Discomfort/pain due to pocket probing at teeth and endosseous implants: a cross-sectional study.

AIM: Patients seem to feel more discomfort/pain after peri-implant probing than after periodontal probing. However, there is not one single study to address this clinical observation. Thus, this study was designed to compare discomfort/pain after peri-implant and periodontal probing. METHODS: Each of three dentists recruited and examined 20 patients each contributing one pair of one dental implant and a contralateral natural tooth. Periodontal and peri-implant probing depths (PPD) and probing attachment level (PAL) were assessed. Whether the implant or the tooth was measured first was randomly assigned. Immediately after probing, the patients scored discomfort/pain using a visual analogue scale (VAS). RESULTS: A total of 60 patients (median; lower/upper quartile: age 62.5; 47.5/69.0 years; 35 females, five smokers) were examined. With the exception of PPD at the deepest site (implants: 4.0; 3.0/5.5 mm; teeth: 3.0; 3.0/4.0 mm; P = 0.032), clinical parameters (PPD, PAL, bleeding on probing, suppuration) were well balanced between implants and teeth. Peri-implant probing (VAS: 16.4; 8.7/28.2) caused significantly (P = 0.011) more discomfort/pain than periodontal probing (9.1; 4.6/18.2). Repeated-measures analysis identified peri-implant probing causing more discomfort than periodontal probing related to the examiner (P = 0.046). CONCLUSIONS: On average, peri-implant probing caused significantly more discomfort/pain than periodontal probing.

GDF-5 and BMP-2 regulate bone cell differentiation by gene expression of MSX1, MSX2, Dlx5, and Runx2 and influence OCN gene expression in vitro.

Recombinant human growth/differentiation factor 5 (rhGDF-5) and recombinant human bone morphogenetic protein 2 (rhBMP-2), as members of the transforming growth factor Β family, influence bone formation and differentiation. This in vitro osteoblast cell culture study investigated the molecular biologic effect of these growth factors on regulator gene expression of the homebox proteins MSX1 and MSX2 as well as distal-less homebox 5 (Dlx5) and runt-related transcription factor 2 (Runx2/Cbfa1). Concerning effector genes, the messenger ribonucleic acids of osteocalcin (OCN) were quantified using a reverse transcriptase real-time polymerase chain reaction. Over a period of 15 days, osteoblasts were stimulated and analyzed at days 1, 2, 5, 10, and 15. rhGDF-5 and rhBMP-2 were applied in concentrations of 100, 500, and 1,000 ng/mL. The results showed enhanced gene expression of MSX1 and MSX2 by the lower rhGDF-5 concentration (100 ng/mL) during the first 48 hours and a marginally enhanced gene expression of Runx2 and OCN in a dose-dependent manner. The rhBMP-2 stimulation showed enhanced MSX1 and MSX2 gene expression with peaks at 24 and 240 hours; Runx2 and OCN were more highly expressed than the unstimulated control with the 100-ng/mL concentration. rhGDF-5 seems to stimulate early osteoblast differentiation and extracellular matrix production, while rhBMP-2 seems to boost early and late osteoblast differentiation. Low growth factor concentrations appeared to be more effective in terms of gene expression.