Comparison of anesthetic efficacy of 2 and 4 % articaine in inferior alveolar nerve block for tooth extraction-a double-blinded randomized clinical trial.

OBJECTIVES: The purpose of this clinical prospective, randomized, double-blind trial was to compare the anesthetic efficacy of 2 % articaine and 4 % articaine in inferior alveolar nerve block anesthesia for extraction of mandibular teeth. MATERIALS AND METHODS: In 95 patients, 105 lower molar and premolar teeth were extracted after intraoral inferior alveolar nerve block. In 53 cases, 2 % articaine (group I) and, in 52 cases, 4 % articaine (group II) was administered. The primary objective was to analyze the differences of anesthetic effects between the two groups (complete/sufficient vs. insufficient/none). Furthermore, differences in pulpal anesthesia (onset and depth, examined with pulp vitality tester (min)), as well as in length of soft tissue anesthesia (min), were evaluated. Additionally, the need of a second injection, pain while injecting (numeric rating scale (NRS)), pain during treatment (NRS), pain after treatment (NRS), and other possible complications (excessive pain, bleeding events, prolonged deafness) were analyzed. RESULTS: Anesthesia was sufficient for dental extractions in both groups without significant differences (p = 0.201). The onset of anesthesia did not differ significantly (p = 0.297). A significantly shorter duration of soft tissue anesthesia was seen in group I (2.9 vs. 4 h; p < 0.001). There was no significant difference in the need for a second injection (p = 0.359), in injection pain (p = 0.386), as well as in pain during (p = 0.287) or after treatment (p = 0.121). In both groups, no complications were seen. CONCLUSIONS: The local anesthetic effect of the 4 % articaine solution is not significantly better when compared to 2 % articaine. CLINICAL RELEVANCE: For mandibular tooth extraction, articaine 2 % may be used as alternative as well.

Influence of a collagen membrane and recombinant platelet-derived growth factor on vertical bone augmentation in implant-fixed deproteinized bovine bone--animal pilot study.

OBJECTIVES: Combinations of bone substitute block materials with membrane techniques as well as with growth factors are possible options to enhance the prognosis of vertical bone augmentation. Therefore, the aim of the pilot study was to compare the influence of a collagen membrane and a signal protein (rhPDGF-BB) on vertical bone augmentation with a stable fixed block material (deproteinized bovine bone [DBB]). MATERIALS AND METHODS: In 12 rabbits, a DBB-block was implant-fixed on the tibia in a split-leg-design. Included were: DBB only (control), DBB + collagen membrane (test), DBB + rhPDGF-BB (test) and DBB + rhPDGF-BB + collagen membrane (test). 24 samples were examined after 3 (n = 12) and 6 weeks (n = 12). Calculated parameters were new bone area (NBA;%), new vertical bone height (VBH; mm). Due to the pilot character of this study, single values are shown descriptively only. RESULTS: After 3 weeks, there were constant higher NBA values in the rhPDGF-BB-group without membrane (NBA (%) DBB: 30/16/4; DBB + membrane: 25/17/7, DBB + rhPDGF-BB: 40/33/34, DBB + rhPDGF-BB + membrane: 0/30/16; VBH (mm) DBB: 1.2/1.2/1, DBB + membrane: 0.7/0.9/1, DBB + rhPDGF-BB: 0.7/0.9/1, DBB + rhPDGF-BB + membrane: 0/1.1/1). After 6 weeks, both membrane groups showed a constant higher NBA and VBH independent to the use of rhPDGF-BB (NBA DBB: 3/0/5, DBB + membrane: 20/35/31, DBB + rhPDGF-BB: 5/8/4, DBB + rhPDGF-BB + membrane: 31/35/40; VBH DBB: 0.3/0.3/0.6, DBB + membrane: 1.6/2.4/2.1, DBB + rhPDGF-BB: 0.4/0.7/0.8, DBB + rhPDGF-BB + membrane: 1.8/2/1.8). CONCLUSIONS: For vertical augmentation, the addition of rhPDGF-BB to DBB-blocks may increase early bone growth. In the later phase, the use of a collagen membrane enhances new bone volume and height to a significant greater extend. Even if the results are higher than those in the non-membrane groups, the low gain of bone after the short time periods still needs improvement.

Dexrazoxane shows cytoprotective effects in zoledronic acid-treated human cells in vitro and in the rabbit tibia model in vivo.

INTRODUCTION: Bisphosphonates are important and effective drugs in oncology and osteoporosis therapy. They accumulate in the bone matrix becoming released and active by bone resorption. This leads to effective inhibition of tumor cells and bone degradation. A side effect of bisphosphonates similar to other drugs like denosumab is osteonecrosis of the jaws (ONJ). This problem mostly occurs after tooth extraction. We studied the cytoprotectant dexrazoxane known from anthracycline chemotherapy for cytoprotection in nitrogen-containing bisphosphonate treated cells and in the rabbit tibia model to evaluate a possible value in ONJ management. MATERIALS & METHODS: Human osteoblasts (HOB) P2 cells and Human ginigiva fibroblasts (HGF) P2 cells were treated with zoledronic acid (50 µmol/L) and the cytoprotectant dexrazoxane (600 µmol/L). Analysis included cell viability testing with MTT assay and morphology analysis using CellTracker™ Green CMFDA. A biomaterial carrier (Bio-Oss Collagen) was implanted in the rabbit tibia of 6 female chinchilla bastard rabbits on both sides with drill hole defects (d: 3.2mm). Implants were loaded with 25 nmol zoledronic acid, with and without 300 nmol dexrazoxane and unloaded in a control group. Analysis included histological examination of undecalcified samples with toloudine blue staining after 10 days. RESULTS: In vitro experiments showed a significantly higher MTT activity in cells treated with zoledronic acid together with dexrazoxane compared to the same cells treated with the bisphosphonate alone in t-test (HOB: p=0.0003; HGF: p below 0.0001) and one-way ANOVA. Cell morphology changes were consistent with these results. In vivo results showed newly formed bone trabeculae directly growing towards the implanted hydroxylapatite particles and cortical bone interface resorption activities in the control and the experimental group only. CONCLUSION: The study suggests a possible value of this patented technology for ONJ therapy and prevention with local or systemic application.