Sedative material placed over exposed or nearly exposed<unk>  1) crown 2) root 3) restoration 4)<unk>  cap 5)<unk>  chamber<unk> al dentin junction. 1) outside tooth/enamel 2) dentin tubule 3) dentin 4) odontoblastic process 5) predentin 6) odontoblast 7) capillaries 8) fibroblasts 9) nerve 10) artery/vein 11) cell-rich zone 12) cell-poor zone 13)<unk>  chamber<unk>  is a technique used in dental restorations to prevent the dental<unk>  from necrosis, after being exposed, or nearly exposed during a cavity preparation, from a traumatic injury, or by a deep cavity that reaches the center of the tooth causing the<unk>  to die. When dental caries is removed from a tooth, all or most of the infected and softened enamel and dentin are removed. This can lead to the<unk>  of the tooth either being exposed or nearly exposed which causes<unk> itis (inflammation).<unk> itis, in turn, can become irreversible, leading to pain and<unk>  necrosis, and necessitating either root canal treatment or extraction. The ultimate goal of<unk>  or stepwise caries removal is to protect a healthy dental<unk>  and avoid the need for root canal therapy. To prevent the<unk>  from deteriorating when a dental restoration gets near the<unk> , the dentist will place a small amount of a sedative dressing, such as calcium hydroxide or MTA. These materials, protect the<unk>  from noxious agents (heat, cold, bacteria) and stimulate the cell-rich zone of the<unk>  to lay down a bridge of reparative dentin. Dentin formation usually starts within 30 days of the<unk>  (there can be a delay in onset of dentin formation if the odontoblasts of the<unk>  are injured during cavity removal) and is largely completed by 130 days. Two different types of<unk>  cap are distinguished. In direct<unk> , the protective dressing is placed directly over an exposed<unk> ; and in indirect<unk> , a thin layer of softened dentin, that if removed would expose the<unk> , is left in place and the protective dressing is placed on top. A direct<unk>  cap is a one-stage procedure, whereas a stepwise caries removal is a two-stage procedure over about six months.
Pulp capping
Sinus lift
Binasal occlusion
Pneumonic device
Pocket mask
Keidel vacuum
Artefill
Asthma spacer