Microsoft Word - 56 2016.docx   Vol  4,  No  1  (2016)   ISSN  2167-­‐8677  (online)   DOI  10.5195/d3000.2016.56           http://dentistry3000.pitt.edu     New  articles  in  this  journal  are  licensed  under  a  Creative  Commons  Attribution  4.0  United  States  License.     This  journal  is  published  by  the  University  Library  System,  University  of  Pittsburgh  as  part  of  its  D-­‐Scribe  Digital  Publishing  Program  and  is  cosponored   by  the  University  of  Pittsburgh  Press.     The  effect  of  polymer  burs  on  microbiological  reduction  of  carious   dentin  in  deciduous  teeth:  a  systematic  review   Daniela  Silva  Barroso  de  Oliveira1,  Driely  Barreiros1,  Léa  Assed  Bezerra  da  Silva1,  Raquel  Assed  Bezerra  da  Silva1,  Paulo  Nelson-­‐Filho1,  Erika  Cal-­‐ vano  Küchler1     1Department  of  Pediatric  Den+stry,  School  of  Den+stry  of  Ribeirão  Preto/University  of  São  Paulo,  Ribeirão  Preto,  SP,  Brazil Abstract   Background.  Polymer  bur  is  a  new  technology  that  proposes  to  conserve  the  den7n  that  is   capable  of  remineraliza/on.  Aim:  To  conduct  a  quan+ta+ve  systema+c  review  to  evaluate   the  effect  of  polymer  burs  on  the  reduc3on  of  Streptococcus  mutans  and  Lactobacillus  a"er   den$n  carious  excava$on   in  deciduous   teeth.  Methods  and  Material:  Two  reviewers  per-­‐ formed   the   database   to   iden/fy   the   relevant   clinical   papers.   Only   papers   in   English   that   compared  polymer  burs  with  other  caries  removal  techniques  with  the  microbiological  as-­‐ pects  as  an  outcome  were  included.  Papers  that  evaluated  only  permanent  teeth  were  ex-­‐ cluded.  Risk  of   bias  was   also   assessed.   Individual   study  effect   sizes  were   calculated  using   Cohen’s  d  formula  for  the  comparisons  of  microorganism  reduc5on  before  and  a&er  carious   excava&on.  Results:  The  search  resulted  in  12  non-­‐duplicated  papers.  A/er  the  revision,  on-­‐ ly  2  were  selected.  The  quan3ta3ve  evalua3on  demonstrated  that  polymer  bur  reduces  mi-­‐ croorganism  levels  in  carious  den0n.  The  larger  effect  size  observed  was  for  Streptococcus   mutans  in  the  polymer  bur  technique  (r=0.84;  d=3.12),  followed  by  Lactobacillus  in  the  car-­‐ bide  bur   technique   (r=0.83;  d=3.03).  Conclusion:  Polymer  burs  promoted  a   significant   re-­‐ duc$on  of  microorganism  levels,  mainly  Streptococcus  mutans  in  carious  den,n.     Cita%on:  Oliveira,  et  al.  (2016).  The  effect  of  pol-­‐ ymer  burs  on  microbiological  reduc1on  of  cari-­‐ ous  den(n  in  deciduous  teeth:  a  systema(c  re-­‐ view.  Den$stry  3000.  1:a001   doi:10.5195/d3000.2016.56   Received:  July  12,  2016   Accepted:    July  23  ,  2016   Published:    October  3,  2016   Copyright:  ©2016  Oliveira,  et  al.  This  is  an  open   access   ar!cle   licensed   under   a   Crea!ve   Com-­‐ mons   A"ribu"on   Work   4.0   United   States   Li-­‐ cense.   Email:  erikacalvano@gmail.com   Introduction   Dentinal  caries  is  structur-­‐ ally  divided  into  infected  and  af-­‐ fected  dentin.  The  superficial  layer   is  the  infected  dentin.  It  is  irre-­‐ versible  denatured  and  extensively   demineralized.  The  deeper  layer  is   the  affected  dentin  and  is  bacte-­‐ ria-­‐free.  It  is  potentially  and  physi-­‐ ologically  remineralizable,  with   odontoblastic  process,  sound  col-­‐ lagen  fibers  and  apatite  crystal   bound  to  the  fibers  [1-­‐6].  The  min-­‐ imally  invasive  dentistry  concept   implies  that  the  infected  and  irre-­‐ versibly  denatured  dentin  should   be  removed  selectively  to  pre-­‐ serve  as  much  as  possible  sound   or  potentially  remineralizable  den-­‐ tin  [3,7].  However,  a  balance  be-­‐ tween  tissue  preservation  and  in-­‐ fected  dentin  removal  should  be   achieve  in  order  to  prevent  caries   progression  [4,8-­‐9].   Conventional  methods  for   carious  dentin  removal  include   manual  excavation  with  hand  ex-­‐ cavators  and  burs  associated  with   low  or  high-­‐handpieces  [10].  Both   are  dependent  of  the  operator's   optical  and  tactile  sensitivity  and   may  lead  to  an  unnecessary  re-­‐ moval  of  dental  tissues  [5,8-­‐12].   Moreover,  infected  and  affected   dentin  have  some  differences  such   as  in  the  hardness,  toughness  and   resilience,  which  determine  the   relative  efficiency  of  caries  excava-­‐ tion  techniques  [2].   New  techniques  have  been   proposed  to  conserve  dental  tis-­‐ sue  that  is  able  to  remineralize  [2-­‐ 3,6,10-­‐11].  Polymer  burs  were  de-­‐ veloped  (Smartbur-­‐SS  White  Com-­‐ pany  -­‐  Lakewood,  NJ,  USA)  to  be   used  with  conventional  low-­‐speed   handpieces  that  proposes  a  self-­‐ limiting  technology,  to  provide  se-­‐ lective  caries  removal.  These  burs   are  single-­‐use  instruments,  made   with  a  polymer  that  presents  value   of  hardness  Knoop  (KHN)  equal  to   50.  This  hardness  value  is  lower   than  healthy  dentin  (70-­‐90),  but   The  effect  of  polymer  burs  on  microbiological  reduc7on  of  carious  den7n  in  deciduous  teeth:  a  systema7c  review   Vol  4,  No  1  (2016)        DOI  10.5195/d3000.2016.56    http://dentistry3000.pitt.edu   2   higher  than  that  the  carious  or  in-­‐ fected  dentin  (0-­‐30)  [3-­‐5,10].  Pol-­‐ ymer  burs  have  the  potential  to   selectively  remove  the  carious   dentin,  since  they  lose  their  cut-­‐ ting  capacity,  becoming  blunt,   when  touching  the  affected  and   healthy  dentin  [3-­‐5,8-­‐9,12].   Although  several  in  vitro   [4-­‐5,9-­‐11,13]  and  in  vivo  [6,8,12]   papers  evaluated  the  effectiveness   of  polymer  burs  in  selectively  re-­‐ move  the  infected  carious  dentin,   their  effect  on  the  microbiological   reduction  is  still  imprecise.  Thus,   the  aim  of  this  study  was  to  evalu-­‐ ate  the  effect  of  the  polymer  burs   on  the  reduction  of  Streptococcus   mutans  and  Lactobacillus  after   dentin  carious  excavation  in  de-­‐ ciduous  teeth,  through  a  quantita-­‐ tive  systematic  review.   Materials  and  methods   Protocol  and  registration   To  conduct  this  review,  the   PRISMA  STATEMENT  checklist  was   used  [14].  The  study  was  regis-­‐ tered  in  the  international  prospec-­‐ tive  register  of  systematic  reviews   ‘‘PROSPERO’’   (www.crd.york.ac.uk/PROSPERO)   (registration  number   CRD42015016678).   Search  Strategy     The  search  strategy  was   based  on  the  followingMedical   Subject  Heading  terms  (MeSH)  or   Text  Word  [tw]  in  different  combi-­‐ nation  strategy:  “polymers”   [MeSH  terms]  OR  “polymer”  [tw]   AND  “burs”  [tw]  OR  “bur”  [tw]  OR   “drill”  [tw]  AND  “dental  caries”   [MeSH  terms]  OR  “caries  removal”   [tw]  OR  “caries  excavation”  [tw].   Using  the  following  data-­‐ bases,  the  search  of  the  literature   was  performed:  MEDLINE  (1966–   February  2016),  Web  of  Science   (1900–  February  2016),  Scopus   (1960–  February  2016)  and  The   Cochrane  Library  (1993-­‐  February   2016).   Attempts  to  obtain  missing   information,  additional  manual   search  were  performed  to  find  fur-­‐ ther  papers  that  were  not  in  the   electronic  databases.  Reference   lists  from  identified  papers  were   scanned  to  identify  other  poten-­‐ tially  relevant  papers.     Inclusion  and  Exclusion  Criteria   The  inclusion  criteria  were  as  fol-­‐ lows:   1.  Papers  in  English.   2.  Clinical  papers.     3.  Papers  that  evaluate  the  effect   of  the  polymer  burs  on  the  reduc-­‐ tion  of  microorganisms.   4.  The  outcome  was  to  evaluate   microbiological  aspects.     Table&1.!!Summary!of!data!reported!in!selected!articles!addressing!polymer!burs!and!caries!removal! Study& Number&of& participants& and&teeth& Age& range& Study&& design& Microbiological& evaluation& Microorganisms&& analyzed& Authors&& conclusions& ! ! 12.!Isik!et! al.,!2010! 24!patients! ! 48!teeth! ! 5A9! Same!child! received!both! treatments! assigned!into!2! groups:! 1)!Round!carbide! burs!! 2)!Polymer!burs! Growth!in!culture! media!(CFU)!and! biochemical! fermentation!test! 1)#Streptococcus#mutans# 2)#Lactobacillus# 3)!Aerobic!microorganisms! 4)!Anaerobic!microorganisms!! !!!No!statistically!significant! differences!in!microorganisms! reduction!between!round! carbide!burs!and!polymer!burs! in!all!microbiological!test!used.! ! ! 8.! Zakirulla! et!al.,! 2011! 36!patients! ! 45!teeth! 6A14! Division!into!3! groups:! 1)!Round!carbide! burs! 2)!Polymer!burs! 3)!Spoon! excavator! Growth!in!culture! media!(CFU)! 1)#Streptococcus#mutans# 2)#Lactobacillus# ! Polymer!burs!showed! statistically!significant!more! reduction!for!Lactobacillus,!but! not!for!S#mutans#when! compared!with!spoon! excavator.##Round!carbide!burs! showed!statistically!significant! more!reduction!for!S.#mutants# and!Lactobacillus#when! compared!to!polymer!burs.! Note:&CFU=Colony!Forming!Unit& ! The  effect  of  polymer  burs  on  microbiological  reduc7on  of  carious  den7n  in  deciduous  teeth:  a  systema7c  review   Vol  4,  No  1  (2016)        DOI  10.5195/d3000.2016.56    http://dentistry3000.pitt.edu   3   The  exclusion  criteria  included  the   following:     1.  Papers  in  vitro,  ex-­‐vivo,  case  re-­‐ ports,  case  series,  studies  with  an-­‐ imal  models  and  reviews.   2.  Papers  without  comparison  of   the  polymer  bur  with  other  tech-­‐ nique.   3.  Papers  that  evaluated  only   permanent  teeth.   Unpublished  results,  thesis,   book  chapters,  abstracts  and  re-­‐ views  were  not  included.   Selection  Criteria   All  potentially  relevant  pa-­‐ pers  were  identified  by  the  title   and  the  abstract.  After  that,  the   full  text  analyses  were  performed   to  include  the  paper  in  the  sys-­‐ tematic  review.     Two  examiners  (DSBO  and   DB)  evaluated  titles,  abstracts  and   full  text.  If  there  was  a  diverging   opinion,  disagreement  among  ex-­‐ aminers  was  reexamined  in  con-­‐ sensus  meetings.   Data  extraction   One  author  (DSBO)  ex-­‐ tracted  the  relevant  data  from  the   included  papers.  From  each  in-­‐ cluded  study,  the  description  of   the  sample,  the  study  design,  mi-­‐ crobiological  evaluation  and  re-­‐ sults  were  summarized  in  the  ta-­‐ ble  1.  Other  author  (ECK)  checked   the  extracted  data.  Disagreements   between  the  two  researchers   were  resolved  by  discussion  and   consensus.   Assessment  of  risk  of  bias   The  quality  assessment  of   the  remaining  papers  was  per-­‐ formed  to  evaluate  methodologi-­‐ cal  aspects  related  to  influence   bias,  to  gain  insight  into  the  results   of  the  techniques  comparisons   and  to  guide  the  interpretation  of   qualitative  and  quantitative  find-­‐ ings.   Five  criteria  were  used  to   analyze  all  included  papers:  1)   sample  size  calculation;  2)  random   allocation  of  the  participants;  3)   participants’  eligibility,  4)  inclusion   and  exclusion  criteria;  5)  standard-­‐ ization  of  the  investigator.  Two  of   the  reviewers  (PNF  and  ECK)  as-­‐ sessed  the  included  papers  for  risk   of  bias  and  were  blinded  to  each   other's  assessments.  Disagree-­‐ ments  were  resolved  through  dis-­‐ cussions  with  a  third  review   (RABS).  Domains  from  the   Cochrane  Collaboration  risk  of  bias   tool  were  assessed  for  each  study.   Data  were  entered  into  Review   Manager  5.3  (RevMan  5.3)  for  the   graphical  representation.   Calculation  of  the  effect  size   Comparisons  of  microor-­‐ ganism  reduction  before  and  after   dentin  carious  excavation  were   performed  for  each  study  and   each  comparison  group.  In  order   to  pool  data,  means  and  standard   deviations  were  converted  into   The  effect  of  polymer  burs  on  microbiological  reduc7on  of  carious  den7n  in  deciduous  teeth:  a  systema7c  review   Vol  4,  No  1  (2016)        DOI  10.5195/d3000.2016.56    http://dentistry3000.pitt.edu   4   effect  size.  When  the  results  were   presented  as  median,  the  mean   value  and  the  standard  was  calcu-­‐ lated  using  the  formula  proposed   by  Hozo  et  al.  [15].  Individual   study  effect  sizes  for  the  2  includ-­‐ ed  papers,  that  presented  the  data   as  a  continuous  variable,  were  cal-­‐ culated  using  Cohen’s  d  formula   [16].  Positive  values  represented  a   reduction  of  microorganism  level.   The  effect-­‐size  was  classified  as   suggested  by  Cohen  [16],  in  low   effect  (d≤0.2),  medium  effect   (0.21≤d≥0.79)  and  high  effect   (d≥0.8).   Results   A  total  of  132  titles  and  ab-­‐ stracts  were  screened  from  the   selected  databases.  There  were   110  in  PubMed,  10  in  Web  of  Sci-­‐ ence,  8  in  Scopus  and  4  in   Cochrane.  The  duplicates  were   considered  only  once,  totaling  132   papers.   Initially,  the  titles  and  ab-­‐ stracts  not  connected  with  the   topic  were  excluded  (116  papers).   Afterwards,  the  papers  were  se-­‐ lected  according  to  the  inclusion   and  exclusion  criteria,  totaling  4   papers  selected  for  full  text  analy-­‐ sis.  After  reading,  2  papers  were   excluded  because  they  were  in   vitro  papers.  Thus,  2  full  texts   were  included  and  analyzed  ac-­‐ cording  to  the  selection  criteria   (figure  1).   The  summary  of  the  char-­‐ acteristics  of  the  two  included  pa-­‐ pers  is  described  in  the  table  1.   The  papers  were  also  carefully   read  and  ranked  based  on  the  risk   of  bias  as  shown  in  figure  2.     The  quantitative  analysis,   that  shows  the  effect  size  of  mi-­‐ croorganisms  reduction,  are  pre-­‐ sented  in  the  table  2.  All  tech-­‐ niques  demonstrated  a  moderate   and  large  reduction  of  Streptococ-­‐ cus  mutans  and  Lactobacillus  lev-­‐ els.  The  larger  effect  size  observed   was  for  Streptococcus  mutans  in   the  polymer  bur  technique   (r=0.84;  d=3.12),  followed  by  Lac-­‐ tobacillus  in  the  carbide  bur  tech-­‐ nique  (r=0.83;  d=3.03).     Discussion   The  removal  of  infected   carious  dentin  and  the  careful   maintenance  of  the  dentin  that  is   capable  of  remineralization  has   been  a  focus  of  the  conservative   dentistry  approaches  [3].  The  ac-­‐ tual  criteria  for  caries  removal   arise  from  the  concept  that     Table&2.!Calculation!of!effect!size!for!the!included!studies! Study& Caries&excavation&technique& Microorganism& Effect&size&score&of&the&reduction& Type&of&the&effect& R& d& 12.!Isik!et!al.,!2010! Polymer!bur! Streptococcus*mutans* 0.646! 1.695! Moderate!Reduction! Lactobacillus* 0.458! 1.033! Moderate!Reduction! ! ! Carbide!bur! Streptococcus*mutans* 0.671! 1.811! Moderate!Reduction! Lactobacillus* 0.573! 1.398! Moderate!Reduction! ! 8.!Zakirulla!et!al.,!2011! Polymer!bur!! Streptococcus*mutans! 0.842& 3.121! High!Reduction! Lactobacillus! 0.703! 1.979! Moderate!Reduction! Carbide!bur! Streptococcus*mutans! 0.624! 1.600! Moderate!Reduction! Lactobacillus! 0.835& 3.035! High!Reduction! Spoon!excavator! Streptococcus*mutans! 0.712! 2.032! Moderate!Reduction! Lactobacillus! 0.578! 1.418! Moderate!Reduction! Note:&&Bold&form&indicates&high&effect&size.& R:&effect!size!correlation! d:&Cohen’s!d& ! The  effect  of  polymer  burs  on  microbiological  reduc7on  of  carious  den7n  in  deciduous  teeth:  a  systema7c  review   Vol  4,  No  1  (2016)        DOI  10.5195/d3000.2016.56    http://dentistry3000.pitt.edu   5     “sound”  tissue  or  poten-­‐ tially  remineralizable  tissue  should   not  be  unnecessarily  removed   [5,17].  Nevertheless,  the  exact   endpoint  of  caries  removal  cannot   be  easily  clinically  defined.  This   may  be  explained  by  the  fact  that   dentists  have  been  trained  in  rely-­‐ ing  on  the  hardness  of  dentine  as   felt  with  a  dental  probe.  Other   more  subjective  characteristics,   such  as  the  dentin  color  and  mois-­‐ ture  are  often  neglected  [17].  Our   quantitative  systematic  review   aimed  to  evaluate  a  new  tech-­‐ nique  that  proposes  to  preserve   the  potentially  remineralizable   tissue  without  the  dentist´s  atten-­‐ tion  to  the  subjective  characteris-­‐ tics.   An  important  criteria  to   differentiate  infected  dentin  of   affected  dentin  is  the  number  of   viable  microorganisms  existent  in   the  remaining   dentin  [2-­‐4,6].   Therefore  we   chose  this  pa-­‐ rameter  as  an   outcome  to   evaluate  the   effectiveness  of   the  polymer   burs  to  reduce   cariogenic  mi-­‐ croorganisms.  In   the  present   study,  the  effect   size  calculation   demonstrated   that  burs,  poly-­‐ mer  burs  and   spoon  excavator   were  able  to   promote  a   moderate  and  a   large  microbiological  reduction.     Mutans  streptococci  are   the  main  etiologic  agent  of  dental   caries  in  humans  [18-­‐19],  which   explains  the  importance  of  its  re-­‐ duction  after  procedures  of  mini-­‐ mal  invasive  excavation.  Indeed,   we  observed  that  polymer  bur   promoted  the  largest  reduction  in   Streptococcus  mutans  levels.   Minimal-­‐invasive  dental   preparation,  such  as  polymer  burs,   simplifies  and  standardizes  caries-­‐ removal  procedures  [17].  In  fact,   our  results  demonstrated  that   polymer  burs  may  offer  a  viable   and  efficient  means  to  achieve   minimal-­‐invasive  dental  prepara-­‐ tion.  Maintain  the  healthy  dental   structures  as  previously  described   [3-­‐5].     Our  results  showed  that   the  polymer  burs  were  more  ef-­‐ fective  in  Streptococcus  mutans   removal,  while  conventional  burs   provided  a  further  reduction  of   Lactobacillus.  As  conventional   burs  are  more  invasive  than  poly-­‐ mer  burs  and  usually  extends  into   the  affected  dentine  [3,5,13],  this   might  lead  to  a  larger  reduction  of   Lactobacilli  which  are  strictly  an-­‐ aerobic,  highly  sensitive  to  pH  rais-­‐ ing  and  located  in  the  deeper  por-­‐ tions  of  the  carious  dentin  [20-­‐22].   The  included  papers  have   some  limitations  that  directly  re-­‐ flect  our  review  results.  None  of   them  attempted  to  perform  a   sample  size  calculation,  and  only   one  paper  performed  a  random   allocation  of  used  teeth  and  the   standardization  of  the  investigator   for  the  polymer  burs  use.  In  addi-­‐ tion,  it  is  important  to  emphasize   that  a  long-­‐term  follow  up  should   be  perform  in  order  to  evaluate  a   real  clinical  efficiency  regarding   the  caries  lesion  recurrence.     Although  in  all  techniques   evaluated  in  the  included  papers,   there  was  reminiscent  number  of   viable  microorganisms  in  the   deeper  layers  of  dentin,  we  can   assume  that  the  subsequent  seal-­‐ ing  performed  by  the  restoration   could  solve  this  issue,  as  previous-­‐ ly  demonstrated  [23].  Therefore,   the  maintenance  of  the  cavity   sealing  through  a  dentinoenamel   junction  free  from  caries  and  ad-­‐ hesive  restorations  would  inter-­‐ rupt  the  communication  of  bacte-­‐ ria  present  in  dentin  with  the  sur-­‐ face  biofilm,  with  a  consequent   reduction  in  nutrients  and  bacteri-­‐ al  viability  [24].       The  effect  of  polymer  burs  on  microbiological  reduc7on  of  carious  den7n  in  deciduous  teeth:  a  systema7c  review   Vol  4,  No  1  (2016)        DOI  10.5195/d3000.2016.56    http://dentistry3000.pitt.edu   6   How  does  a  polymer  bur  actually   provide  clinical  benefits?     Although  this  study  aimed   to  answer  the  question  about  the   efficacy  of  the  polymer  burs  for   microorganism’s  reduction  during   carious  removal,  it  raises  ques-­‐ tions  that  should  be  considered  by   clinical  researchers.  Microorgan-­‐ isms  reduction  comparison  does   not  necessary  allows  the  re-­‐ searchers  and  clinicians  to  infer   which  is  the  most  effective  meth-­‐ od  for  minimal  invasive  approach.   Furthermore,  the  use  of  polymer   burs  does  not  eliminate  the  need   of  conventional  burs,  which  may   be  necessary  for  the  enamel  re-­‐ moval  to  access  the  carious  den-­‐ tin.     The  polymer  burs  proposes   for  the  clinicians  a  less  invasive   option  for  deep  decay  removal,   while  leaving  healthy  dentin  intact   (Smartbur-­‐SS  White  Company-­‐ Lakewood,  NJ,  USA).  This  study   demonstrated  that  conventional   methods  and  the  polymer  burs   reduce  levels  of  Streptococcus  mu-­‐ tans  and  Lactobacillus.  However,   since  the  polymer  burs  are  selec-­‐ tive  for  carious  dentin  remove,  it   should  be  an  option  for  clinicians   to  preserve  sound  dentin.  In  addi-­‐ tion,  it  has  been  proposed  that   this  technique  may  eliminate  the   use  of  local  anesthesia3.  However,   the  researchers  should  largely  in-­‐ vestigate  the  clinical  benefit  of  this   new  instrument.   Suggestion  for  Future  Papers   Based  on  this  systematic   review,  some  questions  should  be   answered  in  future  papers.  First,   although  it  is  accepted  that  the   dental  restoration  is  effective  to   deal  with  the  microorganisms  left   in  the  remaining  dentin,  a  long   term  follow  up  should  be  per-­‐ formed.  Also,  since  there  were  no   remarkable  differences  in  micro-­‐ organisms  reduction  among  the   minimal  invasive  techniques,  fu-­‐ ture  clinical  papers  should  attempt   to  evaluate  the  effectiveness  of   the  polymer  bur  in  a  multilevel   design  study,  in  which  preparation   time,  peculiarities  of  this  new   technique,  operator  training,  as-­‐ sessment  of  important  clinical  cri-­‐ teria  such  as  pain,  sensitivity  to   pressure,  vibration  and  tempera-­‐ ture  changes  and  cost  (single  use   instrument)  of  the  polymer  bur   should  be  included.   Finally,  definitive  clinical   conclusions  about  the  effective-­‐ ness  of  polymer  burs  were  not  de-­‐ scribed  in  this  paper  as  only  one   outcome,  the  microbiological,  was   evaluated.  Other  important  pa-­‐ rameters  such  as  evaluation  of   hardness,  color  and  humidity  are   important  in  assessing  the  carious   dentin  removal.  Furthermore,  pa-­‐ pers  evaluating  the  long-­‐term  re-­‐ maining  dentin  are  important  to   determine  if  the  number  of  bacte-­‐ ria  remaining  after  carious  dentin   removal  with  polymer  burs  will   not  be  viable  for  the  recurrence  of   caries.    In  conclusion,  polymer   burs  promote  the  reduction  of  mi-­‐ croorganism  levels,  mainly  Strep-­‐ tococcus  mutans.     References   1. 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