The stability of peri-implant tissue is essential for the long-term success of dental implants. Although various types of implant connections are used, little is known about the effects of the physical mechanisms of dental implants on the stability of peri-implant tissue. This review summarizes the relevant literature to establish guidelines regarding the effects of connection type between abutments and implants in soft and hard tissues. Soft tissue seals can affect soft tissue around implants. In external connections, micromobility between the abutment and the hex component of the implant, resulting from machining tolerance, can destroy the soft tissue seal, potentially leading to microbial invasion. Internal friction connection implants induce strain on the surrounding bone via implant wall expansion that translates into masticatory force. This strain is advantageous because it increases the amount and quality of peri-implant bone. The comparison of internal and external connections, the two most commonly used connection types, reveals that internal friction has a positive influence on both soft and hard tissues.

Anatomically, the human tooth has structures both embedded within and forming part of the exterior surface of the human body. When a tooth is lost, it is often replaced by...

The Dumugol Formation (Lower Ordovician) in the southern part of the Baegunsan syncline, South Korea, contains mixed siliciclastic and carbonate ramp deposits. The ramp sediments were frequently influenced by storm events resulting in tempestites of sandstone‐mudstone couplets, bioclastic grainstones to packstones, flat‐pebble conglomerates, a skeletal lag layer and laminated calcisiltites. All tempestites are characterized by an erosive to sharp base, poor grading and a transitional upper boundary. The difference in lithology of tempestites appears to have been controlled by the nature of substrates and by proximality. For example, laminated calcisiltites have developed on the shallow carbonate ramp, flat‐pebble conglomerates are closely associated with nodular limestones on shallow and deep ramps, and thin skeletal lag layers from fossiliferous argillaceous sediments formed in a basinal setting. The stratigraphic succession of the Dumugol Formation represents an initial transgression followed by a regression. The vertical facies change records the transition from a shallow siliciclastic ramp to a deep carbonate ramp, to a basin, shallowing to a deep carbonate ramp, and to a shallow carbonate ramp. Storm effects are mostly well preserved in shallow to deep ramp deposits.

The decomposition of titanium diisopropoxide dipivaloylmethanato ͓Ti͑O-iPr͒ 2 ͑dpm͒ 2 : dpm = bis͑2,2,6,6-tetramethyl-3,5-heptanedionato͒, C 11 H 19 O 2 ͔, a Ti precursor used in metallorganic chemical vapor deposition or in atomic layer deposition processes for producing Ti-containing films, was studied in a high vacuum chamber, maintained at a pressure of 1 ϫ 10 −10 Torr, using temperature-programmed desorption ͑TPD͒. The species present on the substrate surface at different temperatures in the TPD experiments were monitored by X-ray photoelectron spectroscopy ͑XPS͒. The isopropoxy ligand is dissociated from the Ti precursor, producing acetone and isopropanol by disproportionation at 400 K and only acetone at temperatures higher than 470 K. The dissociation of the isopropoxy ligand is complete at 500 K. The dpm ligand is dissociated to give propylene and propanal at all temperatures above 470 K and the dissociation is complete at about 700 K. The XPS results indicate that titanium oxide is formed on the substrate surface at temperatures above 600 K. The other surface component is carbon, which largely originates from the t-butyl group. The formation of titanium oxide was confirmed by a separate film-deposition experiment at relatively high pressures, ϳ10 Torr, using the same Ti precursor. That is, a film deposited on Pt at high pressures showed an XPS peak for the Ti 2p state, representing titanium oxide, as the major peak when the Ti precursor was decomposed at temperatures higher than 500 K, the temperature range for dissociation of the dpm ligand.

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