Common problems errors in access opening Assist Prof

Common problems / errors in access opening Assist. Prof. Boonrat Sattapan Department of Conservative Dentistry, Faculty of Dentistry, Prince of Songkla University

Ideal access cavity • no pulp horn or roof of pulp chamber • no carious dentin or defective filling material • straight-line access • smooth wall • funnel-shape • not overextension or underextension

Common problems / errors 1. Failure to remove caries , defective restoration or unsupported tooth structure. 2 Underextension. 3 Overextension 4. Gouging / Perforation 5. Improper shape and position

Failure to remove caries, defective restoration or unsupported tooth structure Causes : • Lack of knowledge in access opening • Use inappropriate burs or instruments • Do not look field of operation carefully • Do not pay attention

Failure to remove caries, defective restoration or unsupported tooth structure Effect : ü Remaining microorganisms and contaminating during RCT ü Cannot evaluate and plan final restoration ü Filling may fracture and fall into RC ü Tooth fracture during RCT

Removal of defective restoration and unsupported tooth structure • Prevent coronal leakage • Permit straight-line access • Prevent restorative fragments from becoming lodged in RC • Improve visibility • Retain stable reference point

Remove peripheral caries before entering the pulp chamber • Reduce risk of contamination • Reduce risk of errors

Underextension • Too small • Not follow internal anatomy • Remaining of roof of pulp chamber Causes : • Lack of knowledge (anatomy of pulp chamber, access opening) • Do not have enough experiences

Underextension Effect : ü Remaining caries, defective restoration or unsupported enamel ü Remaining of roof of pulp chamber or pulp horn ü Cannot find all canal orifices ü Cannot look operative field clearly Other errors

Overextension • Too large or too deep • Gouging • Perforation Causes : • • • Lack of knowledge of PC & AO Use improper bur Misdirection of the bur Do not awear of long axis of the tooth Do not awear of the depth of PC

Overextension Effect : üremove too much tooth structure ØWeaken tooth ØChange treatment plan ØPerforation ØPrognosis

Overextension ?

Maxillry molar Mandibular molar Pa D

Causes of errors • Do not know anatomy • Do not have preoperative radiograph • Use improper / wrong burs • Misdirection of the bur • Small or calcified pulp chamber / root canal • Do not aware of the alignment of the tooth

Correction • Underextention improve • Overextention – Internal repair – Surgical repair (if perforation) Refer to endodontist

Conclusion : access opening • Knowledge of anatomy of the pulp cavity Outline of access – Shape – Size – Location – Depth • Preoperative radiograph(s) • Instruments & burs • Tooth alignment

Thank you