mass of the anterior maxilla arising from the gingiva. An anterior maxillectomy with immediate prosthetic replacement and obturation of the residual defect were carried out. The management of this case was challenging given the rare nature of the disease, unclear etiology, the patient's young age and the mutilating effects of surgery. The treatment involved a large multidisciplinary team. The provision of obturators was particularly difficult due to poor patient compliance and the extent of surgery carried out in a growing child. Oral cancer in children under 15 years old is extremely rare and this is the youngest case of oral carcinoma cuniculatum reported in the literature.     

The pathogenesis of periodontal disease: a paradigm shift

Periodontitis is a family of related diseases that differ in etiology, natural history, disease progression and response to therapy, but have a common underlying chain of events, thatareinfluenced by disease modifiers. The clinical manifestations observed are a result of the complex interplay of these factors. The pathogenesis of human periodontitis was placed on a rational footing for the first time by Page & Schroeder in 1976 and the general principles and the overall conclusions reached in that article are still largely acceptable today. Still, an enormous amount has been learned about all aspects of human periodontitis, including its pathogenesis, since 1976. A critical evaluation of the literature regarding the complex relationship between the microbial factor, the host factor and the occurrence of a disease, might be leading us over a surge of a paradigm shift in our understanding the pathogenesis of the disease. It is well acknowledged that while the etiology of periodontitis is bacterial, the pathogenesis is inflammatory. The understanding of regulation of inflammation in periodontitis is far from complete; however, as the understanding of periodontal inflammation increases, the current understanding of the microbiology of periodontitis becomes less clear. While we think we know that bacteria initiate the disease, the role of specific bacteria is still unknown. The current knowledge of the microbiology of periodontitis is based on large cross-sectional and association studies. Periodontitis is seen as the direct consequence of bacterial invasion and is regarded as an infectious disease. It is however, not possible to draw cause and- effect inferences from these studies. One might state that the inflammation precedes the overgrowth of the bacteria. In this scenario, the initiator of the disease might be early, gram-positive colonizers that elicit a profound inflammatory response in the susceptible host. The implication of that paradigm shift outlined above is that periodontitis is an inflammatory disease, and in that case the primary target of pharmacotherapy should be the inflammation, rather than the bacteria. Still, the question to be asked and investigated is whether dampening of the inflammatory response in certain individuals susceptible to periodontitis might prevent development of disease. This is a question yet to be answered.     

Influence of drying time and temperature on bond strength of contemporary adhesives to dentine

Objectives

To evaluate the bond strength (μTBS) of self-etching adhesives in different solvent evaporation conditions.

Methods

Flat dentine surfaces from extracted human third molars were bonded with: (1) 2 two-steps self-etching adhesives (Clearfil SE Bond—CSEB); (Protect Bond—PB) and (2) 2 one-step self-etch systems (Adper Prompt L Pop—ADPLP); (Xeno III—XIII). Bonded dentine surfaces were air-dried for 5 s, 20 s, 30 s or 40 s at either 21 °C or 38 °C. Composite build-ups were constructed incrementally. After storage in water for 24 h at 37 °C, the specimens were prepared for microtensile bond strength testing. Data were analyzed by two-way ANOVA and Student–Newman–Keuls at α = 0.05.

Results

CSEB and PB performed better at warm temperature with only 20 s of air-blowing. The bond strength increased when XIII was performed at warm temperature at 40 s air-blowing. Extended air-blowing not affect the performance of ADPLP, except at 30 s air-blowing time at warm temperature.

Conclusions

The use of a warm air-dry stream seems to be a clinical tool to improve the bond strength to self-etching adhesives.