Immediate Versus Early Loading of Mini-Implants Supporting Mandibular Overdentures: A Preliminary 3-Year Clinical Outcome Report Waleed Hamed Maryod, BDS, MSc, PhDa/Samer Mostafa Ali, BDS, MSc, PhDa/ Ahmad Fathalla Shawky, BDS, MSc, PhDb

Purpose: The aim of this preliminary clinical report was to evaluate and compare the clinical outcomes of immediate and early loaded mini-implants (MIs) supporting mandibular overdentures. Materials and Methods: Thirty-six completely edentulous patients (20 men and 16 women) complaining of insufficient retention of their mandibular dentures were randomly assigned to two groups. Each patient received four MIs in the interforaminal area of the mandible using the nonsubmerged flapless surgical approach. In group 1 (G1), MIs were loaded with mandibular overdentures using the immediate loading protocol, while in group 2 (G2), MIs were loaded with overdentures using the early loading protocol. The cumulative survival rate was calculated using Kaplan-Meier analysis. Peri-implant health indices (Plaque Index/Bleeding Index), probing depths, and marginal bone levels were recorded for both groups after MI insertions and 6, 12, 24, and 36 months thereafter. Results: The cumulative implant survival rates were 91.7% and 96.7% for G1 and G2, respectively. G1 recorded significantly higher Plaque Index, Bleeding Index, and probing depths than G2 after 12 months, while other observation times demonstrated no significant difference between groups. Most of the recorded marginal bone loss occurred in the first year, and no significant bone loss was noted in subsequent years. After 6 months, marginal bone loss was significantly higher in G1 compared to G2, but no significant differences between groups were noted thereafter. Conclusions: Within the limitations of this study’s research design and duration of follow-up outcome analyses, immediate and early loading protocols showed good clinical results with favorable peri-implant tissue response 3 years after implant insertion. Early loading of MIs supporting a mandibular overdenture appears to be preferable to immediate loading. Int J Prosthodont 2014;27:553–560. doi: 10.11607/ijp.3845

I

mplant-retained overdentures may be regarded as predictable and effective in the management of edentulous patients.1 While mini-implants (MIs; solid one-piece implants with a diameter ranging from 1.8 to 2.4 mm inserted by single-stage flapless procedure) were initially used for temporary stabilization of

aLecturer

of Removable Prosthodontics, Modern Science and Arts University, Cairo, Egypt. bLecturer of Removable Prosthodontics, Faculty of Dentistry, 6 October University, Cairo, Egypt. Correspondence to: Waleed Hamed Ahmed Maryod, Department of Removable Prosthodontics, Faculty of Dentistry, Modern Science and Arts University, PO Box 12585, 26 July Mehwar Road, intersection with Wahat Road, 6 October City, Egypt. Fax: +202 38371543. Email: [email protected] ©2014 by Quintessence Publishing Co Inc.

provisional prostheses,2–4 they are now also employed as an alternative to conventional implants for definitive rehabilitation of edentulous patients.2,4–10 MIs are popularly regarded as a preferred treatment option whenever mandibular alveolar ridge morphology precludes use of conventional implants, especially in older and systemically compromised patients,4,9,11,12 given an attendant less complicated surgical procedure, reduced treatment time, and possibly cost.2,6 However, osseointegrated MIs are subjected to greater microstrains than conventional ones due to the smaller surface area contacting the surrounding bone.13 These implants also are problematic in the context of their different mechanical properties, such as deformation and fracture.14,15 Published reports suggest an MI-retained overdenture survival rate of 81% to 97.4%.2,5,6,8,9 Immediate implant loading may result in interfacial micromotion and compromise the healing process.16

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Immediate Versus Early Loading of Mini-Implants Supporting Mandibular Overdentures

Table 1   B  aseline Characteristics of Patients in Both Groups at the Onset of the Trial Immediate loading Early loading group (n = 16) group (n = 16)

Characteristic Mean age (y)

63.4

Sex (male/female)

64.8

10/8

10/8

Mean period of mandibular edentulism (y)

9.2

10.5

Mean number of previously made mandibular dentures

1.8

1.9

24.3

22.8

Mean mandibular bone height in the symphysis (mm)

Fig 1   MIs inserted using the single-stage flapless surgical approach.

Fig 2   The fitting surface of the mandibular overdenture in G1.

Fig 3   The fitting surface of the mandibular overdenture in G2.

If micromotion is relatively small and does not exceed 100 µm, bone formation may still take place. However, if the micromotion is in excess of 100 µm, a seriously compromised fibrous tissue interface will develop and prevent the desired interfacial osteogenesis.17,18 It is, therefore, reasonable to regard loading protocols as more critical when MIs are used to support overdentures, although only a few attempts at scrupulously documented longitudinal outcomes of MI use have been published.9 The aim of this preliminary clinical report was to evaluate and compare the clinical outcomes of immediate and early loaded MIs supporting a mandibular overdenture. The null hypothesis was that no significant difference between the two loading protocols would be observed.

denture-wearing experiences were selected from the outpatient clinic of the Prosthodontic Department, Faculty of Dentistry, Modern Science and Arts University, Cairo, Egypt. Based on the results of a previous randomized trial carried out to compare the clinical outcome of two loading protocols for implant-retained mandibular overdentures,19 it was estimated that a sample size of 18 patients per group was necessary to provide 80% power with a type I error of 0.05. The study was conducted according to principles stated in the Helsinki Declaration, and the Faculty’s Clinical Research Ethics Committee approved the research protocol. Patients were included in the study provided that they fulfilled the following criteria: healthy mucosa, sufficient interarch space, little or nonresorbed mandibles (shape A or B according to the classification of the residual edentulous ridge proposed by Lekholm and Zarb),20 and a minimum width of 5 mm measured by a caliper. Patients were excluded if they had one or more of the following conditions: diabetes, a smoking habit, osteoporosis, immune deficiency, radiotherapy to the head and neck region, and/or anticoagulant

Materials and Methods Study Population Thirty-six completely edentulous patients (20 men and 16 women) with maladaptive mandibular

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Maryod et al

therapy. Detailed written information about the surgical and prosthetic procedures was provided to all participants prior to obtaining their written consent. Random allocation of patients was executed by means of a computerized balanced randomization method21 to ensure pretreatment comparability of the groups with respect to age, sex, edentulous period in the mandible, number of previously made mandibular dentures, and mandibular bone height at symphysis (measured in preoperative panoramic radiograph). The patients were then randomly distributed into two equal groups: group 1 (G1), in which MIs were loaded with mandibular overdentures on the same day of implant placement using the immediate loading protocol; and group 2 (G2), in which MIs were loaded with overdentures using the early loading protocol. Baseline characteristics of the two groups are listed in Table 1. Surgical and Prosthetic Procedures At the onset of the study, all patients received new maxillary and mandibular complete dentures constructed with bilateral balanced occlusion using Vivodent (Ivoclar Vivadent) acrylic resin teeth. All patients were asked to wear their dentures for 2 months before implant surgery to enhance neuromuscular adaptation. A preoperative panoramic radiograph was performed for each patient to mark implant placement sites. Each patient received four 1.8 × 15 mm O-ring mini-dental implants (MDI, 3M ESPE) in the interforaminal mandibular region using the single-stage flapless surgical approach (Fig 1). The implants were inserted by the same oral surgeon, who was blinded to the treatment groups according to the procedures described by Ahn et al2 and Shatkin et al.8 The fitting surface of the mandibular denture was marked at proposed implant sites with an indelible pencil and placed in the patient’s mouth after drying the mucosa to transfer the marks to the alveolar ridge. A 1.1-mmdiameter pilot drill was used only to perforate the cortical plate (no longer than half the threaded length of the implant) in order to provide good primary implant stability. Due to their self-tapping capacity, further implant insertion was performed using a finger driver followed by a winged thumb wrench and adjustable torque wrench. Immediate loading group. The overdenture attachment system consisted of metal housings with O-rings (3M ESPE). Recesses were prepared in the fitting surface of the mandibular denture for the metal housings. The housings were then picked up to the fitting surface of the mandibular denture using self-curing acrylic resin while the patient held the

dentures in centric occlusion (Fig 2). Excess acrylic resin was trimmed, the occlusion was refined, and the denture was placed in immediate functional loading on the same day of implant placement. Early loading group. Using pressure-indicating paste (FIT CHECKER, GC America), a generous relief was provided on the undersurface of the mandibular overdenture around each MI (a relief space of at least 5 mm around and 1 mm above MI abutments) to avoid any torquing forces or initial loading. The patients were dismissed with their relieved dentures in place and were instructed not to eat without the dentures in place. After 2 weeks, the relieved regions of the denture were relined with autopolymerized addition silicone resilient liner (Softliner, Promedica) using a closed-mouth technique (Fig 3). The patients continued to wear the dentures for 3 months, then the soft liner was removed and the definitive attachments (metal housings with O-rings) were picked up to the fitting surface of the mandibular denture using selfcuring acrylic resin. All prosthetic procedures were made by the same prosthodontist (MWH). For both groups, a soft diet and cold compresses were recommended for 7 days after implant insertion. Patients received postoperative instructions about oral hygienic protocol, which included the use of mouth rinse and brushing of the MIs abutments with a soft brush. They were recalled every 3 months throughout the study period for overdenture maintenance. Evaluation of Peri-implant Health Although it is conceded that clinical evaluation of peri-implant tissues does not necessarily have a bearing on marginal bone behavior, it was nonetheless recorded after implant insertion (T0) and 6 (T6), 12 (T12), 24 (T24), and 36 (T36) months thereafter. The following parameters were evaluated: Modified Plaque Index (MPI). The presence of plaque was assessed according to the MPI,22 with ranking from 0 to 3: 0 = no plaque detected, 1 = plaque only recognized by running a probe across the surface supragingivally, 2 = plaque can be seen with unaided vision, 3 = abundance of soft matter. Modified Bleeding Index (MBI). Bleeding on probing was determined according to the modification of Mombelli et al22 from the original technique of Loe and Silness23 with ranking from 0 to 3: 0 = no bleeding, 1 = pinpoint bleeding, 2 = linear bleeding, 3 = profuse bleeding. Probing depth (PD). The distance between the marginal border of the gingiva around MIs and the tip of the periodontal probe (Vivacare TPS, Vivadent) when placed in peri-implant gingival pocket was measured in millimeters and considered as pocket depth.

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Immediate Versus Early Loading of Mini-Implants Supporting Mandibular Overdentures

Fig 4  Traced periapical radiograph.

Statistical Analysis Data were analyzed with SPSS version 18 (SPSS). The data were nonparametric as verified by the onesample Kolmogorov-Smirnov Test. Graphical presentations of MPI, MBI, and PD were made using bar charts, whereas MBL was presented using a box plot. The Friedman test was used to compare different observation times within groups, and Wilcoxon signed rank test was used to compare between each two times. For between-group comparisons, the nonparametric Mann-Whitney test was used. A comparison of the survival rates between the two groups was done by applying the log-rank test. The threshold for statistical significance was set at P < .05.

MPI, MBI, and PD were measured at the labial, distal, lingual, and mesial surfaces of each implant abutment by one calibrated examiner (ASM). Marginal bone loss (MBL). Marginal bone change was measured using sequential periapical radiographs and the long-cone paralleling technique with a commercial Rinn XCP film holder (XCP bite blocks, Dentsply). A polyvinyl siloxane (Exabite II, GC America) occlusal jig was used to standardize the angulation and position of the film to the x-ray beam and to ensure a reproducible radiographic analysis. The periapical films were scanned using a black-andwhite translucent scanner. Evaluation of the marginal bone level around the implants was performed using image analysis software (Autocad 2006, version Z 54.10, Autodesk) to compensate for radiographic distortion.24 The squared abutment base was used as the reference point (point A; Fig 4). Using the measuring tool of the software, the distance between the reference point and the implant-bone contact point was measured to indicate the marginal bone level. MBL was calculated by subtracting corresponding bone levels at T6, T12, T24, and T36 from bone levels at T0. Measurements were made on both mesial and distal aspects of each implant by one calibrated examiner (SAF), and the mean was subjected to statistical analysis. Implant survival. To estimate the cumulative survival rate, a Kaplan-Meier analysis was made according to the success criteria of Smith and Zarb.25 The implants were considered a failure if significant MBL, peri-implant radiolucency, mobility, infection, pain, discomfort, and/or neurosensory alteration were present. An implant was classified as a “survived implant” when it was still functioning and did not need immediate removal but did not fulfill the success criteria.

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Results Thirty of the original 36 participants attended their 3-year follow-up monitoring appointments. Two patients in G1 died and another patient moved out of the area. Three patients in G2 were lost to follow-up due to severe medical reasons. A total of 60 MIs in each group (15 participants/group) were therefore available for the 3-year follow-up examination. In G1, 3 MIs (2 MIs in 1 patient and 1 MI in another patient) were lost after 6 months. Two additional implants were removed after 12 months, and no further failures occurred thereafter. Therefore, the cumulative survival rate in this group was 91.7%. In G2, only 2 implants failed after 1 year, yielding a 96.7% cumulative survival rate in this group. The overall survival rate of MIs (in both groups together) was 94.2%. The average failure rate was 8.3% and 3.3% for G1 and G2, respectively. Kaplan-Meier analysis of the cumulative survival rate of MIs is presented in Fig 5. The survival rate of MIs in G2 was significantly higher than in G1 (log-rank test, P = .009). Implant failures were associated with pain and mobility, with or without suppuration. The failed implants were removed, and the remaining implants were left to retain the mandibular overdentures. Although the correlative significance of MPI scores, MBI scores, PDs, and MBL have not been compellingly shown to influence treatment outcomes of implant therapy, they were nonetheless employed for both groups. The recorded values are presented in Figs 6 to 9. MPI, MBI, and MBL increased with the advance of time in G1 (Friedman test, P = .00, .001, and .00) and in G2 (P = .00, .00, and .002), respectively. PD increased significantly at T12 then decreased thereafter (P = .001 for G1 and .002 for G2). Pairwise comparisons between observation times (Wilcoxon signed rank test) for all tested parameters in both groups are presented in Table 2.

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Maryod et al

2.5

40

0.5

Early loading censored

50 0

3

6

12

24

1.0

0

36

T0

T6

T12

Time (mo)

.002*

T24

T36

Observation

Fig 5  Kaplan-Meier analysis of the cumulative survival rate. The MI survival rates were 91.7% and 96.7% for G1 and G2, respectively.

3.0

1.688 1.75

Immediate loading censored

Early loading (G2) 1.80 1.647

60

Immediate loading (G1)

1.5

1.588

Early loading

.89

0.80

70

.52

Group

1.438 0.50

80

.02*

2.0

Group Immediate loading

.004*

0.00 0.00

90

Mean MPI

Cumulative survival rate (%)

100

.012*

.056

Fig 6  Comparison of Modified Plaque Index (MPI) between groups at different observation times.

2.0

.66

.66

.001*

.005*

.197

.013*

Group

Group

T24

T36

Observation

Observation

Fig 8   Comparison of probing depth (PD) between groups at different observation times.

1.0 0.5 0

1.06 ± .49

.49 1.17 ± .65

1.5

.23 1.12 ± .51

2.0

.68 1.29 ± .63

.011*

.73 ± .45

Mean MBL (mm)

2.5

1.03 ± .61

Fig 9  Comparison of marginal bone loss (MBL) between groups at different observation times.

Group Immediate loading (G1) Early loading (G2)

.37 ± .18

Fig 7   Comparison of Modified Bleeding Index (MBI) between groups at different observation times.

T12

0.844

T6

1.203

1.456

T0

0.967 0.75

0

.93 ± .52

T36

0.766 0.375

T24

0.578 0.641

T12

1.0

0.85

1.933

1.333

T6

Early loading (G2)

0.5 1.313 1.125

T0

0.40

0

1.125

1.0

1.235

1.941

Early loading (G2)

Immediate loading (G1)

1.5 Mean PD

2.0

0.00 0.00

Mean MBI

Immediate loading (G1)

T6

T12

T24

T36

Observation

G1 recorded significantly higher MPI, MBI, and PD than G2 at T6 and T12 (Mann-Whitney test), whereas other observation times demonstrated no significant difference between groups (Fig 6 to 8). At T6, MBL of G1 was significantly higher than values of G2, and no significant differences between groups were noted thereafter (Fig 9).

Discussion The MIs used in the present study are supplied with O-ring attachments and are designed for immediate loading of overdentures. The authors used resilient liners to retain overdentures and load the implants early (after 2 weeks), then the O-ring attachments

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Immediate Versus Early Loading of Mini-Implants Supporting Mandibular Overdentures

Table 2   M  ultiple (Pairwise) Comparisons Between Different Observation Times for All Tested Parameters in Both Groups* T0–T6

T0–T12

T0–T24

T0–T36

T6–T12

T6–T24

T6–T36

T12–T24

T12–T36

T24–T36

MPI G1

.001

.001

.00

.001

.046

.013

.036

.36

.79

.72

G2

.011

.002

.001

.001

.21

.004

.003

.10

.16

.56

G1

.00

.00

.001

.003

.008

.015

.046

.86

.09

.10

G2

.014

.00

.004

.004

.001

.015

.039

.64

.50

.77

MBI

PD G1

.046

.001

.003

.001

.004

.013

.003

.061

.22

.15

G2

.009

.065

.27

.14

.002

.004

.002

.26

.68

.43

G1









.013

.019

.036

.054

.34

.35

G2









.002

.001

.001

.063

.28

.57

MBL

G1 = immediate loading group; G2 = early loading group; T0, T6, T12, T24, T36 are at implant insertion and 6, 12, 24, and 36 months after insertion; MPI = Modified Plaque Index; MBI = Modified Bleeding Index; PD = probing depth; MBL = marginal bone loss. *Number in each cell indicates P value of Wilcoxon signed rank test.

were incorporated in the denture base 3 months later. Another MI system (Dentatus AtlantisR, Dentatus) uses a resilient silicone material inside the denture base to provide proper retention without the need of O-ring attachments. This system is cost-effective and may also be considered for early loading of MIs. Four maximum-length (15 mm) MIs were inserted to support mandibular overdentures as per recommendations employed in other studies.6,8,9 Despite the reduced MI diameter and surface area, the overall survival rate of MIs (94.2%) was accepted and compared to other studies conducted on MIs.4,5,8 This may be attributed to favorable mandibular morphology in the interforaminal area and consequent attainment of good primary stability. In this study, the periotest was employed to record this perception during implant placement. High long-term survival rates for osseointegrated implants in the anterior mandible have been reported in the literature.26–28 The MI cumulative survival rates were 91.7% and 96.7% for G1 and G2, respectively. The cumulative survival rate of G1 was consistent with the results reported by Bulard and Vance.5 However, the survival rate was lower than the rate reported by Elsyad et al9 after a similar observation period (96.4%). In the present study, the implants were evenly distributed in the interforaminal area, while in the study by Elsyad et al, the implants were positioned more posteriorly in the canine and first premolar area. It is possible that the higher success rate with a more posterior implant arrangement could be explained by a force distribution that would be more favorable with less bending moments since the implants could act as a fulcrum during loading.29

558

The survival rate of MIs in G2 was significantly higher than in G1 and can be compared to the survival rate of immediately loaded conventional diameter implants supporting a mandibular overdenture in other studies.30,31 The high survival rate in G2 may be due to the implants being left unloaded for 2 weeks, then early loaded with resilient liners. These liners absorb energy and distribute masticatory forces to the implants and edentulous ridge.32,33 The presumed shock-absorbing ability of a soft liner reduces implant micromotion during the initial healing period. This contrasts with the Tawse-Smith et al report34 wherein premature overloading and early implant failure were employed for conventional diameter implants, although generous relief of the overdenture base was provided around the healing abutments and a tissue conditioner was applied to control adverse torqueing forces. Although oral hygiene instructions were given to all patients, their cooperation was uneven. This might have led to a time-dependent increase in plaque accumulation. PD showed a significant increase after 1 year (G1 = 1.45 mm, G2 = 0.85 mm) followed by a subsequent decrease. The increased PD could be attributed to the increased MBL (as confirmed by the results of this study) and the gingival proliferation around MI abutments. The gingival shrinkage, which occurred as a result of overdenture settling,34,35 may be the cause of PD reduction after the first year. The majority of MBL around MIs occurred in the first year after loading, and no significant bone loss occurred in subsequent years. In G1, MBL after 3 years was 1.17 mm. A similar level of bone loss (1.2 mm) was reported in the study of Elsyad and colleagues.9 The

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Maryod et al

bone resorption associated with MIs in G1 was comparable to that experienced with small36 and wide37 diameter implants and ranged from 0.7 to 1.03 mm in the first year. The mean MBL observed for both groups at 1 and 3 years remained in the normal range of values reported in the literature (< 1 mm in the first year and < 0.2 mm annually thereafter).38,39 The lower level of MBL could be attributed to the flapless placement of MIs, which causes minimal disruption to the vascularity of periosteum and preserves the bone height around the implants after surgery.2,5,40 During the first year after implant insertion, G2 recorded significantly lower MPI, MBI, PD, and MBL than G1. These findings could be attributed to the resilient liner used in G2 before the final attachments (O-rings) were placed. Elsyad and Shoukouki41 speculated that resilient liners decrease MPI scores, gingival scores, PDs, and MBL over time when used as attachments for implant-retained mandibular overdentures. Overall, the null hypothesis was not rejected. It must be conceded that having a single prosthodontist fabricating all of the prostheses seriously limits this report’s external validity. An additional limitation is the use of a single dependent investigator to assess the employed outcome measures given the inherent risk of bias. Future studies should recognize this one’s limitations to ensure a more rigorous research design.

Conclusions Within the limitations of this study, the following conclusions are suggested: MIs in edentulous mandibles using the one-stage flapless operative technique and loaded with overdentures via either immediate or early loading protocols showed favorable clinical outcomes after 3 years of clinical observation. Early loading of MIs appears to be preferable to immediate loading as evaluated by the employed parameters and as defined by the duration of the observation period.

Acknowledgments The authors reported no conflicts of interest related to this study.

References   1. Attard NJ, Zarb GA. Immediate and early implant loading protocols: A literature review of clinical studies. J Prosthet Dent 2005; 94:242–258.   2. Ahn MR, An KM, Choi JH, Sohn DS. Immediate loading with mini dental implants in the fully edentulous mandible. Implant Dent 2004;13:367–372.

  3. el Attar MS, el Shazly D, Osman S, el Domiati S, Salloum MG. Study of the effect of using mini-transitional implants as temporary abutments in implant overdenture cases. Implant Dent 1999; 8:152–158.   4. Scepanovic M, Calvo-Guirado JL, Markovic A, et al. A 1-year prospective cohort study on mandibular overdentures retained by mini dental implants. Eur J Oral Implantol 2012;5:367–379.  5. Bulard RA, Vance JB. Multi-clinic evaluation using minidental implants for long-term denture stabilization: A preliminary biometric evaluation. Compend Contin Educ Dent 2005; 26:892–897.   6. Griffitts TM, Collins CP, Collins PC. Mini dental implants: An adjunct for retention, stability, and comfort for the edentulous patient. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 100:e81–e84.   7. Jofre J, Hamada T, Nishimura M, Klattenhoff C. The effect of maximum bite force on marginal bone loss of mini-implants supporting a mandibular overdenture: A randomized controlled trial. Clin Oral Implants Res 2010;21:243–249.  8. Shatkin TE, Shatkin S, Oppenheimer BD, Oppenheimer AJ. Mini dental implants for long-term fixed and removable prosthetics: A retrospective analysis of 2514 implants placed over a five-year period. Compend Contin Educ Dent 2007;28:92–99; quiz 100–101.  9. Elsyad MA, Gebreel AA, Fouad MM, Elshoukouki AH. The clinical and radiographic outcome of immediately loaded mini implants supporting a mandibular overdenture. A 3-year prospective study. J Oral Rehabil 2011;38:827–834. 10. Elsyad MA, Ghoneem NE, El-Sharkawy H. Marginal bone loss around unsplinted mini-implants supporting maxillary overdentures: A preliminary comparative study between partial and full palatal coverage. Quintessence Int 2013;44:45–52. 11. Balkin BE, Steflik DE, Naval F. Mini-dental implant insertion with the auto-advance technique for ongoing applications. J Oral Implantol 2001;27:32–37. 12. Preoteasa E, Melescanu-Imre M, Preoteasa CT, Marin M, Lerner H. Aspects of oral morphology as decision factors in mini-implant supported overdenture. Rom J Morphol Embryol 2010;51:309–314. 13. Sallam H, Kheiralla LS, Aldawakly A. Microstrains around standard and mini implants supporting different bridge designs. J Oral Implantol 2012;38:221–229. 14. Kanie T, Nagata M, Ban S. Comparison of the mechanical properties of 2 prosthetic mini-implants. Implant Dent 2004;13:251–256. 15. Simon H, Caputo AA. Removal torque of immediately loaded transitional endosseous implants in human subjects. Int J Oral Maxillofac Implants 2002;17:839–845. 16. Romanos GE, Nentwig GH. Immediate versus delayed functional loading of implants in the posterior mandible: A 2-year prospective clinical study of 12 consecutive cases. Int J Periodontics Restorative Dent 2006;26:459–469. 17. Hansson HA, Albrektsson T, Branemark PI. Structural aspects of the interface between tissue and titanium implants. J Prosthet Dent 1983;50:108–113. 18. Szmukler-Moncler S, Salama H, Reingewirtz Y, Dubruille JH. Timing of loading and effect of micromotion on bone-dental implant interface: Review of experimental literature. J Biomed Mater Res 1998;43:192–203. 19. Elsyad MA, Al-Mahdy YF, Fouad MM. Marginal bone loss adjacent to conventional and immediate loaded two implants supporting a ball-retained mandibular overdenture: A 3-year randomized clinical trial. Clin Oral Implants Res 2012;23: 496–503.

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Immediate Versus Early Loading of Mini-Implants Supporting Mandibular Overdentures

20. Lekholm U, Zarb GA. Patient selection and preparation. In: Brånemark P-I, Zarb GA, Albrektsson T, eds. Tissue-Integrated Prostheses: Osseointegration in Clinical Dentistry. Chicago; Quintessence, 1985:199–210. 21. Zielhuis GA, Straatman H, van ‘t Hof-Grootenboer AE, van Lier HJ, Rach GH, van den Broek P. The choice of a balanced allocation method for a clinical trial in otitis media with effusion. Stat Med 1990;9:237–246. 22. Mombelli A, van Oosten MA, Schurch E Jr, Land NP. The microbiota associated with successful or failing osseointegrated titanium implants. Oral Microbiol Immunol 1987;2:145–151. 23. Loe H, Silness J. Periodontal disease in pregnancy. I. Prevalence and severity. Acta Odontol Scand 1963;21:533–551. 24. Canullo L, Fedele GR, Iannello G, Jepsen S. Platform switching and marginal bone-level alterations: The results of a randomized-controlled trial. Clin Oral Implants Res 2010;21:115–121. 25. Smith DE, Zarb GA. Criteria for success of osseointegrated endosseous implants. J Prosthet Dent 1989;62:567–572. 26. Adell R, Lekholm U, Rockler B, Brånemark PI. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg 1981;10:387–416. 27. Adell R, Eriksson B, Lekholm U, Brånemark PI, Jemt T. Long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants 1990; 5:347–359. 28. Naert I, De Clercq M, Theuniers G, Schepers E. Overdentures supported by osseointegrated fixtures for the edentulous mandible: A 2.5-year report. Int J Oral Maxillofac Implants 1988;3: 191–196. 29. Elsyad MA, Elsaadawy MG, Abdou AM, Habib AA. Effect of different implant positions on strain developed around four implants supporting a mandibular overdenture with rigid telescopic copings. Quintessence Int 2013;44:679–686. 30. Chiapasco M, Abati S, Romeo E, Vogel G. Implant-retained mandibular overdentures with Brånemark System MKII implants: A prospective comparative study between delayed and immediate loading. Int J Oral Maxillofac Implants 2001;16:537–546. 31. Gatti C, Haefliger W, Chiapasco M. Implant-retained mandibular overdentures with immediate loading: A prospective study of ITI implants. Int J Oral Maxillofac Implants 2000;15:383–388.

32. Adrian ED, Krantz WA, Ivanhoe JR. The use of processed silicone to retain the implant-supported tissue-borne overdenture. J Prosthet Dent 1992;67:219–222. 33. Kiat-Amnuay S, Khan Z, Gettleman L. Overdenture retention of four resilient liners over an implant bar. J Prosthet Dent 1999; 81:568–573. 34. Tawse-Smith A, Perio C, Payne AG, Kumara R, Thomson WM. One-stage operative procedure using two different implant systems: A prospective study on implant overdentures in the edentulous mandible. Clin Implant Dent Relat Res 2001;3:185–193. 35. Oetterli M, Kiener P, Mericske-Stern R. A longitudinal study on mandibular implants supporting an overdenture: The influence of retention mechanism and anatomic-prosthetic variables on periimplant parameters. Int J Prosthodont 2001;14:536–542. 36. Morneburg TR, Proschel PA. Success rates of microimplants in edentulous patients with residual ridge resorption. Int J Oral Maxillofac Implants 2008;23:270–276. 37. Behneke A, Behneke N, d’Hoedt B. The longitudinal clinical effectiveness of ITI solid-screw implants in partially edentulous patients: A 5-year follow-up report. Int J Oral Maxillofac Implants 2000;15:633–645. 38. Albrektsson T, Zarb G, Worthington P, Eriksson AR. The longterm efficacy of currently used dental implants: A review and proposed criteria of success. Int J Oral Maxillofac Implants 1986; 1:11–25. 39. Zarb GA, Albrektsson T. Consensus report: Towards optimized treatment outcomes for dental implants. J Prosthet Dent 1998; 80:641. 40. Jeong SM, Choi BH, Li J, et al. Flapless implant surgery: An experimental study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:24–28. 41. Elsyad MA, Shoukouki AH. Resilient liner vs. clip attachment effect on peri-implant tissues of bar-implant-retained mandibular overdenture: A 1-year clinical and radiographical study. Clin Oral Implants Res 2010;21:473–480.

Literature Abstract Clinical orofacial characteristics associated with risk of first-onset TMD: The OPPERA prospective cohort study This comprehensive prospective cohort study of persons initially free of temporomandibular disorder (TMD) aimed to determine whether preclinical signs and symptoms and self-reported symptoms were able to predict subsequent development of TMD. Baseline self-reported status included pain, limitation of jaw use, orofacial symptoms other than pain (nonspecific), clicking, or locking. Baseline clinical status by examination included jaw mobility, temporomandibular joint (TMJ) noises, pain on palpation, and tooth wear. A total of 2,737 adults between 18 and 44 years of age were followed for a median of 2.8 years. Of these, 260 developed first-onset TMD. Significant predictors for TMD from baseline self-reported instruments were oral parafunctions, prior facial pain, TMJ noises and locking, and nonspecific orofacial symptoms. Significant predictors from baseline clinical examination were pain on jaw opening and pain on palpation of neck, masticatory, and body muscles. Examiner assessments of joint noises and wear facets did not predict TMD incidence. Mutivariable analysis identified nonspecific symptoms, pain on opening, and oral parafunctions as predictors of TMD. The results showed that TMD incidence was more reliably predicted by several self-reported orofacial characteristics than by examiner-assessed characteristics. Ohrbach R, Bair E, Fillingim RB, Gonzalez Y, Gordon SM, Lim PF, Ribeiro-DaSilva M, Diatchenko L, Dubner R, Greenspan JD, Knott C, Maixner W, Smith SB, Slade GD. J Pain 2013;14:T33–T50. References: 53. Reprints: Richard Ohrbach, Department of Oral Diagnostic Sciences, University at Buffalo, Buffalo, NY 14214, USA. Email: [email protected]—Steven Soo, Singapore

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The International Journal of Prosthodontics

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Immediate versus early loading of mini-implants supporting mandibular overdentures: a preliminary 3-year clinical outcome report.

The aim of this preliminary clinical report was to evaluate and compare the clinical outcomes of immediate and early loaded mini-implants (MIs) suppor...
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