Immediate vs Delayed Loading of Single Tooth Implants
Condition: Implant Complication
Study type: Interventional

Summary: 
      Previous studies have shown high success rates of immediately loaded implants on par with
      conventionally loaded implants (DL), while a few studies have also reported failure rates.
      Various studies can be found in the English literature comparing IL to DL protocol, few of
      which used the flapless approach while few used cylindrical implants or were confined to
      maxillary anterior region. Furthermore, a perusal of literature revealed no study which used
      RVG for radiographic evaluation and evaluated the morbidity at the implant site in normal
      healthy adult population. Hence this study would help determine whether the IL protocol is on
      par with DL protocol, so as to reduce patient waiting time, prevent space closure and provide
      early patient satisfaction from an aesthetic stand point.
    

Detailed description: 
      Oral implants have become a reliable alternative to replace lost teeth as they have a very
      high survival rate. The survival rate of dental implants has improved significantly over the
      years and is often estimated to be above 90%. They support dental prosthesis, overdentures,
      crowns and bridges to restore oral function and aesthetics that the insertion of dental
      implants in bone has become one of the routine procedures in dental set up. It needs bone
      exposure which is associated with some amount of bone loss.

      Osseointegrated implants are placed traditionally following a two stage protocol, wherein
      implants are left to heal unloaded for 3-4 months in mandible and 6-8 months in maxilla.
      Successful osseointegrated implants are anchored directly to bone. The presence of highly
      mineralized compact mature bone with many Haversian canals have been shown in the microscopy
      of retrieved implants from man and experimental animals. Regions of fibrous tissue
      interposition are not found. The newly formed bone has features of normality with marrow
      spaces filled with blood vessels.

      However, in the presence of movement, a soft tissue interface may encapsulate the implant,
      causing its failure, that is, formation of a fibrous connective tissue rather than bone at
      the implant bone interface. A similar effect has been reported to occur in bone fractures
      that had been inadequately immobilized, resulting in a non-union of the fractured segments.

      To minimize this, many clinicians advocate keeping the implants unloaded during the healing
      period. This traditional approach takes a longer treatment time and requires a second
      surgical intervention for connection of abutment to implant.

      It would be beneficial to reduce the treatment period without affecting the success rate of
      the implants. Due to advancements in oral implantology, such as implant design and titanium
      surfaces treatment, the immediate loading concept has gained popularity by offering shortened
      treatment time, trauma reduction, decreased patient's anxiety, discomfort, improvement in
      function and esthetics. This treatment option also aims at maintenance of the hard and soft
      tissues and reducing the waiting period. Nowadays immediate and early loaded implants are
      becoming increasingly common due to the various benefits for patients.

      Exact indication and considerations for the immediate loading protocol were defined for the
      first time in 2002 at the World Congress Consensus Meeting in Barcelona according to which
      adequate implant stability, controlled occlusal loads for full arch cases, non-occlusal loads
      for short span bridges and single teeth replacements are important considerations for a
      successful outcomes. According to this meeting, immediate functional (or occlusal) loading is
      defined in the treatment protocol, that is, when implants have been placed in the bone and
      have been restored with the use of restorations with occlusal contacts within 3-4 days of
      surgery, and immediate non-functional loading (IL) as restorations without occlusal contacts.

      Occasionally immediately loaded implants have been associated with increased failure rates.
      it is therefore important to evaluate whether predictable results can be obtained according
      to the different loading protocols during replacement of a single tooth by implants.

      The implant failure under immediate loading compared to delayed loading (DL) was evaluated in
      various randomized clinical trials. For the immediate loading group, the implant failure rate
      was 2.87% compared to 1.8% in the delayed loading group. Overall, there was no statistical
      significance in the difference in implant failure rate between these two groups.

      Previous studies performed by Degidi et al. and Margossian et al. showed high success rates
      of immediately loaded implants placed in comparison with conventionally loaded implants.
      Recent studies performed by Merli et al and Romanos et al also proved that the success rate
      of the immediately loaded implants were on par, if not higher that the early or delayed
      loading protocols.

      Various studies can be found in the English literature comparing IL to DL protocol, few of
      which used the flapless approach while few used cylindrical implants or were confined to
      maxillary anterior region. Furthermore, a perusal of literature revealed no study which used
      RVG for radiographic evaluation and evaluated the morbidity at the implant site in normal
      healthy adult population. Hence this study would help determine whether the IL protocol is on
      par with DL protocol, so as to reduce patient waiting time, prevent space closure and provide
      early patient satisfaction from an aesthetic stand point.

      Therefore the purpose of the present study is to compare the results of immediate and delayed
      loading protocols. The null hypothesis is that there would be no difference in success rates,
      complications and peri-implant marginal bone level changes between the procedures, against
      the alternative hypothesis of a difference.

      MATERIALS AND METHOD This study will be conducted in Department of Periodontics and Oral
      Implantology, Post Graduate Institute of Dental Sciences (PGIDS), Rohtak, Haryana.

      STUDY POPULATION AND DESIGN A minimum of 24 individuals will be recruited from outpatient
      department of PGIDS, Rohtak and divided equally into test and control groups.

      DISTRIBUTION OF SAMPLES Systemically healthy individuals will be divided randomly in two
      groups (control group & test group)

        1. Control group (CG) - The implant will be loaded after 3-4 months of placement
           (Conventional/Delayed Loading)

        2. Test group (TG) - The implant will be loaded non-occlusally within 3-4 days of placement
           (Immediate Loading)

      Methodology The study will be conducted in two phases-

        1. Pre surgical preparations:-which will include

             -  Prior to implant preparation all patients will undergo a session of oral hygiene
                instructions and professionally delivered debridement procedures.

             -  The patients will be subjected to complete hemogram analysis including platelet
                count, hemoglobin (Hb), bleeding time (BT), clotting time (CT), total leucocytes
                count (TLC), and differential leucocytes count (TLC).

        2. Surgical preparations:-prior to surgery, 5% povidone iodine solution will be used for
           extra oral and intra oral asepsis.

      Osteotomy procedure: - After administration of adequate amount of local anesthesia, a sharp
      full thickness incision will be given for elevation of a muco-periosteal flap at the middle
      of the crest followed by a crevicular incision on the adjacent teeth. After elevation of a
      full thickness flap, any sharp edges at the crest of the ridge will be smoothened. The crest
      should be at least 2mm wider than the diameter of the implant being used. The osteotomy site
      will be marked with a round bur and penetrate the cortex with a lanceolated drill. A 2mm
      twist drill will be used till the appropriate depth reference line- (drill speed 2000rpm).
      The orientation of the osteotomy can be checked using a direction indicator and taking an
      X-Ray/RVG with the indicator in place. Any changes in the direction, if required, can be made
      at this point. Sequentially the drills of increasing diameter will be used depending on the
      size of the implant selected observing anatomical landmarks (drill speed 800rpm). The final
      drill should be 0.5mm less than the implant diameter. Implant will be inserted by setting the
      torque 20-45Ncm, depending on the bone quality. Once the implant is fully seated, the implant
      driver will be pulled free from the implant connect the implant driver to the ratchet.
      X-ray/RVG will be taken to see the final position of the implant. Before adapting the soft
      tissue, the surgical site will be irrigated with normal saline to flush out any debris.

      For the immediate loading (test) group, impression copings will be placed and impression made
      with addition silicone material and will be sent to lab for provisional restoration
      fabrication. The provisional restorations will be placed within 3-4 days of implant
      placement. The occlusal surface of the provisional restorations will be ground in order to
      avoid any contact with the opposite dentition in static and dynamic analysis. They will be
      recalled after 3-4 months for final prosthesis placement.

      For the conventional loading (control) group, the flap will be sutured with a direct suture
      technique using 3-0 silk suture material. After one week patient will be recalled for suture
      removal. After three to four months of healing, radiographs will be taken to evaluate the
      mesial and distal crestal bone -implant interface before the abutment post is added to
      implant body. After this the cover screw will be removed after exposing it through the mucosa
      and low profile healing cap will be inserted. After 1-2 weeks of healing, the healing cap
      will be removed and transfer coping will be attached to implant. Impression will be made
      using Addition silicon impression material. Implant analogue will seated into coping in the
      impression and cast will be poured.

      Impression and abutment will be sent to lab for fabrication of prosthesis. Prosthesis will be
      cemented using glass ionomer cement.

      All the patients will be evaluated by Intra-oral radiographs and soft tissue parameters like
      Plaque Index, Gingival Index, Bleeding on Probing, Pocket Depth, Clinical Attachment Loss,
      Tooth mobility, Implant site morbidity. Data will be recorded at the time of implant
      placement and at 8 weeks, 4 months and 7 months of follow up primarily and total follow up
      period of 4 years.

      Follow up and success criteria:- Assessments will be made at the time of placement of the
      implant (baseline), at 8 weeks, at 4 months and 7 months after placement of the implant and
      followed upto 4 years.

      CLINICAL PARAMETERS based on 1st European Workshop on Periodontology

        -  For implant site and adjacent neighboring teeth site.

        -  Plaque index (PI) - SILNESS&LOE

        -  Bleeding on probing (BOP)

        -  Tooth mobility will be quantified by perio test

        -  Pocket probing depth (PPD)

        -  Clinical attachment level (CAL)

        -  Post-operative morbidity in terms of swelling, bruising, wound dehiscence, pus discharge
           will be observed clinically.

        -  Radiographic marginal bone loss/radiolucency will be observed by intraoral periapical
           x-ray/RVG using parallel cone technique and measured by Image J analysis.

        -  Periodontal probe (university of north carolina- UNC 15) probe will be used for
           recording periodontal parameters.
    

Intervention name(s): Conventional/Delayed Loading; Immediate Loading
Intervention type(s): Procedure; Procedure
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment