DOI: https://doi.org/10.21203/rs.3.rs-2148780/v1
Aim: To evaluate soft tissue aesthetics around immediate dental implants with dentin chips and xenograft in thin buccal bone .
Methodology: 16 patients with non-restorable tooth were recruited in this study for immediate implant placement with augmentation . Patients were randomly assigned into two equal groups; dentin chips group with immediate implant and xenograft group with immediate implant also. Pink aesthetic score are recorded on loading at 6 months & after 1 year of implant insertion according to Vanlıoğlu . Also buccal bone , crestal bone resorption were measured using CBCT on 6 month & 1 year ; implant stability were measured using osstel immediately on implant insertion & before loading and pain is recorded as Numerical rating scale according to Breivik .
Results: In the present study, both groups showed better PES after 6 months and 1 year
P-value = 0.343; P-value = 0.199
nearly same level of crestal bone & buccal bone at 6 months & 1 year
P-value = 0.031; P-value = 0.029
P-value = 0.546; P-value = 0.268
implant stability is better at 6 months and one year P-value = 0.514; P-value = 0.340
and reduction in the post-operative pain within 1 week following implant placement with
but with statistically significant difference within each group and also between both groups.
Conclusions:
The use of autogenous dentin chips proved to be a valid alternative to bone grafting materials to fill the jumping gap in conjunction with immediate implants in the aesthetic zone.
PES, the overall difference between the control and the intervention groups showed no statistical significance
After tooth extraction, host bone resorption and atrophy of alveolar ridge may be observed. Bone resorption occurs specially in incisors and premolar area of jaw in region of thin buccal lamella that may lead to change in contour. Total clinical bone loss height approximately 2-5 mm at first 6 months may be observed in vertical dimension , after 12 months alveolar ridge may lose up to 50 % of its width. (1)
Dentin composes more than 85% of tooth structure and can serve as native bone grafting material. It’s evident that teeth become grafts that gradually and slowly are replaced by bone. (2)
Chemically dentin shows close relationship to bone and showed good osseous regeneration in animals. (1)
Bone and dentin tissue structure are different but ratio of components is similar (mineral 70% , collagen 20% and body fluid 10% by weight).
Dentin after demineralization is mainly composed of type 1 collagen 95% and non-collagenous proteins as growth factors. (3).
Augmentation of extracted sockets with bone is well known and it is the gold standard.
Applying dentin as bone substitutes for augmentation may be useful to become an alternative to allogenic materials. (1)
Study design and registration
The current study was designed as a single-blind, randomized, parallel arms controlled clinical trial, in compliance with the EQUATOR guidelines, with a 1:1 allocation ratio to compare (dentine chips group) to xenograft (control group).
The research protocol was registered on www.clinicaltr ials.gov in May 2018 (NCT03544580). Research protocol, informed consent templates and biological sample collection requests were approved by the Research Ethics Committee, Faculty of Dentistry, Cairo University, in September 2018 (IRB number: 18|09|09).
The study was carried out in compliance with the ethical principles of the Helsinki Declaration for medical research involving human subjects as revised in Seoul, 2008.
Recruitment of participants
The study was conducted at the Faculty of Dentistry, Cairo University, Egypt. Participants were recruited from the outpatient clinic, and study procedures were conducted at the postgraduate periodontology clinic at the Department of Oral Medicine and Periodontology, Faculty of Dentistry, Cairo University.
Potential applicants systemically fit to undergo minor oral surgical procedures free from any systemic diseases or drugs that may contraindicate dental implant therapy.
Non restorable tooth / teeth in maxillary aesthetic zone , Thin facial plate of bone (thin < 2mm) , Free from any pathology , Having periapical bone sufficient to gain primary stability for immediate implant.
Smokers , Pregnant woman and those with Teeth that have to be extracted due to advanced periodontal bone loss , Trauma in aesthetic area or Periapical infection at the site of extraction were excluded.
Sample size determination
Based on a previous study by Arora & Ivanovski 2017 the difference in PES between 2 groups is 1 ± 0.59
Using power 80% and 5% significance level we will need to study 7 in each group this number have been increased to a sample size of 8 in each group to adjust for using a nonparametric test. The number is increased again to 10 in each group to compensate for losses during follow up. Sample size calculation was achieved using PS: Power and Sample Size Calculation software version 3.12 (Vanderbilt Univeristy, Nashville, Tennessee, USA)
Randomization
Extraction sites were randomly assigned to undergo atraumatic extraction then either Dentin chips with immediate implantation (dentin chips group) or Xenograft with immediate implantation (control group) with a 1:1 allocation ratio.
Sequence generation and concealment were carried out by a single investigator (MS) using www.random.org. Allocation was concealed in serially numbered, identical and opaque sealed envelopes. AR was responsible for assigning the allocation of participants into the corresponding study group. All participants were enrolled and equally prepared for the surgical procedure by a single investigator (CH). After tooth extraction and grinding, the intervention allocation was revealed (AR) to the investigator (CH) according to the sequence generated.
Blinding
Study participants were blinded to the treatment received. Blinding of the investigator was not applicable. Outcome’s assessors and biostatistician were blinded. Participants’ identity and their corresponding study group were concealed by assigning an identification number to all data files and reports for the transfer of data to and from assessors.
Preoperative phase
Following inclusion, the medical history of the patients was documented,
teeth of interest were clinically examined, and initial periapical radiographs were taken. Following detailed explanation of the aim of the study, benefits to participants, surgical procedures, harms
and timeline, participants read and undersigned informed consents.
Professional periodontal debridement was performed, and oral hygiene techniques were explained and emphasized. CBCT scan using On Demand 3D is performed to record preoperative ridge width and height measurements and specially crestal bone in aesthetic area.
Surgical procedures
The main operator (C.H) performed all procedures under local anesthesia4 (4% articaine with 1/200 000 adrenaline Solution), using a local infiltration technique.
A 1 capsule loading dose of Antibiotic 875 mg of Amoxicillin and 125 mg of Clavulanic acid tablet (1 g Amoxicillin Clavulanate)5 are given orally to the patient 1 hour before the procedure for insuring aseptic condition for the surgery.
Dentin chips group :
The non-restorable tooth (fig.1& 2) is extracted atraumatically using a periotome
the root is scraped with a curret to clean it from any periodontal ligaments remnants and a bur is used to remove cementum, enamel and pulp or endo filling. (Fig.3)
Dentin is into small blocks, milling it in a bone mill to obtain dentin chips used after implant placement.
Dentin particles is immersed in 70 % ethanol (El-Gomhouria CO. Egypt) in a sterile container for 10 minutes to remove any soft tissue remnants, bacteria and smear layer (defatting and sterilization).(Fig.4)
Tooth particles is demineralized using HCL (El-Gomhouria CO. Egypt) for 20 minutes to expose the dentin organic matrix. (Fig 5)
The bacteria-free particulate dentin is washed with phosphate buffered saline (El-Gomhouria CO. Egypt) twice for 5 minutes to restore the pH balance (Fig 6 & 7)
Then osteotomy site is be done using appropriate drill sizes
A paralling pin is applied to assure the implant future position behind the dentin chips (Fig.8) and an periapical x-ray is taken
The implant ( Neobiotech USA. Inc., korea ) is inserted in place submerged 2mm under bone crest flapless technique and also dentin chips in jumping gap (Fig.9) and another periapical is then taken . we always use a small diameter of implant to leave a great space for graft
Control group:
Same as dentin chips group, but we used xenograft ( Bio-Oss®.) not dentin chips in jumping gap between implant and buccal bone (Fig.12-17)
Postoperative care and follow-up
Post-surgically patients is prescribed for cold therapy immediately after the surgery. 1 g Amoxicillin Clavulanate (875 mg of Amoxicillin and 125 mg of Clavulanic acid tablet) twice daily for 7 days, anti-inflammatory tablet (50mg Diclofenac) (Cataflam 50mg) three times daily and Povidone Iodine (1%) mouthwash (Betadine mouthwash) twice daily are prescribed.
Immediately before and after the surgery standardized radiographic is performed indicating the position of the dentin chips and amount of buccal bone resorption width gain with the level of crestal bone. Again a CBCT is taken after 6 and 12 months to insure that dentin chips is replaced by bone or not and no resorption is found. Also pain scales is assessed during such appointment. ( Fig.16,17)
Appointments is assigned once weekly for the next 2 weeks to assess the pain and swelling and collection of the assessment records at the end of 2 weeks
Outcomes :
Pink aesthetic score
Is measured using photos preoperatively , 6 months & 1 year as follow
and score is given of 2, 1, or 0 is assigned to each of five PES parameters with maximum total PES of 10 is possible.
Buccal bone resorption , crestal bone
Both are measured on CBCT preoperatively, 6 months & 1 year as follow
Buccal bone : in middle of root before extraction & in middle of implant after placement as shown in picture
Crestal bone :
Is measured from bone crest till end of root before extraction & after extraction from the crest to end of implant
Implant stability
Using osstel
Pain
Using a score
Groups characteristics
Participants were recruited, treated and followed up between July 2018 and January 2020. All participants in both groups completed the follow-up period and were included in the analysis.
Two failed implants of our patients were observed.
Sixteen participants with single rooted-teeth indicated for extraction were randomly allocated into the test (DC with immediate implant) and control group (xenograft with immediate implant ) with 8 participants per group.
Reasons for extraction were advanced caries or fracture of teeth beyond restoration.
The dentin chips group included 5 females and 3 males with mean age of 34.4 ± 11.3 years, while the control group included 0 male and 8 females with mean age of 37.1 ± 7.5 years.
Regarding extracted teeth distribution, the dentin chips group included 8 maxillaries with 6 sites in the anterior teeth segment and 2 in the premolar segment.
For the control group, 6 maxillaries with 0 anterior and 8 premolar extraction sites. There was no statistically significant difference between mean age values in the two groups. Also no statistically significant difference was found between gender distributions in the two groups.
Pink Esthetic Score (PES)
Comparison between the groups
Pre-operatively, after 6 as well as 12 months; there was no statistically significant difference between PES scores in the two groups (P-value = 0.227, Effect size = 0.574), (P-value = 0.343, Effect size = 0.458) and (P-value = 0.199, Effect size = 0.544). (Table.2)
Changes within each group
In both groups; there was a statistically significant change in median PES scores by time (P-value = 0.010, Effect size = 0.581) and (P-value = 0.003, Effect size = 0.74), respectively. Pair-wise comparisons between time periods revealed that there was a statistically significant decrease in median PES scores after 6 months followed by non-statistically significant change from 6 to 12 months. The median PES score after 12 months showed statistically significantly lower median score than pre-operative score. (Fig.18)
Buccal bone resorption (mm)
Comparison between the groups
After 6 as well as 12 months; there was no statistically significant difference between buccal boe resorption in the two groups (P-value = 0.546, Effect size = 0.292) and (P-value = 0.268, Effect size = 0.486). (Table .3)
Changes within each group
In both groups; there was no statistically significant change in median buccal bone resorption by time (P-value = 0.071, Effect size = 1.661) and (P-value = 0.293, Effect size = 0.801), respectively. (Fig.19)
Crestal bone loss (mm)
Comparison between the groups
After 6 as well as 12 months; intervention group showed statistically significantly lower median crestal bone loss than control group (P-value = 0.031, Effect size = 1.277) and (P-value = 0.029, Effect size = 1.277), respectively. (Table .4)
Changes within each group
In both groups; there was a statistically significant decrease in median crestal bone loss after 12 months (P-value = 0.021, Effect size = 3.955) and (P-value = 0.012, Effect size = 3.932), respectively. (Fig.20)
Implant stability
Comparison between the groups
After 6 as well as 12 months; there was no statistically significant difference between mean implant stability values in the two groups (P-value = 0.514, Effect size = 0.036) and (P-value = 0.340, Effect size = 0.076), respectively.
Changes within each group
In both groups; there was a statistically significant increase in mean implant stability value on loading (P-value <0.001, Effect size = 0.893) and (P-value <0.001, Effect size = 0.862), respectively. (Fig.21)
Pain (VAS) scores
Comparison between the groups
After one day, two, three, four, five, six as well as seven days; there was no statistically significant difference between pain (VAS) scores in the two groups (P-value = 0.436, Effect size = 0.374), (P-value = 0.436, Effect size = 0.374), (P-value = 1, Effect size = 0), (P-value = 1, Effect size = 0), (P-value = 0.903, Effect size = 0.053), (P-value = 0.136, Effect size = 0.758) and (P-value = 0.268, Effect size = 0.486), respectively.
Changes within each group
In intervention group; there was a statistically significant change in median VAS scores by time (P-value <0.001, Effect size = 0.981). Pair-wise comparisons between time periods revealed that there was a statistically significant decrease in median VAS scores at day 2, from day 2 to 3, 3 to 4, 4 to 5, 5 to 6 as well as 6 to day 7. In control group; there was a statistically significant change in median VAS scores by time (P-value <0.001, Effect size = 0.942). Pair-wise comparisons between time periods revealed that there was a statistically significant decrease in median VAS scores at day 2, from day 2 to 3, 3 to 4 as well as from day 4 to day 5. From day 5 to day 6, there was no statistically significant change in median pain scores followed by a statistically significant decrease in median pain score at day 7. (Fig.22)
Harms
Any temporary or permanent adverse effect will be recorded and documented.
The present study aimed to compare the autogenous demineralized dentin graft (ADDG) versus xenograft (Bioss) for their effect on PES after 6 months and one year also on Buccal bone resorption, crestal bone volumetric changes assessed by 3D cone beam computed tomography (CBCT) & Implant stability using osstel .
To minimize confounders, different measures for the selection of participants have been taken in the study. Smokers were excluded due to the fact that smoking has unfavorable effects on bone healing, not only it adversely affects host cells function and causes alternations to the inflammatory response, but also it reduces the blood supply which leads to decrease in tissue perfusion and ischemia and in turn, negatively affects healing processes following tooth extraction (5). Clinically, smoking can increase the post-extraction alveolar crest loss by 0.5 mm (6). Pregnant females were excluded to avoid the teratogenic effect of high radiation exposure when performing CBCT scans (7).
Some metabolic diseases such as diabetes or hyperthyroidism as well as systemic medications such as chemotherapy or bisphosphonates are further known to affect bone remodeling (6). Accordingly, patients reporting having any of these conditions were excluded.
only patients over 18 years were included to be able to provide informed consent and to avoid the effect of bone growth and passive eruption of teeth on the quantitative measurements.
In addition to the above-mentioned general exclusion criteria, local site-specific criteria have been set as well. Exclusion of molars was done due to the fact that bone quality as well as the size and configuration of molar sockets are different than single-rooted teeth and consequently, healing time and processes are considered dissimilar (8), (9).
Damaged extraction sockets are generally believed not to be suitable for supporting graft material and require wall replacement by block graft (10) and therefore, such defects were not included. Teeth with root canal filling were not used as the filling material incorporated into the graft can act as a foreign body or affect local healing (2)
Finally, local infection at the site of extraction is known to delay healing, the high acidity is due to inflammation and bacterial byproducts can cause graft particle to dissolve via cell-mediated process or solution-mediated process (11) and hence no infected site was included.
For the surgical technique used in this study, the flapless approach was chosen since flap elevation is known to cause crestal bone resorption due to the transient deprivation of osteogenic cells and blood supply (12) In a systematic review it was concluded that leaving the periosteum undisturbed through a flapless approach shows less alveolar bone height and width resorption in comparison to flap elevation, making it the recommended approach to preserve the bone crest (9)
Choice of Periotomes was made as they serve the goal of atraumatic extraction by cutting periodontal ligament attachment along the root surface thus decreasing the tooth resistance to extraction forces. They also minimally dilate the extraction socket thus initiating tooth luxation and permitting an easier path of removal and at the same time, avoiding trauma to the alveolar process and the adjacent teeth.(13)
When compared to the conventional forceps, periotomes required more surgical time but resulted in less buccal bone fracture, less root fracture, less soft tissue laceration, and less postoperative pain (7).
After extraction, teeth were cleaned from caries it can act as a bacterial reservoir, restorations were removed to avoid foreign body reaction or inflammatory effect to the healing site and soft tissue attachment and their insertion in cementum were removed as they hinder the access of disinfectant or demineralizing agents to the tooth surface. The hand-driven bone mill is a tool used to grind autogenous bone for various applications. Its use for chairside preparation of tooth-bone graft (TBG) has been reported ((1) (14) & (13)). Unlike the bulky and expensive automated mills, it is a convenient and available tool that can be used in everyday clinical scenarios.
The Hydrochloric acid (HCl) was used for the preparation of the ADDG as it is one of the strongest demineralizing agents, it has germicidal effect and in the same time, it does not cause denaturation of collagen fibrils in the dentin matrix, hereby it is the most commonly employed acid in clinical use (16). The graft particles were immersed in 0.6N HCl for 30 minutes as recommended by (17)which reported that there was a significant difference concerning graft mineral content and crystalline structure between 10 minutes and 30 minutes of acid application, but there was not any difference when increasing the demineralized period beyond that. The same acid and time application was experimented in ARP clinically by (18) and showed to be an effective processing technique for ADDG.
Asepsis is essential for adequate healing ; bacterial virulence factors can cause fibrinolysis and disintegration of the formed blood clot, raise the local cytokines that can cause local matrix degradation and hence compromising the healing outcomes.(4). It is a common practice then to prescribe antibiotics post-operatively to avert any negative effects of bacteria during the blood clot phase till the beginning of granulation tissue formation which is less impervious and followed by epithelial closure (19) and therefore; antibiotics were prescribed during the early phase of healing for all participants.
Participants were advised to stop using the toothbrush and chewing at the surgical site .They were also advised to follow a soft and cold diet to avoid any undesired trauma to the surgical site, ice packs surgical site, Chlorhexidine mouthwash was used and it was used as it has been proved to be antiseptic, reduce biofilm buildup and gingival inflammation following dental surgeries (20)
Esthetic-outcome assessment has been an emerging area of focus in implant dentistry. To sustain an esthetic appearance, it is essential to consider the characteristics of the surrounding soft and hard tissues. (21) therefore The pink esthetic score (PES) was used to evaluate the esthetic outcomes with the clinical photographs before the treatment and after the follow-up period. The PES includes seven variables (the mesial papilla, the distal papilla, the midfacial level, the midfacial contour, the alveolar process deficiency, the soft tissue color, and the soft tissue texture), and was assessed by using a 0-1-2 score, with 0 = lowest score, and 14 = highest score. (22)
The PES is a tool for reproducibly evaluating the esthetic appearance of the soft tissue around single-tooth implant crowns. (22)
Pink esthetic in our study is statistically non-significant between immediate implants with dentin chips & immediate implant with xenograft in 6 months & 12 months.
To our knowledge there has not been any published comparison between dentin chips and other grafts with immediate implants.
A significant decrease of PES was observed in each group at 6 and 12 months with no clinical relevant which is inconsistent with (23)who said that esthetic outcome of soft tissue around the single-tooth implant had improved significantly at follow-up compared with baseline according to PES assessment. As that may be explained by immediate restoration of immediate implants in his study. His results suggested that the potential for significant changes in soft-tissue levels after restorative therapy needs to be considered for single-implant therapy in the anterior maxilla.
Crestal bone loss showed statistically significant more bone loss from 0–6 months than from 6–12 months in the two groups more over statistically significant bone loss was observed in control group than interventional group which is inconsistent with (24)Showed that implants placed in post-extraction sockets augmented with DFDBA exhibited minimal marginal bone loss similar to implants placed in native bone.
Our results is in contrast to (25) reported that No matter using autogenous tooth bone or xenogenous bone, the horizontal bone loss at the first or the latter 6 months was almost the same in the level 0 mm, 3mm and 6mm of the implant facial part and No matter what the follow-up period is, and bone graft material used, the horizontal bone loss at the level of 6mm was much less than the level of 0mm and 3mm in the facial of the implant. All implants achieved the success criteria without (24) claimed that grafting of extraction sockets is beneficial in terms of limiting the dimensional changes of the alveolar ridge following tooth/teeth extraction.
Implant stability in our study increased at 6 months than upon insertion which may be consistent with systematic review of (26) who claimed that primary implant stability can be influenced by the macro design of dental implants, and roughness enhancing surface treatments can increase ISQ values in later osseointegration phases, improving secondary implant stability. Primary implant stability is lesser with lower bone density and may be enhanced by the utilization of thinner drills (under preparation) or osteotomes when the bone density is inadequate.
Bajaj G et al.2017 (27)claimed that primary and secondary stability of immediately loaded group comparison has shown that there was a significant statistical difference and early loaded group comparison has shown that there was the significant statistical difference. But when differences of primary and secondary stability of immediate loaded and early loaded group comparison have shown that after after osseointegration there is no difference in stability.
But we have an implant failed after 1 month due to trauma patient have faced in intervention
& another one failed after 6 months before loading may of unknown
Brisman et al, 2001(28) reported that even asymptomatic endodontically treated teeth with a normal periapical radiographic appearance could be the cause of an implant failure. They also suggested that microorganisms may persist, even though the endodontic treatment is considered radiographically successful, because of inadequate obturation or an incomplete seal.
In our present study pain (VAS) score successfully decrease day to day.
A study was conducted in past in implant surgery and found that the female gender was significantly associated with pain (29), and another study claine that women had a significantly higher anxiety level than men, and that this again led to more pain (30). Accordingly, in our study, women experienced more pain than men on the second postoperative day. However, other studies found no difference between genders in pain perception (31). In many experimental studies on pain, though, women reported more severe pain and a longer duration of pain than men .(32)
In our study we had a success rate of almost 94% which nearly the same as (33) results was a higher failure rate was found for the implants in the posterior region of the maxilla, and when periodontitis was cited as a reason for tooth extraction. The overall success rates were 93.4% and 95.7% in the immediate and delayed implant placement groups, respectively, after a 2-year follow-up. No obvious relationship of success rate was observed with the implant placement method, cause of tooth extraction, and implants' position.
With all of the advantages of the ATG, it also exhibits limitations. The process of chairside preparation includes cleaning, grinding and disinfection which requires time and effort. As an autogenous graft, it is only available in limited quantity. It requires the extraction of a tooth for graft preparation and hence cannot be used in individuals that do not have any teeth indicated for extraction or in completely edentulous subjects. A possible solution to this problem can be done by using tooth derived graft materials obtained from allogenic sources but the practice of using allogenic tooth-bone graft has been only investigated in a handful of clinical studies with concerns about effective preparation and donors screening for commercial release. (34)
(35) they concluded that AWTG or ADDG employed in ARP is equally effective at reducing dimensional losses after 6 months, with no adverse effects. Histologically, both grafts were biocompatible and osteoconductive, with ADDG seeming to exert higher osteoinductive properties. Chairside preparation and application of ATG are feasible, cost-effective and can provide an alternative source to commercially available grafting materials. Further investigations are needed to optimize the two graft preparation techniques and explore and compare their effects in different clinical scenarios in the oral cavity.
1. The use of autogenous dentin chips proved to be a valid alternative to bone grafting materials to fill the jumping gap in conjunction with immediate implants in the aesthetic zone.
2. The use of slowly resorbing grafting substitutes as said by Kim et al. 2010 simultaneously with immediate implants helped to preserve the contour of the facial bone plate in the aesthetic zone.
3. Autogenous dentin chips when used with immediate implants decrease the crestal bone loss more than Bio-Oss®.
4. Although the total time for the procedure in the intervention group was slightly longer than that for the control group, no statistical significance existed between both groups regarding the pain reported by the patients enrolled in each group.
5. Regarding the (PES), the overall difference between the control and the intervention groups showed no statistical significance.
Protocol Registration:
Study was registered on https://clinicaltrials.gov/
Funding: Self-funding
ACKNOWLEDGMENTS
The authors would like to sincerely thank Dr. Abdullah Mattar for his support during the clinical evaluation .This study was self funded
CONFLICT OF INTEREST
All authors state explicitly that they have no conflicts of interest in connection with this article.
all data sets used and/or analyzed during the current study are available from the corresponding author on reasonable request".
• autogenous demineralized dentin graft
• alveolar ridge preservation
• autogenous dentin matrix
• autogenous whole tooth graft
• Cherine Hamada
• demineralized freeze dried bone allograft
• Pink esthetic score
• tooth bone graft