Knowledge of the size, morphology and variation of the root canals of a primary tooth is useful in visualizing the pulp cavity during treatment. The purpose of this study was to determine the length of the root canals of primary maxillary incisors and mandibular molars, and to visually examine the root canal anatomy using a clearing technique and a dissecting microscope. Forty primary teeth with mild to moderate caries without gross incidence of root resorption were selected from a group of extracted teeth. The teeth were cleansed and access to the pulp chamber was prepared. For molar teeth, the length from the floor of the pulp chamber to the occlusal surface was recorded. The lengths of the root canals of maxillary incisors and mandibular molars were measured using root canal files. Subsequently, the teeth were divided into two groups. Croup I consisted of teeth cleared and injected with ink to demonstrate pulpal anatomy using the clearing technique. Teeth in Croup II were sectioned longitudinally or transversely for stereoscope examination. Both Groups I and II were examined and photographed using a dissecting microscope. The length from the occlusal surface to the pulp floor was 5.79 ± 0.63 (mean = ± SD mm). The lengths of the root canals will be presented. The variations observed in the root canals of the mandibular molars include fine connecting intercanal branches, accessory canals and apical ramifications. The variations found in the length of the root canals-emphasize the need for accurate preoperative periapical radiographs. The findings of this study support the technical difficulty of performing a successful pulpectomy of a primary molar and provide additional evidence indicating that pulp treatment of primary molars may be a complex undertaking.
Saudi Dental Journal 1992;4(SI)-Abstr.71:p72.

Following necrosis of the pulp caused by dental caries or trauma, spread of infection occurs through the root canal and into the periapical region. This periapical infection may lead to formation of periapical granuloma, radicular cyst or acute periapical abscess. Periapical or periradicular infection of the primary teeth may lead to injury of the permanent successors, which can vary from hypocalcification of enamel, to arrest of permanent tooth development, or dentigerous cyst formation.

The purpose of this study was to examine and describe periapical abscess and granuloma in primary teeth using radiographic, stereoscopic, histopathologic and scanning microscopic techniques.

Twenty carious non-restored teeth with radiolucent lesions were used in this study. The teeth were photographed before extraction. The extracted teeth were transformed to 10% buffered formalin for fixation. The specimens were examined and photographed using stereoscope, then the specimens were processed for light and scanning electron microscopic examination. In addition, aspiration biopsy was done in some cases when localized swelling was noticed.

The histopathologic examination of the periapical granuloma showed extensive chronic inflammation and some focal acute inflammatory cell response. Surrounding the central nidus of the inflammatory response are loose to dense reactive collagenous stroma and some granulation tissue.

The aspiration biopsy of the periapical abscess showed abundant neutrophils, few squamoid cells and occasional histiocytes. Scanning electron microscopic examination of the periapical granuloma showed root end lesion with its folded nature and supporting collagen fibers. Also some specimens showed a central cavity with no epithelial lining.
Saudi Dental Journal 1992;4(SI)-Abstr.72:p73.

Dentin adhesives and composite resins have been widely used in recent years. Dentin adhesives adhere to the tooth and the composite resin. Bonding composites to dentin would provide the advantages of eliminating or reducing marginal leakage, reducing recurrent decay and maintaining tooth structure with more conservative cavity preparations. The purposes of this poster presentation are:

The shear bond strength (kg/cm², X + SEM) to primary molars was 85.6 + 13.7, to permanent molars was 124.0 + 9.3. The bond strength of Gluma/Lumifor to primary molars was statistically and significantly lower than to permanent teeth. Dentin surface of the fracture test specimens following application of Gluma cleanser showed remnants of the restorative resin and/or Gluma dentin bond remained on the surface. In contrast, dentin surface of the fractured test specimens following application of 37% phosphoric acid showed resin remnants partially occluding the dentinal tubules. These resin tags were broken off close to the surface.
Saudi Dental Journal 1992;4(SI)-Abstr.73:p74.

Recent advances in composite resin and dentin adhesive technology have resulted in a greater acceptance and use of these restorative materials. The purposes of this study were to measure and compare tensile bond strength and etching pattern of buccal and lingual dentin of primary molars to Gluma/LumiforR system following application of Gluma cleanser and 37% phosphoric acid. Twelve specimens in each group were used to measure tensile bond strength using an Instron testing facility at cross head speed of 1 mm/min. The tensile bond strength ofGluma/Lumifor to buccal dentin using Gluma cleanser averaged 5.53±3.27(X ± SD MPa) while for lingual dentin averaged 3.95 ± 1.61 MPa. The tensile bond strength of Gluma/Lumifor to buccal dentin using 37% phosphoric acid averaged 0.81 ± 0.90 MPa. There was no statistically significant difference in tensile bond strength of Gluma to buccal and lingual dentin using Gluma cleanser. SEM examination of the etching pattern of buccal and lingual dentin following application of the Gluma cleanser showed partial plugging of the dentinal tubules. However, these plugs were more common and evident on the buccal than the lingual dentin. In contrast, the etching pattern of the buccal dentin following application of 37% phosphoric acid showed removal of all traces of peritubular dentin creating definite tubular orifices. In conclusion, Gluma/Lumifor provides moderately good bonding to buccal and lingual dentin when using Gluma cleanser. The bond strength of Gluma/Lumifor to buccal dentin using 37% phosphoric acid were statistically and significantly lower than to buccal and lingual dentin using Gluma cleanser.
Saudi Dental Journal 1992;4(SI)-Abstr.74:p75.

The purpose of this study was to assess the pattern of lichen planus cases reported at the College of Dentistry, King Saud University.

One-hundred-sixteen dental records representing the reported cases at the College, since the establishment of the dental clinics until now, were reviewed and studied in relation to age and sex distribution, site distribution, systemic conditions, local findings, and occupation. The results indicated that the most common form of lichen planus among the studied cases were the reticular types, 88% (90% in males and 86% in females). The most commonly affected sites were found to be the right and left buccal mucosa (78% each), followed by the tongue (43%), hard palate (41%), the gingiva (31%), and soft palate (1 %). Among the local findings, 77% of the patients were found to have posterior amalgam restorations (60% male and 93% female). Twenty patients (17%) were found to be diabetics and eleven patients (10%) gave history of stress.

The findings of this study will shed some light on the expected forms of lichen planus that could be seen in patients visiting the dental clinics in Riyadh area and some of the associated local and systemic factors.
Saudi Dental Journal 1992;4(SI)-Abstr.75:p76.