title: Clinical and histological evaluation of white ProRoot MTA in direct pulp capping. Comparison of CaOH with MTA for Direct Pulp Capping Tunnel defects in dentin bridges: their formation following direct pulp capping. Histological evaluation of mineral trioxide aggregate and calcium hydroxide in direct pulp capping of human immature permanent teeth.
abstract: PURPOSE To evaluate the clinical , radiographical and histological findings in human third molars in which mechanical pulp exposures were capped with white ProRoot mineral trioxide aggregate ( WMTA ) . METHODS Forty-eight human third molars , caries-free or with incipient caries , scheduled to be extracted , were used and r and omly divided into two groups : Group A : ( n= 24 ) received WMTA and control Group B : ( n= 24 ) received chemical set calcium hydroxide ( Dycal ) . The teeth were isolated with rubber dam and Class I cavities prepared . Pulp exposure was performed using a sterile diamond bur and confirmed by frank bleeding . A sterile cotton pellet dipped in saline solution was placed over the exposure for 60 seconds . The preparation was then lightly rinsed with water and gently air-dried . WMTA or CH was placed over the exposure site followed by a small amount of a light-cured compomer . After etching with 35 % phosphoric acid gel for 15 seconds , rinsing and blot drying , Prime and Bond NT adhesive was applied and light-cured . The cavity was then restored with a resin composite and light-cured . Evaluations were performed by phone after 7 days and clinical ly at 30 + /- 5 and 136 + /- 24 days , using st and ardized tests and radiographs . The teeth were extracted after 136 + /- 24 days ; the roots were cut + /- 4 - 5 mm from the apex to allow for rapid fixation in 10 % neutral buffered formalin . They were then processed for routine histological evaluation , embedded in paraffin , sectioned and stained with hematoxylin and eosin and Brown and Brenn for recognition of bacteria . Statistical analyses were performed using a Mann-Whitney U-test , a Chi-square test , a Fisher 's exact test and an ANOVA . RESULTS No significant differences in post-operative sensitivity were reported after 7 days between the two material s ( P > 0.05 ) . Clinical examination demonstrated no significant differences at 30 + /- 5 days ( P > 0.05 ) and at 136 + /- 24 days ( P > 0.05 ) . Histological findings : 45 of 48 teeth were suitable for microscopic evaluation ( 22 with WMTA and 23 with CH ) . Twenty from the WMTA and 18 from the CH group had developed a bridge . No statistically significant differences were found for superficial and deep inflammatory cell response ( P > 0.05 ) , presence of a dentin bridge ( P > 0.01 ) , and pulp vitality ( P > 0.01 ) , between WMTA and calcium hydroxide . A statistically significant difference was found for the diameter of exposure ( P < or = 0.05 ) between WMTA ( x= 0.35 + /- 0.19 mm ) and CH ( x= 0.25 + /- 0.09 mm ) . Only a minimal association between clinical and histological findings could be established for either material This practice -based , r and omized clinical trial evaluated and compared the success of direct pulp capping in permanent teeth with MTA ( mineral trioxide aggregate ) or CaOH ( calcium hydroxide ) .  Thirty-five practice s in Northwest PRECEDENT were r and omized to perform direct pulp caps with either CaOH ( 16 practice s ) or MTA ( 19 practice s ) . Three hundred seventy-six individuals received a direct pulp cap with CaOH ( n = 181 ) or MTA ( n = 195 ) . They were followed for up to 2 yrs at regular recall appointments , or as dictated by tooth symptoms . The primary outcomes were the need for extraction or root canal therapy . Teeth were also evaluated for pulp vitality , and radiographs were taken at the dentist ’s discretion . The probability of failure at 24 mos was 31.5 % for CaOH vs. 19.7 % for MTA ( permutation log-rank test , p = .046 ) . This large r and omized clinical trial provided confirmatory evidence for a superior performance with MTA as a direct pulp-capping agent as compared with CaOH when evaluated in a practice -based research network for up to 2 yrs ( Clinical Trials.gov NCT00812887 ) This study was conducted to observe the formation and nature of tunnel defects in dentin bridges  , assess the nature of the associated soft tissue elements , and note the relationship of pulp inflammation and necrosis associated with these defects . A total of 235 teeth with class 5 cavity preparation exposures were r and omly distributed throughout the dentitions of 14 adult rhesus monkeys . Each pulp was exposed and left open to the oral microflora at one of four time intervals , flushed with saline , debrided , capped with one of two hard-set calcium hydroxide medicaments [ Ca(OH)2 ( Dycal or Life ) ] and restored with a dispersed-phase amalgam alloy . Observation times were 14 days , 5 weeks , and 1 and 2 years . A total of 192 dentin bridges formed against the Ca(OH)2 medicaments Life or Dycal in 235 pulp-capped teeth . Considering all four capping periods , 89 % of all dentin bridges contained tunnel defects ( 172 of 192 ) . Forty-one percent ( 78 ) of the 192 dentin bridges were associated with recurring pulp inflammation or necrosis and were always associated with the presence of inflammatory cells and stained bacterial profiles . This study demonstrates that a statistically significant number of dentin bridges contain multiple tunnel defects , most of which appear to remain patent . These patent tunnels fail to provide a hermetic seal to the underlying pulp against recurring infection due to microleakage . Most Ca(OH)2 medicaments have been reported to disintegrate and wash out after 6 months , leaving a void underneath the restoration and thereby a pathway for bacterial infection . This study reemphasizes the need to employ biologically relevant measures that will provide a long-term clinical seal against microleakage following direct pulp capping with Ca(OH)2 medicaments alone PURPOSE To evaluate histological findings in human immature permanent premolars scheduled for extraction for orthodontic reasons , in which mechanical pulp exposures were capped with white ProRoot Mineral Trioxide Aggregate ( WMTA ) or calcium hydroxide ( CH ) . METHODS Forty-eight human immature premolars in 23 patients ( age 10 - 18 years ) were r and omly treated with  WMTA or CH . After rubber dam isolation Cl I cavities were prepared and the pulps exposed . After hemostasis the pulps were capped with either material . The preparations were restored using an acid etch , bonding agent , flowable composite and composite resin technique . The teeth were extracted after 47 to 609 days and processed for routine histological examination , stained with hematoxylin and eosin and Brown and Brenn for recognition of bacteria . Statistical analyses of inflammation , bridge formation and bacterial leakage were performed using a Chi-square test and ANOVA . RESULTS Forty-four of 48 teeth were suitable for microscopic evaluation , 30 with WMTA , 14 with CH . Of the WMTA group , 29 teeth were vital , 28 had formed a bridge , and one specimen had failed . Twelve of 14 teeth with CH were vital , while three teeth failed to form a bridge . No statistically significant differences between WMTA and CH were found , except for superficial and deep inflammatory cell response ( P < or = 0.05 ) . Pulp capping of intentionally exposed human immature premolars performed slightly better when using MTA
target: In conclusion , MTA has a higher clinical success rate for direct pulp capping comparing to calcium hydroxide , and might be a suitable replacement for calcium hydroxide
background: Direct pulp capping is one of the most common dental practice s in endodontic therapy .
  This systematic review and meta- analysis aim to determine whether the effect of mineral trioxide aggregate ( MTA ) and calcium hydroxide for direct pulp capping is different , as measured by the clinical and radiographic analysis .