DENTAL HARD TISSUE DESTRUCTION 99 



to begin with), and (c) the pathways of the dentinal tubules, which 

 contain protoplasmatic extensions from the pulpal odontoblasts and 

 may be subject to secondary calcifications, decalcifications, and 

 bacterial invasion as a late feature of caries. 



As will be noted below, these manifestations of tooth destruction 

 in caries are significantly different from those occurring in dental 

 erosion in vivo and in vitro, on the one hand, and those occurring 

 during postmortem destruction of the teeth, on the other. 



Dental Erosion 



There are numerous reports in the literature regarding erosion of 

 teeth caused bv various chemical agents with and without concur- 

 rent abrasion caused by mechanical friction. 



Stafne and Lovestedt ( 1947 ) have observed a number of cases in 

 which dissolution of tooth substance was caused bv various kinds of 

 acids, juices, soft drinks, etc. Similar eftects have been observed as 

 a result of certain medicaments (James and Parfitt, 1953), thera- 

 peutic use of dilute hydrochloric acid (Stafne, 1933), general hy- 

 drogen ion concentration (Elsburv, 1952), long-continued vomiting 

 accompanying obstipation (Bargen and Austin, 1936), diabetes 

 insipidus (Finch, 1957), excessive consumption of acidified candies 

 (West and Judy, 1938), miscellaneous natural juices (Gortner and 

 Kenigsberg, 1952), acidified beverages (McClure, 1943; McCay 

 and Will, 1949; Restarski et ah, 1945; Gortner et al, 1945), various 

 types of fruit drinks (Miller, 1950; Holloway et al., 1958), dietary 

 oxalate (Gortner et al., 1946), citrate and lactate (McClure and 

 Ruzicka, 1946). These reports also contain observations on partial 

 control of such erosions by various buffering agents, fluoride, etc. 

 (Restarski et al., 1945; Holloway et al., 1958) as well as many cross 

 references to other literature not cited here. 



The degree to which abrasive action is involved in the progress 

 of erosion-like lesions of the teeth is not fully understood. As a rule 

 the lesions referred to above have the appearance of rather diffuse 

 dissolution, whereas tvpical abrasion and atypical erosion (idio- 

 pathic, see below) mav ha\'e a more definitive pattern depending 

 upon the location of the frictional and or chemical influences. 



