Journal club on Minimally Invasive Single Implant Treatment (M.I.S.I.T.) based on ridge preservation and contour augmentation in patients with a high aesthetic risk profile.

Minimally Invasive Single Implant
Treatment (M.I.S.I.T.) based on ridge
preservation and contour
augmentation in patients with a high
aesthetic risk profile: one-year results
Cosyn J et al, JCP 2015; 42: 398–405.
Shilpa Shivanand
II MDS

INTRODUCTION
• Immediate implant placement is a popular treatment concept
in contemporary practice.
• Predictable results can be achieved in patients with an intact
buccal bone wall and thick gingival biotype
Cosyn et al 2012
• However, clinical reality shows that a buccal bone dehiscence
or fenestration is common following tooth extraction.
• In addition, a thin scalloped gingival biotype can be found in
about one-third of the population.
De Rouck et al 2009

• Given their risk profile, these patients are usually treated in a
more conservative way.
• This includes flap surgery for implant placement after a post-
extraction healing period of at least 6 weeks, often combined
with GBR in case of bone deficiency.
Buser et al 2008, Cosyn 2012, De Rouck 2009
• Although these procedures have been shown to be
predictable from a clinical and radiographic point of view,
multiple studies have shown poor aesthetic results, especially
after bone augmentation
Cosyn et al 2012, den Hartog et al 2013

Minimally Invasive Single Implant
Treatment (M.I.S.I.T.) ?

AIM
• The goal of this prospective study was to explore the outcome
of Minimally Invasive Single Implant Treatment (M.I.S.I.T.)
based on ridge preservation and contour augmentation in
patients with a buccal bone dehiscence and/or thin-scalloped
gingival biotype.
• Mid-facial recession at the failing tooth has been considered
another aesthetic risk factor
Martin et al 2007
• Hence, another goal was to explore the outcome of M.I.S.I.T.
in patients with mid-facial recession at the failing tooth.

MATERIALS AND METHODS
• Patients with a failing tooth were enrolled in a private practice
in Belgium between April 2011 and December 2012 to
participate in a prospective case series.
• All patients were in need of a single implant.

INCLUSION CRITERIA
• At least 18 years old.
• Good oral hygiene defined as full-mouth plaque score ≤25%
(O’Leary et al. 1972).
• Presence of a single failing tooth in the anterior maxilla (upper
right to upper left second premolar) with both neighbouring
teeth present.

INCLUSION CRITERIA …
• High aesthetic risk profile characterized by at least one of the
following:
1. mid-facial recession at the failing tooth in reference to the
contra-lateral tooth
2. buccal bone dehiscence (regardless of depth) at the time of
tooth extraction
3. thin-scalloped gingival biotype as determined by the
transparency of a periodontal probe in the buccal sulcus of
the contra-lateral tooth
De Rouck et al 2009

EXCLUSION CRITERIA
• Systemic diseases.
• Smoking.
• Periodontal disease or history of periodontal treatment.

STUDY GROUPS
• As the presence of mid-facial recession at the failing tooth
was decisive for the treatment trajectory, patients were
included in the so called “non-recession group” (NRG) or
‘recession group’ (RG).
• The study protocol was approved by the ethics committee of
the University Hospital in Brussels (ID: 143201111007).

TOOTH EXTRACTION AND RIDGE
PRESERVATION IN THE NON-RECESSION GROUP
(NRG)
• Antibiotic therapy (Amoxicillin 1 g, twice daily for 4 days) was
started 1 h pre-operatively.
• Prior to tooth extraction, patients rinsed with a 0.2%
chlorhexidine solution.
• Teeth were extracted without flap elevation.
• Following meticulous bone curettage a collagen-enriched
bovine derived xenograft (Bio-Oss) was inserted and
condensed, with the purpose of maintaining the ridge profile.

• The wound was protected with single monofilament sutures
that were removed after 2 weeks.
• Patients continued local disinfection twice a day during 2
weeks and used ibuprofen 600 mg when deemed necessary.
• A removable partial denture was used as provisional tooth
replacement in all patients.

IMPLANT PLACEMENT IN THE NON-RECESSION
GROUP (NRG)
• 4 to 6 months following ridge preservation NobelActive
implants were installed.
• Based on CBCT analysis and bone sounding, a freehanded
flapless approach was chosen using a 3.5 mm tissue punch in
a palatal position.
• In borderline cases (<6 mm buccopalatal width as measured
on CBCT) a standard flap was raised and single sutures were
applied.

CONTOUR AUGMENTATION IN THE
NONRECESSION GROUP (NRG)
• 3 months following implant placement a provisional screw
retained crown was connected onto the implant.
• To compensate for tissue loss at the buccal aspect a connective
tissue graft (CTG) harvested from the palate was used.
• The provisional crown was removed and a buccal sulcular
incision was made. A partial thickness pouch procedure with a
depth of about 12 mm was prepared.
• A CTG with appropriate size was pulled into the envelope and
sutured. Finally, the provisional crown was reinstalled.
• Sutures were removed after 1 week.

Permanent crown in the non-recession
group (NRG)
• Provisional crowns were adapted at the buccal aspect in case
of coronal migration of the mucosal margin.
• Following roughening with a diamond bur, flowable composite
was added at the buccal aspect hereby inducing soft tissue
retraction in a controlled manner.
• After 3 months of function, the emergence profile was
replicated for the permanent restoration.
• Screw-retained full-ceramic crowns were a priori chosen.

Clinical procedure in the recession group
(RC)
• Patients with mid-facial recession at the failing tooth in
reference to the contra-lateral tooth were treated in a similar
way as described above, yet they received a CTG at the time
of ridge preservation.
• A portion of that CTG was left uncovered at the coronal part.
• To limit the risk of necrosis in this area, a much larger CTG was
needed in the RG than in the NRG.

Clinical outcome
• 1  Implant success was evaluated at 3 and 12 months using
the success criteria by Buser et al 1990.

Clinical outcome…
• 2  Bone loss was recorded at the mesial and distal aspect of
each implant at 3 and 12 months with implant installation as a
reference time point.
• The distance from the implant-abutment interface to the first
bone-to-implant contact as assessed on digital peri-apical
radiographs was used as a basis for bone loss calculation.
• Mesial and distal values were averaged to receive 1 value per
implant and per time point.

Clinical outcome..
• 3  Plaque was registered at 12 months at four sites per implant
(mesial, distal, mid-facial, palatal) using a dichotomous score (0:
no visible plaque at the soft tissue margin; 1: visible plaque at the
soft tissue margin).
• 4  Probing depth was recorded at 12 months and at the same
sites to the nearest 0.5 mm using a periodontal probe.
• 5  Bleeding on probing was registered 15 s following pocket
probing. A dichotomous score (0: no bleeding; 1: bleeding was
given.
• 6  Complications from biological and technical nature were
recorded at all occasions.

Aesthetic outcome
• 1  Mesial and distal papillary recession was registered at 3
and 12 months by means of an acrylic stent provided with
direction grooves.
• Baseline registration was performed with the failing tooth still
in situ.
• A positive value corresponded to papillary recession, a
negative value to papillary gain.

Aesthetic outcome…
• 2  Mid-facial recession was recorded at 3 and 12 months in
a similar way as papillary recession.
• 3  Pink Esthetic Score (PES) (F€urhauser et al 2005) was
registered at baseline (failing tooth in situ) and at 12 months.
• 4  White Esthetic Score (WES) (Belser et al 2009) was
registered at 12 months.

STATISTICAL ANALYSIS
• Descriptive statistics included mean values and standard deviations
for age, plaque, probing depth, bleeding on probing, bone loss,
papillary recession, mid-facial recession, PES, WES, gender, reason
for tooth extraction, tooth location, presence of buccal bone
dehiscence, gingival biotype, flapless/flap surgery, maximum
implant insertion torque, implant success.
• Bone loss was evaluated over time using the paired samples t-test.

RESULTS
• The vast majority of the cases (N = 42) demonstrated a buccal
bone dehiscence following tooth extraction.
• Seventeen patients had a thin scalloped gingival biotype.
• Flapless implant placement could be performed in 40 patients
(35 in NRG and 5 in RG).
• Five patients in the NRG did not receive a CTG because of
refusal (N = 2) or because it was considered unnecessary
given the limited amount of alveolar process remodelling (N =
3).
• A second CTG was performed in one patient of the NRG and in
one patient of the RG.

Clinical outcome- results
• From the 50 consecutively treated patients, 47 could be
evaluated at 12 months.
• All 47 implants survived and 46 of those could be considered
successful.
• Significant bone loss was registered and amounted to 0.31
mm on average at 3 months and 0.48 mm on average at 12
months.
Pre-operative
radiograph
flapless implant placement
4 months following tooth
extraction and ridge
preservation
provisional crown
3 months later
permanent crown
3 months later

• At study termination mean bone loss was 0.40 mm for
implants installed via flap surgery and 0.49 for implants
installed via flapless surgery.
• Mean plaque was 17% , mean probing depth was 3.1 mm and
mean BOP as 23% at 12 months.
• The provisional crown fractured in 1 patient.
• There were no other complications up to 12 months.

Aesthetic outcome results
• Significant papillary recession was observed in the NRG
pointing to 0.2 mm on average at 12 months.
• Mid-facial recession was minimal in the NRG.
• Papillary recession did not reach statistical significance in the
RG.
• Mid-facial soft tissue gain amounted to 0.9 mm on average in
the RG at 12 months.

• Mean PES on the total sample was 11.4 at baseline and 10.9
at 12 months (p = 0.110).
• Soft tissue colour improved best, whereas soft tissue texture
deteriorated most over time.
• Mean WES was 8.2

DISCUSSION
• Risk assessment is of key importance in therapeutic decision-making
(Martin et al 2007, Cosyn et al 2012)
• Recent studies have shown poor aesthetic outcome of immediate
implant treatment in patients with a buccal bone dehiscence and a
thin-scalloped gingival biotype.
(Kan et al 2007, 2011, Cosyn et al 2012)
• Even traditional protocols based on flap surgery, GBR and bone
augmentation may fall short in these patients, atleast when optimal
aesthetics is considered a clear treatment objective
(Cosyn,De Rouck 2009, Cosyn et al 2012)

• This study showed a favourable clinical outcome of M.I.S.I.T. under
challenging conditions.
• The concept is based on ridge preservation.
• A traditional outcome measure of implant therapy is marginal
bone loss, which amounted to 0.48 mm on average after 1 year of
function.
Kielbassa et al 2009, Arnhart et al 2012, Cosyn et al 2013
• The present study showed a mean bone loss of 0.40 mm for
implants installed via flap surgery and 0.49 for implants installed
via flapless surgery.

CONCLUSION
• In conclusion, this short-term prospective study offers a proof
of principle of M.I.S.I.T. in patients with a high aesthetic risk
profile.
• The concept based on ridge preservation and contour
augmentation resulted in a favourable clinical and aesthetic
outcome.

CRITICAL EVALUATION
• M.I.S.I.T not followed in all patients  so biased study design
• No CBCT
• No surgical stents used
• Only 1yr follow up

I. Minimally Invasive Surgical Placements of Nonsubmerged Dental
Implants: A Case Series Report, Evaluation of the Surgical
Technique and Complications. Tee YL, J Oral Implantology 2011.
• Minimally invasive surgical implant placement has numerous
advantages over conventional open flap technique.
• A series of cases is described here explaining the use of the
tissue punch with discussion of the complications and
management.
• A sharp probe guided by the surgical template was used to
mark the point for implant placement through the mucosa.
• A bleeding spot thus generated indicated the location over
which the tissue punch would be applied.

• The punch was applied onto the ridge and rotated to ensure a
clean core of soft tissue would be subsequently removed.
• The core of soft tissue was then wrapped in saline soaked
gauze and saved for possible grafting needs after implant
placement.
• A surgical guide was used throughout to ensure a favorable
placement of the implant in 3 dimensions.
• Immediate postoperative radiographs were done to confirm
complete seating.

3 days post 3 months post Final crown

RESULTS:
• All 5 cases exhibited excellent soft-tissue architecture preservation
at 1 week postsurgery with minimal edema, and there were no
complaints of pain during the early postoperative healing period.
• All of the implants achieved successful osseointegration.
• The soft-tissue architecture remained stable with preservation of
adequate attached gingival throughout the healing period of the
implants, contributing to an esthetically pleasing and biologically
sound result after final restorations.

II. Effect of Flapless Surgery on Single Tooth Implants in the
Esthetic Zone: A Randomized Clinical Trial. Bashutski et al, JOP
2013.
• In this randomized, controlled study comparing the flapless and
traditional flap protocol for implant placement, 24 patients
received a single implant in the anterior maxillary region.
• A cone beam computed tomography–aided surgical guide was
used for implant placement surgery for both groups.
• Implants were restored using a onepiece, screwretained ceramic
crown at 3 months. Radiographic and clinical measurements were
assessed at baseline (implant placement) and at 3 (crown
placement), 6, 9, and 15 months.

RESULTS:
• Implant success rate was 92% in both groups.
• Crestal bone levels in the flap group were more apical in
relation to the implant platform than those in the flapless
group for the duration of the study.
• No differences among groups were noted for all other
measurements and both resulted in high success rates.
• A flapless protocol may provide a better shortterm esthetic
result, although there appears to be no longterm advantage.

Journal club on Minimally Invasive Single Implant Treatment (M.I.S.I.T.) based on ridge preservation and contour augmentation in patients with a high aesthetic risk profile.

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Journal club on Minimally Invasive Single Implant Treatment (M.I.S.I.T.) based on ridge preservation and contour augmentation in patients with a high aesthetic risk profile.