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.     

Oral manifestations as predictors of immune suppression in a HIV-/AIDS-infected population in south India

The objectives of the study are to evaluate the relationship between common HIV-related oral lesions and absolute CD4+ count, age, gender, and medication used and to assess the sensitivity, specificity, positive and negative predictive value of oral manifestations for low absolute CD4+ counts. HIV-positive patients, 200, from south India were selected, whose absolute CD4+ counts were determined within 2 weeks of oral examination. Sociodemographic data was obtained using a structured questionnaire. Oral manifestations were diagnosed according to presumptive criteria of EEC-clearinghouse classification (1993). Four or more concurrent oral lesions were statistically significant with low CD4+ counts <200 cells/mm3 (P = 0.005). The highest and lowest mean CD4+ cell counts were seen in individuals with linear gingival erythema (LGE; 172.5 cells/mm³) and pseudomembranous candidiasis (PC; 87 cells/mm³), respectively. Smoking, age (<35 years), and males had a positive association with oral hairy leukoplakia (OHL; P < 0.05). Patients with CD4+ counts < 200 cells/mm³ were associated with 15 times greater risk of PC and four times at greater risk for occurrence of any oral manifestation. Concurrent oral manifestations (≥4) were good predictors (80–100%) of severe immune suppression. In most resource poor countries where facilities for undertaking CD4+ counts are not available, the presence of concurrent oral manifestations may be used as an indicator of deteriorating immune status.     

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.     

Experimental induction of an incomplete hard-palate cleft in the rat

Incomplete clefts of the hard palate with soft-palate integrity are among the rarest malformations found in human beings. They appear as oval-shaped openings in the midline of the hard palate and do not extend along its whole length. The amniotic-sac-puncture technique was used to induce such clefts in 10 percent of a group of rat fetuses at day 15.3 of pregnancy. The upper jaws of such fetuses, either 17.3 or 21.3 days old, were examined in the scanning electron microscope and in serial Epon sections. At day 17.3 incomplete clefts of the hard palate were extending toward the soft palate, with the anterior portion of palatal shelves still in the vertical position and with the soft palate already fused. At day 21.3, the incomplete hard-palate clefts were smaller in both extension and width. These observations support the idea that fusion of the soft palate can occur independently of fusion in the hard-palate region.     

Effects of irradiation on grafted skin

The reaction of grafted skin to irradiation was studied in the rat and the optimum time for irradiation postoperatively was determined. There was a close correlation between the radiosensitivity and the vascularity of the graft and its recipient bed. Grafts showed different reactions depending on the time of irradiation after grafting. Those in the early hypovascular stage showed reactions similar to those of normal control skin. Severe reactions were observed in the hypervascular stage. Grafts in the late hypovascular stage showed more moderate reactions.