Postoperative nausea and vomiting after surgery for prognathism: not only a question of patients' comfort. A placebo-controlled comparison of dolasetron and droperidol.

INTRODUCTION: The aim of this study was to evaluate the efficacy of dolasetron and droperidol (DHB) for preventing postoperative nausea and vomiting (PONV) in patients undergoing surgery for prognathism. MATERIAL AND METHODS: In a randomised, placebo-controlled, double-blind trial, the efficacy of 12.5 mg dolasetron i.v. and 1.25 mg DHB was evaluated in preventing PONV in 83 patients undergoing surgery for prognathism. Patients were allocated randomly to one of three groups: group A (n=27) received 12.5 mg dolasetron intravenously (i.v.), group B (n=27) received 1.25 mg DHB i.v. and placebo group C (n=29) received saline 0.9%. If patients complained of retching or vomiting or if patients demanded antiemetics, 20mg metoclopramide (MCP) i.v. was given. Postoperative nausea, postoperative vomiting, or nausea and vomiting was assessed in the postoperative period at 0-4 h and overall between 0 and 24 h. RESULTS: A significant reduction in the incidence of postoperative nausea and/or vomiting was observed in the dolasetron group (33%) when compared with DHB (81%) and placebo (86%) treated patients. No other significant differences between the DHB and the placebo group were found. Dolasetron (11%) significantly reduced vomiting in comparison with the DHB (52%) and placebo group (52%). The use of postoperative MCP per patient was significantly lower in the dolasetron group when compared with both other groups. Dolasetron significantly reduced the postoperative nausea and/or vomiting-score when compared with both other groups. There was no significant difference between DHB- and placebo-treated patients with regard to nausea and/or vomiting. CONCLUSION: Intravenous dolasetron (12.5 mg) is more effective than either intravenous DHB (1.25 mg) or placebo for preventing PONV after surgery for prognathism. It also was significantly superior to either DHB or placebo concerning nausea and vomiting and the need for MCP rescue medication.     

Simultaneous dental implant placement and endoscope-guided internal sinus floor elevation: 2-year post-loading outcomes

Aims: To determine whether endoscope‐guided sinus elevation procedures can be consistently used to create sufficient bone support for stable implant placement and long‐term implant success. Material and methods: Sixty‐two implants were surgically placed into 30 patients (14 men and 16 women) following internal sinus elevation without the use of graft material. Panoramic radiographs were made pre‐, post‐operative and after 24 months in order to evaluate the peri‐implant bone and maxillary sinuses. Resonance frequency analysis (RFA) was used to evaluate implant stability immediately upon placement and just before prosthesis delivery. Results: The average pre‐operative height of the maxillary alveolar bone was 8.4±2.2 mm at the premolar and 7.3±3.1 mm at the molar regions. The average bone gain was 3.5±1.8 and 4.5±1.9 mm in the premolar and molar sites, respectively. Clinical parameters and the RFA (4 and 12 weeks post‐operative) outcomes show sufficient stability (ISQ=60) of the inserted implants. Three implants failed during the healing period of 12 weeks. The overall implant success rate was 94%. After loading, no further implant failure was observed. The overall success rate after beginning of implant loading was 100%. Conclusions: Sinus floor elevation is a well‐established procedure for augmentation of the atrophic maxillary posterior region. The minimally invasive internal sinus floor elevation procedure visually guided by an endoscope helped to prevent, diagnose and manage complications such as sinus membrane perforation. The clinical outcomes of this study show that endoscope‐controlled internal sinus floor elevation combined with implant placement results in low intra operative trauma, good implant stability upon placement, low incidence of post‐operative symptoms and high success rates after 24 months of loading.     

All-ceramic systems: laboratory and clinical performance

Several all-ceramic systems have been developed in dentistry to meet the increased expectations of patients and dentists for highly aesthetic, biocompatible, and long-lasting restorations. However, early bulk fractures or chippings have led the research community to investigate the mechanical performance of the all-ceramic systems. This overview explores the current knowledge of monolithic and bilayer dental all-ceramic systems, addressing composition and processing mechanisms, laboratory and clinical performance, and possible future trends for all-ceramic materials.     

Effect of platform switching on peri-implant bone levels: a randomized clinical trial

Objective: The concept of platform switching has been introduced to implant dentistry based on observations of reduced peri‐implant bone loss. However, randomized clinical trials are still lacking. This study aimed to test the hypothesis that platform switching has a positive impact on crestal bone‐level changes. Material and methods: Two implants with diameters of 4 mm were inserted epicrestally into one side of the posterior mandibles of 25 subjects. After 3 months of submerged healing, the reentry surgery was performed. On the randomly placed test implant, an abutment 3.3 mm in diameter was mounted, resulting in a horizontal circular step of 0.35 mm (platform switching). The control implant was straight, with an abutment 4 mm in diameter. Single‐tooth crowns were cemented provisionally. All patients were monitored at short intervals over the course of 1 year. Standardized radiographs and microbiological samples from the implants' inner spaces were obtained at baseline (implant surgery), and after 3, 4, and 12 months. Results: After 1 year, the mean radiographic vertical bone loss at the test implants was 0.53±0.35 mm and at the control implants, it was 0.58±0.55 mm. The mean intraindividual difference was 0.05±0.56 mm, which is significantly <0.35 mm (P=0.0093, post hoc power 79.9%). The crestal bone‐level changes depended on time (P<0.001), but not on platform switching (P=0.4). The implants' internal spaces were contaminated by bacteria, with no significant differences in the total counts between the test and the control at any time point (P=0.98). Conclusions: The present randomized clinical trial could not confirm the hypothesis of a reduced peri‐implant bone loss at implants restored according to the concept of platform switching. To cite this article:
Enkling N, Jöhren P, Klimberg V, Bayer S, Mericske‐Stern R, Jepsen S. Effect of platform switching on peri‐implant bone levels: a randomized clinical trial.
Clin. Oral Impl. Res. 22 , 2011; 1185–1192.
doi: 10.1111/j.1600‐0501.2010.02090.x     

Influence of gaseous ozone in peri-implantitis: bactericidal efficacy and cellular response. An in vitro study using titanium and zirconia

Dental implants are prone to bacterial colonization which may result in bone destruction and implant loss. Treatments of peri-implant disease aim to reduce bacterial adherence while leaving the implant surface intact for attachment of bone-regenerating host cells. The aims of this study were to investigate the antimicrobial efficacy of gaseous ozone on bacteria adhered to various titanium and zirconia surfaces and to evaluate adhesion of osteoblast-like MG-63 cells to ozone-treated surfaces. Saliva-coated titanium (SLA and polished) and zirconia (acid etched and polished) disks served as substrates for the adherence of Streptococcus sanguinis DSM20068 and Porphyromonas gingivalis ATCC33277. The test specimens were treated with gaseous ozone (140 ppm; 33 mL/s) for 6 and 24 s. Bacteria were resuspended using ultrasonication, serially diluted and cultured. MG-63 cell adhesion was analyzed with reference to cell attachment, morphology, spreading, and proliferation. Surface topography as well as cell morphology of the test specimens were inspected by SEM. The highest bacterial adherence was found on titanium SLA whereas the other surfaces revealed 50-75% less adherent bacteria. P. gingivalis was eliminated by ozone from all surfaces within 24 s to below the detection limit (≥99.94% reduction). S. sanguinis was more resistant and showed the highest reduction on zirconia substrates (>90% reduction). Ozone treatment did not affect the surface structures of the test specimens and did not influence osteoblastic cell adhesion and proliferation negatively. Titanium (polished) and zirconia (acid etched and polished) had a lower colonization potential and may be suitable material for implant abutments. Gaseous ozone showed selective efficacy to reduce adherent bacteria on titanium and zirconia without affecting adhesion and proliferation of osteoblastic cells. This in vitro study may provide a solid basis for clinical studies on gaseous ozone treatment of peri-implantitis and revealed an essential base for sufficient tissue regeneration.