A Randomized Pilot Clinical and Microbiological Study Comparing Laser Microtextured Implants with and without Platform Switching

Minimising marginal bone loss around dental implants is of paramount importance. The success of methods such as platform switching (PS) and laser-micro-texturing (LM) are well documented. Whether or not a combination of these designs will further improve outcomes has not been studied previously. Hence, this prospective, randomized controlled single-centre pilot study compared the clinical and microbiological outcomes of implants with both PS and LM (test) to implants with only LM (control). A test and control implant were placed in thirteen patients totalling 26 implants. The primary investigated outcome was marginal bone level (MBL); secondary outcomes were peri-implant probing depths (PPD), bleeding on probing (BOP) and marginal tissue height (MTH). Additionally, the presence of five putative periodontal pathogens were assessed using real-time polymerized chain reaction. At 12 months the overall implant survival rate was 95.8%. MBL change was not found to be different between test and control at any time points, but a significant change was detected within the test implants at 6 months compared to baseline (p = 0.006). No differences were found in the secondary outcomes. Average PPD at 12 months was 2.68 ± 0.73 mm and 2.30 ± 0.46 mm and average change in MTH was 0.05 ± 0.72 mm and −0.24 ± 0.59 mm at tests and controls. No differences were reported in BOP frequency. Total periodontal pathogens count revealed no significant difference among control, test implants and adjacent tooth sites. Within the limitations of this study, it can be concluded that the addition of PS to LM implants does not significantly alter either short-term clinical outcomes or the vulnerability to pathogenic microflora colonization

Recent Outer-Shelf Foraminiferal Assemblages on the Carnarvon Ramp and Northwestern Shelf of Western Australia

The carbonate sediments of the Western Australian shelf in the Indian Ocean host diverse assemblages of benthic foraminifera. These shelf environments are dominated by the southward-flowing Leeuwin Current, which impacts near-surface circulation and influences biogeographic ranges of Indo-Pacific warm-water foraminifera. Analyses of outer-ramp to upper-slope sediments (127-264 m water depth) at four different sites (some with replicates) revealed 185 benthic species. A shift from benthic to planktonic foraminifera was accompanied by a decrease in \u27\u27larger\u27\u27 benthic foraminifera below the lowermost euphotic zone. Fisher a and proportions of buliminid and textulariid taxa increased with water depth, as miliolids and rotaliids decreased in proportion. Cluster analyses on the 125 to 250 lm and 250 to 850 lm size fractions revealed distinct assemblages, with the former distinguishing between deeper and shallower sites, and the latter distinguishing between the Carnarvon Ramp site and the three sites on the northwestern shelf (NWS). The assemblage shift with depth was likely caused by rapidly changing physical conditions in the upper thermocline. The assemblage differences between the NWS and the Carnarvon Ramp site indicate limited horizontal transport and migration rates on the outer shelf below the influence of the Leeuwin Current. Similarity in bottom-water temperature at the studied sites indicates that water mass characteristics, biogeographic history, and/or possibly diversity in benthic shelf habitats, rather than temperature and depth, are responsible for differences between the two regions

Submerged Reef Terraces in the Maldivian Archipelago (Indian Ocean)

Sea-level changes have shaped the world\u27s carbonate platform margins and continental shelves, leaving typical geomorphic imprints, such as drowned reef terraces. In this paper, we present the results of 112 scuba diving transects across seven different Maldivian atolls and one multibeam survey around Malé Island, the capital of Maldives. We report on the occurrence of drowned reef terraces down to 120 m depth. In total, we identified six levels of submerged terraces that we consider as indicative of periods of time with stable or slowly rising sea level that can be attributed either to deceleration of the last deglacial sea-level rise or to Late Quaternary sea-level highstands. We compare our dataset to the depth of reef terraces reported globally, and we discuss the reasons why common global submerged terrace levels are difficult to identify in the field record