Citric acid, but not tetracycline, improves the microscopic pattern of healing of particulate autogenous bone grafts in critical-size defects.

BACKGROUND: Bone demineralization has shown to be advantageous in autogenous onlay bone grafts and in pre-osteoblasts cultures, but such procedure has never been evaluated in particulate bone grafts. This study aimed to investigate the role of two demineralizing agents in the repair of the 8-mm critical-size defects in rats' calvaria. METHODS: Eighty adult male Wistar rats were randomly assigned to one of eight groups as follows: particulate autogenous bone demineralized with citric acid for 15 seconds (CA15), 30 seconds (CA30), or 60 seconds (CA60); particulate autogenous bone demineralized with tetracycline hydrochloride for 15 seconds (TCN15), 30 seconds (TCN30), or 60 seconds (TCN60); blood clot (NC), and non-demineralized autogenous bone (PC). The calvariae were harvested at 30 and 60 postoperative days (n = 5) for blinded histological and histometric analysis of the percentage area of newly formed bone within the defects. RESULTS: In the NC and TCN groups, bone formation was limited to the margins of the defects at 30 postoperative days, whereas complete closure was present in all the specimens from CA15 group. Both at 30 and 60 postoperative days, histomorphometry showed significant higher area of newly formed bone in specimens demineralized with CA than in those demineralized with TCN or non-demineralized (P < 0.05). TCN appeared to impair bone neoformation, as its use produced similar or inferior results compared to blood clot. CONCLUSIONS: Demineralization of particulate bone grafts with CA during 15s enhanced the regeneration of critical-size defects and may be a promising adjuvant in regenerative procedures. TCN seems to be improper for this purpose.

Bone demineralization improves onlay graft consolidation: A histological study in rat calvaria.

BACKGROUND: Previous data suggest that bone demineralization may promote bone graft consolidation as well as proliferation and differentiation of pre-osteoblasts, but the biological mechanisms involved in this process need to be clarified. This study investigated the effects of bone demineralization with citric acid (CA) and tetracycline (TCN) on the repair of onlay bone grafts. METHODS: Onlay bone grafts were performed on the calvaria of 126 Wistar rats. The contacting surfaces between bone graft and receptor bone bed were demineralized for 15, 30, and 60 seconds with TCN (50 mg/mL), or 10% CA, (pH 1), constituting the following test groups (n = 18): TCN15, TCN30, TCN60, CA15, CA30, and CA60. Control grafts (C) were performed without demineralization (n = 18). After 7, 30, and 60 days, biopsies were obtained for quantitative and qualitative histological analysis (a = 6). RESULTS: Demineralization accelerated the bone repair early from 7 days of healing. Higher percentage area of newly formed bone was observed in CA15 and TCN60 groups when compared to C in all evaluation periods (P = 0.02). At 30 days, C specimens had lower percentage of consolidated surfaces than TCN60, TCN30 and CA15 (P = 0.0015). At 60 days, CA15, CA60, and TCN60 presented bone surfaces almost completely filled by newly formed bone, against about 75% in C specimens (P = 0.0015). CONCLUSIONS: Both CA and TCN were effective in accelerating osteogenesis at the interface between bone grafts and receptor bone beds, especially when applied for 15 seconds and 60 seconds, respectively.

The concentration of citric acid as dental root conditioner influences the behavior of fibroblasts from human periodontal ligament.

OBJECTIVE: This study investigated the behavior of fibroblasts from human periodontal ligament (hPLF) cultured on dental roots subjected to different protocols of citric acid conditioning. MATERIALS AND METHODS: 32 human teeth extracted due to advanced periodontal disease provided 63 radicular fragments, which were randomly divided in groups according to the treatment given to the surface: rinsing with saline solution for 90 s (C), 10 % citric acid (CA10), or 50 % citric acid (CA50). The treatments were applied during 90 s, 120 s and 180 s (n = 9). hPLF were cultured for 24, 48 and 72 h (n = 3) on the treated samples and analyzed by scanning electron microscopy (SEM) for surface area covered by cells and dentinal tubules widening. RESULTS: Excepting group C, all the other groups showed almost complete coverage of root surface by hPLF with time. At 24 h of cell culture, the largest area of coverage was seen in the samples treated with CA10-90 (98 ± 0.89 %) at 24 h of cell culture and this difference was significant (p < 0.05) in comparison to CA10-180 (84.04 ± 5.01 %), CA50-90 (63.28 ± 12.46 %), CA50-180 (56.59 ± 8.76 %) and C (0.06 ± 0.11 %). In all the other comparisons, there was no statistically significant differences between CA10 and CA50 (p > 0.05). Cells grown on surfaces treated with CA10 were more spread and flatten than in the CA50 specimens. CONCLUSIONS: Periodontally compromised roots surfaces conditioned with 10 % citric acid for 90 s resulted in better substrate for hPLF proliferation, in initial periods of culture than 50 % citric acid. The enlargement of the dentinal tubules did not seem to be influenced by the acid concentration.

Osteogenic cells transfer improving root coverage: A randomized clinical trial.

BACKGROUND AND OBJECTIVE: The aim of this interventional, parallel-assignment, single-blinded, randomized, efficacy study was to investigate the efficacy of the treatment of gingival recessions by osteogenic cell transfer. This is the first randomized clinical trial of this nature. MATERIAL AND METHODS: Treatment of Miller class I or II gingival recessions >4 mm was randomly defined by casual sorting and performed by newly forming bone graft (NFBG) and coronally advanced flap (CAF) or subepithelial connective tissue graft (SCTG) and CAF (control). Clinical examinations were performed by a single blinded examiner at baseline and at 3, 6, and 9 months after surgery. Parameters investigated were recession height (REC), probing depth (PD), clinical attachment level, gingival bleeding index (GBI), plaque index (PlI), and keratinized gingiva width (KGW). RESULTS: Both techniques achieved similar percentage of root coverage, but NFBG was more effective in pocket depth reduction, attachment level gain, and reduction of plaque accumulation and of bleeding on probing. CONCLUSIONS: These findings suggest that the transfer of osteogenic cells by NFBG is able to improve clinical attachment level and to cover denuded roots. NFBG can be used as an alternative treatment of deep recessions (≥4 mm), where the restoration of lost periodontal tissues is intended.

Oral health impact profile of head and neck cancer patients after or before oncologic treatment: an observational analytic case-control study.

PURPOSE: The objective of this study was to investigate the impact of oral health on the quality of life of patients with head and neck cancer (HNC) before and after oncologic treatment. METHODS: Forty cancer-free individuals (Cf group) and 40 HNC patients (Hnc group) were included in this study. Hnc group was also divided into two subgroups: Hnc 1 (pre-cancer therapy, n = 20) and Hnc 2 (post-cancer therapy, n = 20). Participants were asked to complete a short form of Oral Health Impact Profile (OHIP-14). The results were statistically analyzed with the multivariate analysis of variance with post-hoc Scheffé multiple comparison. RESULTS: It was observed a moderate impact on the quality of life on HNC patients, with values on Hnc 2 group significantly higher in the functional limitation when compared to the Hnc 1 group (p < 0.05). When compared to the Cf group, the values found on Hnc group were higher on functional limitation (p < 0.01) and at the total score (p < 0.05), whereas Hnc 2 group had significant superior values on functional limitation (p < 0.01), physical pain (p < 0.05), and total score (p < 0.01) CONCLUSION: These results show that there is an oral impairment that depreciates the quality of life of patients with an experience of HNC, principally after treatment, indicating the importance of the inclusion of professionals responsible for dental and oral care with the oncologic team to monitor the oral condition of these patients.

Cyanoacrylate Adhesive as an Alternative Tool for Membrane Fixation in Guided Tissue Regeneration.

AIM: To report a well succeeded use of cyanoacrylate adhesive for fixating a resorbable membrane during a guided tissue regeneration procedure (GTR). BACKGROUND: The immobilization of membranes in GTR is essential for establishing proper environment for cell differentiation and tissue regeneration. However, some membranes are very difficult to be kept in position by sutures and its fixation by mini screws or pins may be time consuming and expensive. CASE DESCRIPTION: A 47-year-old woman presenting a vertical bone defect at the palatal aspect of the left central incisor was treated by GTR using particulate autogenous bone graft associated to a collagen membrane. The membrane was glued to the bone surrounding the defect and to the tooth surface with cyanoacrylate adhesive. The postoperative period was uneventful and 4 years later, excellent results in terms of radiographic filling of the defect and reduction of the probing depth were seen. For illustrative purposes, histological findings obtained during a previous experiment in calvaria of guinea pigs is shown, characterizing a foreign body granuloma and proving that the cyanoacrylate adhesive is a safe tool in GTR. CONCLUSION: The use of a membrane glued with cyanoacrylate to immobilize membranes in GTR is viable and safe from both technical and biological standpoints and may be advantageous for clinical and research purposes. CLINICAL SIGNIFICANCE: The alternative method for membrane fixation shown in this case report can contribute to simplify the technique in GTR procedures.