In situ Clause Samples
The "In situ" clause defines that certain work, materials, or equipment must be provided, installed, or remain at their original location rather than being moved or prefabricated elsewhere. In practice, this means that construction, assembly, or repairs are to be performed directly at the project site, such as pouring concrete foundations on location or installing fixtures without prior off-site assembly. This clause ensures that specific tasks are completed in the intended environment, which can be critical for quality control, compliance with regulations, or logistical reasons.
In situ. In situ tooth wear studies use a methodology which was originally developed for caries research and has since been adopted for use in dental erosion studies. In situ studies involve human subjects wearing intraoral appliances which carry mounted enamel and dentine slabs which have previously been sterilised or disinfected. The advantages of the in situ methodology over in vitro studies are that the influence of biological factors that influence the tooth wear process can be taken into account, such as saliva flow rate and buffering capacity; acquired salivary pellicle (diffusion limiting properties, composition, maturation and thickness); positioning in the oral cavity; physiological soft tissue movements (▇▇▇▇ et al., 2006b). The finding that in situ enamel erosion was drastically reduced by an order of 10 times compared to in vitro enamel erosion (▇▇▇▇ et al., 1998), provides an indication of the cumulative impact of these biological effects. According to the study design and hypothesis of interest, experimental tooth wear regimes may be carried out, either intra-orally or extra-orally. In order to replicate intra-oral physiology as close as possible to the erosive challenge it should ideally be carried out in situ; however the use of intra-oral erosive challenges is limited by ethical considerations, especially if the outcome of the study is substance loss. Therefore in situ/ex vivo models typically employ a cyclic study design where extra-oral acid challenges are followed by periods of intra-oral exposure to remineralising conditions (▇▇▇▇ et al., 2009). On removal from the appliance the enamel or dentine slabs are subjected to measurements of the outcome of interest.