Effect of root canal irrigant (sodium hypochlorite & saline) delivery at different temperatures and durations on pre-load and cyclic-loading surface-strain of anatomically different premolars.

AIM: To evaluate the effect of NaOCl (5%) and saline (control) irrigant delivery at different temperatures and durations on pre-load and cyclic-loading tooth-surface-strain (TSS) on anatomically different premolars. METHODOLOGY: Single-rooted premolars (n = 36), root-canal-prepared in standard manner, were randomly allocated to six irrigation groups: (A1) NaOCl-21 °C; (A2) NaOCl-60 °C; (A3) saline-21 °C then NaOCl-21 °C; (A4) saline-60 °C then NaOCl-21 °C; (A5) saline-21 °C then NaOCl-60 °C; (A6) saline-60 °C then NaOCl-60 °C. A1-2 received nine 10-min irrigation periods (IP) with NaOCl; A3-6 received nine 10-min IP with saline, followed by 9 IP with NaOCl at different temperature combinations. Premolars (n = 56) with single, fused or double roots prepared by standard protocol, were stratified and randomly allocated to: (B1) saline-21 °C; (B2) saline-80 °C; (B3) NaOCl-21 °C; (B4) NaOCl-80 °C. TSS (µÑ”) was recorded pre-irrigation, post-irrigation and pre-load for each IP and during cyclic loading 2 min after each IP, over 30-274 min, using strain-gauges. Generalised linear mixed models were used for analysis. RESULTS: Baseline TSS in double-rooted premolars was significantly (p=0.001) lower than in single/fused-rooted-premolars; and affected by mesial-wall-thickness (p=0.005). There was significant increase in loading-TSS (µÑ”) after NaOCl-21 °C irrigation (p=0.01) but decrease after NaOCl-60 °C irrigation (p=0.001). TSS also increased significantly (p = 0.005) after Saline-80 °C irrigation. Pre-load "strain-shift" was noted only upon first saline delivery but every-time with NaOCl. Strain-shift negatively influenced loading-TSS after saline or NaOCl irrigation (A3-6) but was only significant for saline-21 °C. CONCLUSIONS: Tooth anatomy significantly affected its strain characteristics, exhibiting limits within which strain changes occurred. Intra-canal introduction of saline or NaOCl caused non-random strain shifts without loading. Irrigation with NaOCl-21 °C increased loading tooth strain, as did saline-80 °C or NaOCl-80 °C but NaOCl-60 °C decreased it. A "chain-link" model was proposed to explain the findings and tooth biomechanics.

Trichohepatoenteric Syndrome or Syndromic Diarrhea-Report of Three Members in a Family, First Report from Iran.

Introduction. Intractable diarrhea of infancy (IDI) includes several types of early onset diarrhea; one of the rare etiologies is trichohepatoenteric (THE) syndrome, also known as syndromic diarrhea (SD) which was primarily described by Stankler et al. Hereby we report a family with several affected members which to our knowledge is the first case report from Iran. Report of Cases. A three-year-old boy referred with short stature, poor weight gain, and intermittent steatotic diarrhea to our center. He was born to healthy, relative parents (cousins). He did not gain any weight after four months of age and began having intermittent steatotic diarrhea, abdominal distension, and fever. He was hospitalized several times. Two other children in the family also showed somewhat similar symptoms. Two sweat tests were negative for cystic fibrosis. Workup for Celiac disease was performed several times which was negative; however, gluten-free diet was tried several times which was not effective. Workup for Hirschsprung's disease was performed but colon was ganglionic. Evidence of liver involvement was approved by elevated liver enzymes and coarse echo of liver on sonography. Discussion. Trichoenterohepatic syndrome should be put in mind in cases of intractable diarrhea presenting in a family with several affected members. Early diagnosis would save patients from unnecessary workups.