1. Gente M, Wenz HJ. Non-invasive method of measuring dentin resistance to the limit of the preparation depth. Deutsche Zahnärztliche Zeitschrift. 1991;46:771–3.
2. Gente M, Becker-Detert D. Studies on the specific electric resistance of the dentin of human teeth. Deutsche Zahnärztliche Zeitschrift. 1991;46:803–6.
3. Mumford JM. Path of direct current in electrical pulp testing using one coronal electrode. Br Dent J. 1959;106:23–6.
4. Purton DG, Chandler NP, Monteith BD, Qualtrough AJ. A novel instrument to determine pulp proximity. Eur J Prosthodont Rest Dent. 2009;17:30–4.
5. Eick JD, Wilko RA, Anderson CH, Sorensen SE. Scanning electron microscopy of cut tooth surfaces and identification of debris by use of the electron microprobe. J Dent Res. 1970;49(Suppl):1359–68.