Immediate versus early loading of flapless placed dental implants: A systematic review Lin Xu, BDS, MDSc,a Xiaodong Wang, BDS, MDSc,b Qin Zhang, BDS,c Wen Yang, BDS,d Wenjun Zhu, BDS, MDSc,e and Ke Zhao, BDS, PhDf Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China Statement of problem. The flapless implant technique is a predictable procedure with several advantages and a high overall implant survival rate. Immediate loading and early loading have been widely used in dental implant therapies and provide improved esthetics, with enhanced function and comfort. However, the scientific support for immediate or early loading approaches for flapless-placed dental implants is unclear. Purpose. The purpose of this review was to systematically assess the effectiveness and safety of the immediate versus early loading of dental implants with flapless placement. Material and methods. The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CNKI database, VIP database, WANFANG Database, and World Health Organization International Clinical Trials Registry Platform Search Portal were searched (up to October 2012). The systematic review included clinical randomized controlled trials that compared immediate with early loading of flapless-placed dental implants to replace missing teeth in adult participants who were partially or completely edentulous. The selection of included studies, data extraction, and assessment of the quality of the studies and evidence were conducted independently by 2 reviewers. Results. Six articles that reported on 4 randomized controlled trials that involved 180 selected participants were included. The implant failure rate was from 0.0% to 3.3% in both immediate and early loading groups with flapless implantation. No statistically significant differences were found in implant failure rates, periimplant marginal bone-level changes, or complications between the 2 groups. More participants preferred immediate loading rather than waiting for nearly 2 months. Conclusions. Within the limitation of needing additional high-quality evidence, immediate and early loading of dental implants after flapless placement both demonstrated an acceptable short- to medium-term survival rate. Immediate loading seems more acceptable because of the time benefit. (J Prosthet Dent 2014;-:---)

Clinical Implications Immediate or early loading of dental implants placed by using the flapless procedure is widely used for replacing missing teeth due to its reduction of discomfort, treatment time, and costs. This study revealed that the immediate loading option seems more acceptable because of the time benefit. Tooth loss of any kind usually leads to problems of esthetics, comfort, and function.1,2 Currently, implantsupported dental rehabilitation has a

Resident, Department of Prosthodontics. Resident, Department of Prosthodontics. c Resident, Department of Prosthodontics. d Resident, Department of Prosthodontics. e Resident, Department of Prosthodontics. f Professor, Department of Prosthodontics. b

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been a common treatment option, with favorable survival rates, for replacing missing teeth and improving the quality of life of patients who are completely

and partially edentulous.3,4 The flapless implant surgery technique is an alternative and minimally invasive technique that does not require soft-tissue flaps

2

Volume and suturing. This technique has gained popularity since its introduction in 2000.5-7 The flapless approach has several advantages over conventional flap elevation, including the preservation of hard tissues; maintenance of vascular supply; decreased surgical procedure time; lower intensity; and reduction of postoperative complications, for example, pain, swelling, infection, necrosis, or dehiscence.5,8-13 Furthermore, the available data indicate that the flapless technique is an effective and predictable procedure with high overall implant survival rates.6,8-10 The success rate has been reported to be 98.6% in prospective cohort studies, whereas retrospective and case studies have indicated survival rates of 95.9%.8 In addition, the survival rate of the flapless technique is comparable with the conventional surgical protocol when performed with patients who have an adequate quantity of bone.10,14 Immediate loading (IL) and early loading (EL) has been widely used in implant therapies, particularly in mandibles with good bone quality. The protocols provide good esthetics, enhanced function, and almost immediate comfort, and have a favorable implant survival rate.15-20 IL has been defined as the placement of an interim prosthesis within 72 hours of implant placement,21,22 whereas EL has been defined as the loading of the implants after a 6-week to 2-month healing period.20,22 Esposito et al17 indicated that both IL and EL implants were successful in selected patients, with no statistically significant differences in the outcomes. However, the results of that study suggested a trend that IL implants might fail more often than conventionally loaded implants but less commonly than EL implants. Patients are assumed to prefer the delivery of a functional and esthetic prosthesis on the same day as implant placement, which reduces discomfort, treatment time, and costs; flapless surgery, combined with IL or EL to replace missing teeth, is then considered. Some studies have demonstrated that this procedure could provide excellent

clinical results.23-27 The conclusions of a 3-year follow-up randomized controlled trial (RCT) determined that there were no statistically significant differences in failure rates and bone levels between IL and EL implants with the flapless approach.28 This result has wide consensus in other RCT studies.24,29 Nevertheless, Cannizzaro et al30 showed more failed implants in the flapless placement and EL group than in the flapless placement and IL group. Some studies revealed that complications developed more frequently in the flapless placement and IL group than in the EL group.24,28,29 When considering periimplant bone changes, Moon et al31 observed that the bone formation rate was high and that a degree of bone contact was indicated for IL and EL. Currently, the recommendation for IL or EL approaches for flapless placed implants is still premature. Reviews have been published on the topic of flapless surgery or different loading protocols17,32-34; however, no study has focused on the flapless technique with IL or EL. Therefore, the objective of this study was to conduct a systematic review to evaluate the effectiveness and safety of IL (within 3 days) versus EL (after 6 weeks to 2 months) of dental implants placed by using the flapless procedure for replacing missing teeth and to assess the quality of retrieved evidence and the strength of recommendations by using the Grades of Recommendations Assessment, Development and Evaluation (GRADE) system.

MATERIAL AND METHODS This review used RCTs, which compared the efficacy of IL with EL of dental restorations supported by flapless placed implants. Studies with participants who were either partially or completely edentulous, different definitions of IL or EL, and all types of implants and implant-supported prostheses were included. The primary outcomes of this review consisted of implant failure (the presence of any mobility of implants and/or infection

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that dictates implant removal) and periimplant marginal bone-level changes. The secondary outcomes consisted of patient satisfaction and biologic or prosthetic complications. Two reviewers (L.X., X.W.) independently searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL) (accessed October 2012), MEDLINE (1966-2012), EMBASE (1980-2012), CNKI database (1976-2012), VIP database (Chongqing VIP information Co., Ltd.) (1986-2012), and WANFANG Database (Beijing Wanfang Data Co., Ltd.) (1994-2012). A detailed search strategy was prepared for each database. Search terms were the following: flapless, incisionless invasive, minimally invasive, implant*, immediate*, early. In addition, the World Health Organization International Clinical Trials Registry Platform Search Portal for ongoing studies also was retrieved. To increase the yield of relative studies, the references of all identified studies were searched manually. Initially, 2 review authors independently scanned all titles and abstracts of the potential studies identified through the electronic searches. The full-text articles were analyzed when the title or abstracts indicated that the eligibility criteria were fulfilled. Two reviewers (L.X., X.W.) independently extracted the data of included studies by using a special data collection form. Any discrepancy was resolved by discussion, and, if resolutions were impossible, then a third reviewer (K.Z.) was consulted. When necessary, the original investigator (L.X. or X.W.) was contacted for further clarification of relevant information. The risk of bias for each included study was assessed independently by 2 review authors (L.X., X.W.) according to the recommended approach suggested by the Cochrane Collaboration, which included the following specific aspects: sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting bias, and other sources of bias. When the possibility of a reporting bias existed, the original study investigators were contacted to provide further outcome

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data, if possible. If the study protocol was available, then its outcomes were compared with the published article; if not, then the outcomes listed in the methods section of an article and reported in the results section were compared. For continuous data, outcomes were expressed as the mean difference (MD) if measured in the same scale or as the standardized MD if measured in different methods with a calculated 95% confidence interval (CI). For dichotomous data, a risk ratio or odds ratio (OR) with a 95% CI was used. The I2 statistic was used to quantify the statistical heterogeneity among the studies for all outcomes. For an I2 of not more than 50%, a fixed-effect model was performed regarding no or moderate heterogeneity. When substantial heterogeneity (I2 > 50%) was presented, possible explanations were explored, and a random-effects metaanalysis was performed or a descriptive analysis was performed. To test the

reliability of evidence, sensitivity analysis was performed by comparing the difference between a fixed-effect model and a random-effects model. The subgroup analysis was performed for the following groups: different follow-up time and different types of prosthesis.

RESULTS There were 62 references that were identified by following the search strategies. Title and abstract analyses obtained 7 potentially relevant articles (Fig. 1).22-25,28-30 Full-text analyses indicated 3 articles that discussed an identical trial published by the same investigator22,23,28; the preliminary article was excluded because the data were reported in 1 of the other 2 included articles,22,23,28 which discussed different follow-up periods. Overall, 6 articles about 4 trials were included in this review (Table I).23-25,28-30 All of the included studies were RCTs with a single center, parallel design. All of the

included trials were conducted in Italy. The 4 studies involved 180 participants (77 men and 103 women), with ages between 18 and 80 years. Sixty-four of the participants were smokers. The participants were recruited and treated in private dental clinics in Italy. In 2 trials, the participants were required to have bone volumes in which implants of no less than 3.7 mm in diameter and 10 mm in length could be placed.29,30 The other 2 trials included participants with at least 5.5 mm of bone at the implant sites: one of the studies required bone that allowed placement of 6.5-mm-long implants,24,25 whereas the other study required the placement of implants at least 9.5-mm long.23,28 In all 4 of the trials, the participants were randomly allocated to 2 groups: the test group was loaded immediately after flapless implantation, and the control group was EL after flapless implantation procedures. Two trials used definitive metal ceramic crowns.23-25,28 One

Initial electronic search results: CENTRAL (n=6); PubMed (n=14); EMBASE (n=13); CNKI (n=16); WANFANG (n=3); VIP (n=10) 19 duplicates removed 43 potentially relevant records Non dental implants related (n=17) Not clinical trials (n=4) Retrospective studies (n=2) Trials without random or control (n=4) Not immediately versus early loading (n=8) Not flapless implantation (n=1)

No articles added by manual search

7 potentially appropriate records to be obtained full texts 1 article excluded for its datum were parts of results in another article 6 articles included

1 Search and selection flow of articles.

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Table I.

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Characteristics of included studies

Study, y

Method

Participants

Interventions

Outcomes

Cannizzaro et al,29 2008 (spring)

RCT, parallel design

(1) Total no., 60 (IL, (1) Test group: flapless implantation and IL (the same day as placement); (2) control group: M/F¼11/19; EL, flapless implantation and EL (6 wk after M/F¼14/16); (2) age placement); (3) no. inserted implants: IL/EL range, 36-80 y; (3) 60/60; (4) prosthesis: mandibular bardiagnosis: retained overdentures; (5) implants: tapered mandibular SwissPlus; (6) time of follow-up: 1 y; completely (7) dropouts: none edentulous arches

Implant failure, prosthesis failure, patient satisfaction, complications

Cannizzaro et al,30 2008 (summer)

RCT, parallel design

(1) Total no. 30 (IL: M/F¼8/7; EL: M/ F¼7/8); (2) age range, 42-75 y; (3) diagnosis: maxillary completely edentulous arches

(1) Test group: flapless surgery and IL (the same day as placement); (2) control group: flapless implantation and EL (2 mo after placement); (3) no. inserted implants: IL/EL 90/87; (4) prosthesis: maxillary full-arch prostheses; (5) implants: tapered SwissPlus (Zimmer Dental): (6) time of follow-up: 1 y; (7) dropouts: none

Implant failure, prosthesis failure, periimplant marginal bone-level changes, complications, patient satisfaction

Cannizzaro et al,24 2008 (winter)

RCT, parallel design

(1) Total no.: 30 (M/F¼15/15; IL: 29; EL: 31); (2) age range, 18-57 y; (3) diagnosis: maxillary or mandibular partially edentulous arches

(1) Test group: flapless implantation and IL (the same day as placement); (2) control group: flapless implantation and EL (6 wk after placement); (3) no. inserted implants: IL/EL 29/31; (4) prosthesis: metal-ceramic crowns; (5) implants: NanoTIte parallel-walled titanium alloy dental implants with discrete crystalline deposited surface; (6) time of follow-up: 1 y; (7) dropouts: none

Implant failure, prosthesis failure, periimplant marginal bone-level changes, patient satisfaction, complications

Cannizzaro et al,25 2012

RCT, parallel design

(1) Total no.: 30 (M/F¼15/15; IL: 29; EL: 31); (2) age range, 18-57 y; (3) diagnosis: maxillary or mandibular partially edentulous arches

(1) Test group: flapless implantation and IL (the same day as placement); (2) control group: flapless implantation and EL 6 wk (after placement); (3) no. inserted implants: IL/EL 29/31; (4) prosthesis: metal ceramic crowns; (5) implants: NanoTIte parallel-walled titanium alloy dental implants with discrete crystalline deposited surface (Biomet 3i); (6) time of follow-up: 4 y; (7) dropouts: none

Implant failure, prosthesis failure, periimplant marginal bone-level changes, patient satisfaction, complications

Merli et al,23 2008

RCT, parallel design

(1) Total no.: 60 (IL: M/F¼10/20; EL: M/F¼12/18); (2) age range, 19-72 y; (3) diagnosis: partially edentulous arches

(1) Test group: flapless implantation and IL (within 72 h after placement); (2) control group: flapless implantation and EL (after 6 wk of placement); (3) no. inserted implants: IL/EL 35/34; (4) prosthesis: metal ceramic crowns; (5) implants: threaded cylindrical titanium implants with sand-blasted acidetched surface; (6) time of follow-up: 1 y; (7) dropouts: none

Implant failure, prosthesis failure, complications

Merli et al,28 2012

RCT, parallel design

(1) Total no.: 60 (IL: M/F¼10/20; EL: M/F¼12/18); (2) age range, 19-72 y; (3) diagnosis: partially edentulous arches

(1) Test group: flapless implantation and IL (within 72 h after placement); (2) control group: flapless implantation and EL (after 6 wk of placement); (3) no. inserted implants: IL/EL 35/34; (4) prosthesis: metal ceramic crowns; (5) Implants: threaded cylindrical titanium implants with sand-blasted acidetched surface; (6) time of follow-up: 3 y; (7) dropouts: 4 participants with 4 implants (IL 1; EL 3)

Implant failure, prosthesis failure, periimplant marginal bone-level changes, complications

RCT, randomized clinical trial; IL, immediate loading; EL, early loading.

trial used mandibular bar-retained overdentures.29 One trial made use of maxillary complete-arch prostheses.30

The postloading follow-ups were 1 year in 2 trials,29,30 1 year and 4 years in 1 report of 1 trial, and 1 and 3

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years in 2 reports of the remaining study.23-25,28 All of the 6 articles reported implant failures and

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complications.23-25,28-30 Four of the articles published the periimplant marginal bone-level changes.23,25,28,30 Four articles showed participant satisfaction.24,25,29,30 The reviewers’ assessment of the risk of bias in the included studies is presented in Table II; the summarization is shown in Figure 2. Computer software was used to generate a restricted randomization list in 3 trials. The procedures of allocation concealment were described clearly and adequately in those studies.24,25,29,30 Therefore, the risk of selection bias was judged to be low. One trial used a “manually generated randomization list” and was referred to in a 1-year follow-up report23; however, the 3-year followup article for the same study described computerized randomly generated numbers.28 Because a current reviewer had sent an e-mail to the investigator of that study for details without reply, its risk of selection bias was unclear. In all of the included studies, participants and treatment dentists were blinded until

Table II.

implantation ended. At that point, the surgeon needed to know the allocation to decide the loading time of the implants, and the participants knew their study group upon receipt of their allocation.23-25,28-30 When considering the little impact of the blinding method, a low risk of performance bias was indicated. All of the trials mentioned that dentists who had assessed the complications knew of the group allocation, but the dentists in charge of the assessment of other outcomes and the biostatistician were blinded.23-25,28-30 Therefore, the risk of detection bias was considered to be unclear. Five articles reported no loss of participants.23-25,28-30 One article reported 4 participants who failed to return for follow-up, and intention-to-treat analyses and sensitivity per-protocol analyses were performed.28 All 6 articles reported implant failure and some types of complications.23-25,28-30 However, no protocols could be obtained that compared the planned outcome measures with the reported measures. No information about a conflict of

interest was available for any of the articles. According to the trials, the implant failure rate in the IL and EL groups ranged from 0.0% to 3.3%. One trial that used metal-ceramic crowns with a 4-year follow-up showed that IL and EL rates of failure were similar (OR1.0 [95% CI, 0.06-16.76).25 Another trial reported no implant failure with both 1 year and 3 years of follow-up.23,28 In a 1-year follow-up report of a trial that used overdentures, the implant failure rate of IL was not statistically significantly different from EL (OR 0.19 [95% CI, 0.01-4.11]).29 In a trial with fixed full-arch prostheses, the participants in the IL group presented with a lower implant failure rate when compared with the EL group in a 1-year follow-up, without any statistically significant differences (OR 0.31 [95% CI, 0.03-3.08]) (Fig. 3).30 Three trials reported periimplant marginal bone-level changes, with all 3 indicating no statistically significant difference between IL and EL.25,28,30 IL resulted in a loss of more marginal bone than EL in a trial with

Risk of bias

Bias Allocation Concealment (selection bias)

Blinding of Participants and Personnel (performance bias)

Blinding of Outcome Assessment (detection bias)

Incomplete Outcome Data (attrition bias)

Selective Reporting (reporting bias)

Low risk

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Cannizzaro et al,30 2008 (summer)

Low risk

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Cannizzaro et al,24 2008 (winter)

Low risk

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Cannizzaro et al,25 2012 (summer)

Low risk

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Merli et al,23 2008

Unclear

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Merli et al,28 2012

Unclear

Low risk

Low risk

Unclear

Low risk

Unclear

Unclear

Random Sequence Generation (selection bias)

Cannizzaro et al,29 2008 (spring)

Study, y

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Other Bias

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Allocation concealment (selection bias)

Blinding of participants and personnel (performance bias)

Blinding of outcome assessment (detection bias)

Incomplete outcome data (attrition bias)

Cannizzaro G, 2008, Spring

+

+

+

?

+

Cannizzaro G, 2008, Summer

+

+

+

?

+

Cannizzaro G, 2008, Winter

+

+

+

?

+

Cannizzaro G, 2012

+

+

+

?

+

Merli M, 2008

?

+

+

?

+

Merli M, 2012

?

+

+

?

+

-

This present systematic review included 4 trials that fulfilled the inclusion criteria. When considering the great variation in the type of implants and implant-supported prostheses and the various postloading follow-up protocols, neither primary nor secondary outcomes could be performed with a pooled analysis. For the significant clinical heterogeneity, outcomes were assessed with qualitative methods. Because implant failure is a time-sensitive variable, all periods of follow-up were included in this current review to show how the failure rate changed over time. All of the included trials reported a high implant success rate (96.5%-100%) for both IL and EL methods. When considering the current recommendation that insertion torque should be

Other bias

Selective reporting (reporting bias)

DISCUSSION

2 Risk of bias summary: review authors’ judgments about each risk of bias item for each included study.

Study or Subgroup

Issue

reported no intraoperative biologic complications and successful treatments; however, several postoperative complications occurred in both the IL and EL groups, including biologic and prosthetic complications.23-25,28-30 All of the included studies declared that the differences in complications were not statistically significant between the 2 interventions. Table III shows the list of complications.

Participants in the IL group were reported to have significantly more satisfaction than those in the EL group for 2 trials.29,30 In another trial, the investigators revealed a similar trend, but with no statistically significant difference.24,25 All of the 4 trials

Random sequence generation (selection bias)

a 4-year follow-up (MD 0.06 [95% CI, 0.13 to 0.25]) and a trial with a 3-year follow-up (MD 0.06 [95% CI, 0.75 to 0.87]).25,28 However, in a trial with a 1-year follow-up, the trend was the opposite (MD 0.07 [95% CI, 0.14 to 0.00) (Fig. 4).30

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Immediate Loading Early Loading Odds Ratio Events Total Events Total M-H, Fixed [95% Cl]

1.1.1 3-year follow-up (crowns) Merli M, 2012

0

35

0

34

Not estimable

1.1.2 4-year follow-up (crowns) Cannizzaro G, 2012, Summer

1

30

1

30

1.00 [0.06, 16.76]

1.1.3 1-year follow-up (overdentures) Cannizzaro G, 2008, Spring

0

60

2

60

0.19 [0.01, 4.11]

1.1.4 1-year follow-up (fixed full-arch prostheses) Cannizzaro G, 2008, Summer

1

90

3

87

0.31 [0.03, 3.08]

Odds Ratio M-H, Fixed [95% Cl]

0.001 0.1 1 10 1000 Favors experimental Favors control

3 Implant failure rate.

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7 Immediate Loading Early Loading Mean SD Total Mean SD Total

Study or Subgroup

Mean Difference IV, Fixed [95% Cl]

Mean Difference IV, Fixed [95% Cl]

1.2.1 4-year follow-up (crowns) Cannizzaro G, 2012, Summer

0.37 0.35

28

0.31 0.36

28

0.06 [–0.13, 0.25]

1.2.2 1-year follow-up (fixed full-arch prostheses) Cannizzaro G, 2008, Summer

0.55 0.22

90

0.62 0.25

87

–0.07 [–0.14, –0.00]

1.2.3 3-year follow-up (crowns) Merli M, 2012

1.6

30

1.54 1.58

30

0.06 [–0.75, 0.87]

1.63

–0.5 –0.25 0 0.25 0.5 Favors experimental Favors control

4 Periimplant marginal bone-level changes.

Table III.

Types of complications in included studies

Types of Complications Study, y Cannizzaro et al,

29

Immediate Loading Group

2008 (spring)

Periimplantitis; soft-tissue ulcers; clip loss of retention

Cannizzaro et al,30 2008 (summer)

Cannizzaro et al,24 2008 (winter)

Periimplant tissue complications; soft-tissue ulcers; temporomandibular joint, occlusal, mastication problems; fracture or loosening of the provisional prostheses; fracture of the ceramic of definitive prosthesis

Soft-tissue ulcers, clip lost retention Periimplant tissue complications; temporomandibular joint, occlusal, mastication problems; fracture or loosening of the provisional prostheses

Periimplantitis, periimplant tissue complications, fracture of the ceramic of definitive crown

Periimplantitis

Periimplantitis, mucositis

Periimplantitis, mucositis

Loosening of the screw that connects the provisional crown

Fistula, fracture of abutment screw

Cannizzaro et al,25 2012 (summer)a Merli et al,22 2008 Merli et al,28 2012 a

Early Loading Group

No complications occurred from 1- to 3-y follow-up after loading

Between 9 mo and 4 y after loading.

more than 32 Ncm,34 one of the contributing factors may be that the high insertion torques at the time of placement (>40 Ncm in 2 trials, >48 Ncm in the other 2 trials).23-25,28-30 Insertion torque was regarded as an indicator of primary stability.35 More significantly, a high degree of primary stability at implant insertion is considered to be a key prerequisite for obtaining successful osseointegration.36 A systematic review indicated that the quality and quantity of bone plays an important role in primary stability.34 Therefore, another possible reason for the relatively low

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failure rate is that implant sites with adequate bone volume were required by all of the included trials. No included reports demonstrated statistically significant differences for implant failure rates between IL and EL procedures after flapless surgery. Two of the studies indicated slightly higher failure rates in the EL groups.29,30 The original investigators of those studies hypothesized that EL generated unfavorable forces, which disturbed implant healing when bone remodeling decreased the initial high stability of implants.30 However, the number of participants in those

studies was extremely low. In addition, smoking, which is widely considered to have an adverse effect on implant survival,37 was not in the exclusion criteria of all of the included studies. A total of fiveeighths of the participants with failed implants were smokers. Therefore, the current evidence was not sufficient to confirm that the EL procedure is more likely to fail. No apparent differences in periimplant marginal bone changes between the IL and EL groups were observed in the included articles.24,25,28,30 One investigator indicated that the degree of

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Table IV.

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Issue

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Summary of findings

Illustrative Comparative Risks (95% CI)a

Outcomes

Assumed Risk

Corresponding Risk

EL

IL

Quality of the Evidence (GRADE)

Relative Effect, OR (95% CI)

No. Participants (no. studies)

Not estimable

69 (1)

Not estimable

1.00 (0.06-16.76)

60 (1)

4422, lowb,c

0.19 (0.01-4.11)

120 (1)

4442 moderateb,d,e

0.31 (0.03-3.08)

177 (1)

4422, lowb,f,g

Implant failure removal of implants Crowns, follow-up: mean 3 y

High risk population Not estimable

Not estimable

Low risk population Crowns, follow-up: mean 4 y

Study population 33/1000

33/1000 (2-366)

Low risk population 33/1000 Overdentures, follow-up: mean 1 y

33/1000 (2-364)

High risk population 33/1000

7/1000 (0-124)

Low risk population 33/1000 Fixed full-arch, follow-up: mean 1 y

6/1000 (0-123)

High risk population 34/1000

11/1000 (1-99)

Low risk population 34/1000

11/1000 (1-98)

Crowns, follow-up: mean 3 y

0.62 mm

0.07 lower (0.14 lower to 0 higher)

177 (1)

4442, moderateb,g,h

Crowns, follow-up: mean 4 y

0.31 mm

0.06 higher (0.13 lower to 0.25 higher)

56 (1)

4422, lowi

Fixed full-arch prostheses, follow-up: mean 1 y

1.54 mm

0.06 higher (0 to 0.87 higher)

60 (1)

4422, lowj

Periimplant marginal bone-level changes intraoral radiographs

CI, confidence interval; OR, odds ratio; GRADE, Grading of Recommendations, Assessment, Development and Evaluation; EL, early loading; IL, immediate loading; MD, mean difference. 1. Patient or population: patients with flapless-placed dental implants; 2. Settings: Italy; 3. Intervention: immediate loading; 4. Comparison: early loading. a Basis for the assumed risk (such as median control group risk across studies) is provided in footnotes. Corresponding risk (and its 95% CI) is based on assumed risk in comparison with group and relative effect of intervention (and its 95% CI). b Unclear risk of detection bias. c 95% CI is very wide: OR 1.00 (95% CI, 0.06-6.76). d 95% CI is very wide: OR 0.19 (95% CI, I0.01-4.11). e OR 0.19. f 95% CI is very wide: OR 0.31 (95% CI, 0.03-3.08). g OR 0.31. h Unclear risk of selection bias. i 95% CI is very wide: MD 0.06 (0.13 to 0.25). j 95% CI is very wide: MD 0.06 (0.75 to 0.87).

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periimplant bone loss was not affected by the loading differences.24 This was in agreement with the results of other clinical trials.38,39 In conclusion, when taking into account the insufficient number of included trials, this current review does not draw a definitive conclusion as to which method (IL or EL after flapless placement of implants) is more clinically favorable. All of the studies included in this review were performed in Italy. Data from other populations is required to make the results applicable internationally. For all of the included trials, the implant sites were required to provide at least 5.5 mm in bone width to place an implant with a diameter of at least 3.7 mm. As a result, the evidence of this review only applies to selected participants with a sufficient quantity of bone. The variability of prosthesis types and length of follow-up present high clinical diversity; therefore, only 1 trial is included in each subgroup without a pooled analysis. Otherwise, not all of the included trials reported the whole 4 outcomes required by the present review. The insufficient sample size had an effect on reducing the robust nature of the evidence. The methodologic limitations of the 4 trials led to potential detection bias that may affect the assessment of complications. In addition, the imprecision of most results is another reason for downgrading the evidence. However, some results presented a large effect that helped upgrade the quality of the evidence. Therefore, through utilization of the GRADE approach, the evidence regarding implant failure from 1 trial was of moderate quality, with 2 other trials graded as low quality.25,29,30 The quality of evidence regarding periimplant marginal bone-level changes were low in 2 trials,25,30 and moderate in another study (Table IV).28 The purpose of the GRADE approach, when taking into account many factors, is to grade the quality of evidence and strength of recommendations. The system clearly separates evaluations regarding the quality of evidence from the strength of recommendations. The

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9 evidence was downgraded to moderate or even low, mainly because of its risk of bias and imprecision. When considering the variables involved in the decision-making process on therapy, decisions cannot be solely based on the quality of the evidence. Nevertheless, the GRADE concept may be helpful for improving the transparency regarding judgment and explicit acknowledgment of values and preferences that underlie the recommendations. When considering the problem of non-English languages, non-English regional databases were not searched, except for the Chinese electronic databases. In addition, gray literature was unavailable; therefore, selection bias may be considered.

CONCLUSIONS For selected patients with sufficient bone quantity and good bone quality, success is possible with IL or EL procedures after flapless placement of dental implants. There were no differences seen in implant failure rates, periimplant marginal bone-level changes, and complications between the 2 procedures; whereas patients preferred IL. However, because of the small sample size, the currently included evidence was insufficient to fully assess the optimal loading protocol for flapless-placed implants. Consequently, more high-quality evidence is needed to make a definite conclusion. Non-European populations should be included in future comparisons of IL with EL after placing flapless dental implants. Outcomes from trials that used maxillary overdentures, mandibular complete-arch prostheses, and partial fixed dental prostheses are needed. The measurement of patient satisfaction should be consistent and quantifiable. In addition, future trials should involve large sample sizes and long-term follow-up (5 years or longer).

REFERENCES 1. Koller B, Att W, Strub JR. Survival rates of teeth, implants, and double crown-retained removable dental prostheses: a systematic literature review. Int J Prosthodont 2011; 24:109-17.

2. Mamai-Homata E, Margaritis V, KoletsiKounari H, Oulis C, Polychronopoulou A, Topitsoglou V. Tooth loss and oral rehabilitation in Greek middle-aged adults and senior citizens. Int J Prosthodont 2012;25:173-9. 3. Ravindran DM, Sudhakar U, Ramakrishnan T, Ambalavanan N. The efficacy of flapless implant surgery on soft-tissue profile comparing immediate loading implants to delayed loading implants: a comparative clinical study. J Indian Soc Periodontol 2010;14:245-51. 4. Jung RE, Pjetursson BE, Glauser R, Zembic A, Zwahlen M, Lang NP. A systematic review of the 5-year survival and complication rates of implant-supported single crowns. Clin Oral Implants Res 2008;19:119-30. 5. Bidra AS. Consequences of insufficient treatment planning for flapless implant surgery for a mandibular overdenture: a clinical report. J Prosthet Dent 2011;105:286-91. 6. Jeong SM, Choi BH, Kim J, Xuan F, Lee DH, Mo DY, et al. A 1-year prospective clinical study of soft tissue conditions and marginal bone changes around dental implants after flapless implant surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:41-6. 7. Kan JY, Rungcharassaeng K, Ojano M, Goodacre CJ. Flapless anterior implant surgery: a surgical and prosthodontic rational. Pract Periodontics Aesthet Dent 2000;12:467-74. 8. Brodala N. Flapless surgery and its effect on dental implant outcomes. Int J Oral Maxillofac Implants 2009;24:118-25. 9. Turkyilmaz I. Immediate provisional restoration of implant placed using flapless surgery and ridge mapping. N Y State Dent J 2011;77:21-3. 10. Becker W, Goldstein M, Becker BE, Sennerby L. Minimally invasive flapless implant surgery: a prospective multicenter study. Clin Implant Dent Relat Res 2005;7:S21-7. 11. Sclar AG. Guidelines for flapless surgery. J Oral Maxillofac Surg 2007;65:20-32. 12. Fortin T, Bosson JL, Isidori M, Blanchet E. Effect of flapless surgery on pain experienced in implant placement using an image-guided system. Int J Oral Maxillofac Implants 2006;21:298-304. 13. Komiyama A, Klinge B, Hultin M. Treatment outcome of immediately loaded implants installed in edentulous jaws following computer-assisted virtual treatment planning and flapless surgery. Clin Oral Implants Res 2008;19:677-85. 14. Berdougo M, Fortin T, Blanchet E, Isidori M, Bosson JL. Flapless implant surgery using an image-guided system. A 1- to 4-year retrospective multicenter comparative clinical study. Clin Implant Dent Relat Res 2010; 12:142-52. 15. Brånemark PI, Engstrand P, Ohrnell LO, Gröndahl K, Nilsson P, Hagberg K, et al. Brånemark Novum: a new treatment concept for rehabilitation of the edentulous mandible. Preliminary results from a prospective clinical follow-up study. Clin Implant Dent Relat Res 1999;1:2-16.

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Volume 16. Ozan O, Turkyilmaz I, Yilmaz B. A preliminary report of patients treated with early loaded implants using computerized tomographyguided surgical stents: flapless versus conventional flapped surgery. J Oral Rehabil 2007;34:835-40. 17. Esposito M, Grusovin MG, Achille H, Coulthard P, Worthington HV. Interventions for replacing missing teeth: different times for loading dental implants. Cochrane Database Syst Rev 2009;21:CD003878. 18. De Bruyn H, Raes F, Cooper LF, Reside G, Garriga JS, Tarrida LG, et al. Three-years clinical outcome of immediate provisionalization of single Osseospeed() implants in extraction sockets and healed ridges. Clin Oral Implants Res 2013;24:217-23. 19. Margossian P, Mariani P, Stephan G, Margerit J, Jorgensen C. Immediate loading of mandibular dental implants in partially edentulous patients: a prospective randomized comparative study. Int J Periodontics Restorative Dent 2012;32:e51-8. 20. Cochran DL, Jackson JM, Bernard JP, ten Bruggenkate CM, Buser D, Taylor TD, et al. A 5-year prospective multicenter study of early loaded titanium implants with a sandblasted and acid-etched surface. Int J Oral Maxillofac Implants 2011;26:1324-32. 21. Testori T, Galli F, Capelli M, Zuffetti F, Esposito M. Immediate nonocclusal versus early loading of dental implants in partially edentulous patients: 1-year results from a multicenter, randomized controlled clinical trial. Int J Oral Maxillofac Implants 2007;22: 815-22. 22. Merli M, Bernardelli F, Esposito M. Immediate versus early nonocclusal loading of dental implants placed with a flapless procedure in partially edentulous patients: preliminary results from a randomized controlled clinical trial. Int J Periodontics Restorative Dent 2008;28:453-9. 23. Merli M, Merli A, Bernardelli F, Lombardini F, Esposito M. Immediate versus early nonocclusal loading of dental implants placed flapless in partially edentulous patients. One-year results from a randomised controlled trial. Eur J Oral Implantol 2008; 1:207-20. 24. Cannizzaro G, Leone M, Torchio C, Viola P, Esposito M. Immediate versus early loading of 7-mm-long flapless-placed single implants: a split-mouth randomised controlled clinical trial. Eur J Oral Implantol 2008;1:277-92.

25. Cannizzaro G, Leone P, Leone M, Ferri V, Viola P, Esposito M. Immediate versus early loading of 6.5-mm-long flapless-placed single implants: a 4-year after loading report of a split-mouth randomized controlled trial. Eur J Oral Implantol 2012; 5:111-21. 26. Van de Velde T, Sennerby L, De Bruyn H. The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation: a randomized clinical trial. Clin Oral Implants Res 2010;21:1223-33. 27. Cannizzaro G, Felice P, Leone M, Checchi V, Esposito M. Flapless versus open flap implant surgery in partially edentulous patients subjected to immediate loading: 1-year results from a split-mouth randomised controlled trial. Eur J Oral Implantol 2011;4:177-88. 28. Merli M, Moscatelli M, Mariotti G, Piemontese M, Nieri M. Immediate versus early non-occlusal loading of dental implants placed flapless in partially edentulous patients: a 3-year randomized clinical trial. J Clin Periodontol 2012;39:196-202. 29. Cannizzaro G, Leone M, Esposito M. Immediate versus early loading of two implants placed with a flapless technique supporting mandibular bar-retained overdentures: a single-blinded, randomised controlled clinical trial. Eur J Oral Implantol 2008;1:33-43. 30. Cannizzaro G, Torchio C, Leone M, Esposito M. Immediate versus early loading of flapless-placed implants supporting maxillary full-arch prostheses: a randomised controlled clinical trial. Eur J Oral Implantol 2008;1:127-39. 31. Moon SY, Kim SG, Lim SC, Ong JL. Histologic and histomorphometric evaluation of early and immediately loaded implants in the dog mandible. J Biomed Mater Res 2008; 86:1122-7. 32. Alsabeeha N, Atieh M, Payne AG. Loading protocols for mandibular implant overdentures: a systematic review with metaanalysis. Clin Implant Dent Relat Res 2010;12(suppl 1):e28-38. 33. Esposito M, Maghaireh H, Grusovin MG, Ziounas I, Worthington HV. Soft tissue management for dental implants: what are the most effective techniques? A Cochrane systematic review. Eur J Oral Implantol 2012;5:221-38.

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34. Chung S, McCullagh A, Irinakis T. Immediate loading in the maxillary arch: evidence-based guidelines to improve success rates: a review. J Oral Implantol 2011;37:610-21. 35. Wang HL, Boyapati L. “PASS” principles for predictable bone regeneration. Implant Dent 2006;15:8-17. 36. Robling AG, Turner CH. Mechanical signaling for bone modeling and remodeling. Crit Rev Eukaryot Gene Expr 2009;19: 319-38. 37. Shibli JA, Piattelli A, Iezzi G, Cardoso LA, Onuma T, de Carvalho PS, et al. Effect of smoking on early bone healing around oxidized surfaces: a prospective, controlled study in human jaws. J Periodontol 2010; 81:575-83. 38. Capelli M, Esposito M, Zuffetti F, Galli F, Del Fabbro M, Testroi TA. 5-year report from a multicentre randomised clinical trial: immediate non-occlusal versus early loading of dental implants in partially edentulous patients. Eur J Oral Implantol 2010;3: 209-19. 39. Zembic A, Glauser R, Khraisat A, Hämmerle CH. Immediate vs. early loading of dental implants: 3-year results of a randomized controlled clinical trial. Clin Oral Implants Res 2010;21:481-9.

Corresponding author: Dr Ke Zhao Department of Prosthodontics Guanghua School of Stomatology Hospital of Stomatology Sun Yat-sen University No. 56 Lingyuan West Rd 510055 Guangzhou CHINA E-mail: [email protected] Acknowledgments The authors thank Dr Taixiang Wu and Dr Guanjian Liu (Evidence-Based Medicine and Clinical Epidemiology Centre, West China Hospital, Sichuan University, Chengdu, China) for their help and advice on writing a systematic review and dealing with data; and Dr Ronald E. Jung (Department of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland) for his excellent advice on this article. Copyright ª 2014 by the Editorial Council for The Journal of Prosthetic Dentistry.

Xu et al

Immediate versus early loading of flapless placed dental implants: a systematic review.

The flapless implant technique is a predictable procedure with several advantages and a high overall implant survival rate. Immediate loading and earl...
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