eur j oral implantol 2008

Copyrightby

N

otfor

Qu

intessence

Not for Publication

Eur J Oral Implantol 2008;1(1):4551

45CLINICAL ARTICLE

Purpose: To evaluate the outcome of dental implants placed in partially edentulous patients with ahistory of severe periodontitis (SP), moderate periodontitis (MP) and no periodontitis (NP).Materials and methods: Sixty-two partially edentulous patients were consecutively enrolled in thisstudy. Patients were divided into three groups according to their initial periodontal conditions, assessed with a modified Periodontal Screening and Recording (PSR) index: 26 patients were in theSP group, 7 in the MP group, and 29 in the NP group. Patients requiring periodontal treatment weretreated prior to implantation. Various dental implants and procedures were used. In the SP group 129implants were placed, 26 were placed in the MP group, and 72 in the NP group. Outcome measureswere prosthetic success, implant survival, prevalence of peri-implantitis and mean peri-implant bonelevel changes on periapical radiographs. Results: Six patients dropped out, two from each group, at 5 years. Two implants and their prosthe-sis failed with peri-implantitis in one patient and two implants were successfully treated for peri-implantitis in another patient in the SP group. After 5 years, patients affected by SP and MP lost onaverage twice the amount of peri-implant bone compared with healthy patients (2.6 mm versus 1.2 mm). This difference was highly statistically significant.Conclusions: Patients with a history of SP and MP lose more peri-implant bone than periodontallyhealthy patients and might be at higher risk for peri-implantitis and implant failures.

Claudio Gatti, Fulvio Gatti, Matteo Chiapasco, Marco Esposito

Outcome of dental implants in partially edentulouspatients with and without a history of periodontitis:a 5-year interim analysis of a cohort study

bone level, dental implant, peri-implantitis, periodontitis, prognosisKey words

Claudio Gatti, MD, DDSPrivate practice,Parabiago and Milan, Italy

Fulvio Gatti, DDSTrainee, Specialty of Oral Surgery,Unit of Oral Surgery,Department of Medicine,Surgery and Dentistry,San Paolo Hospital,University of Milan,Milan, Italy

Matteo Chiapasco,MDHead Unit of Oral Surgery,Department of Medicine,Surgery and Dentistry,San Paolo Hospital,University of Milan,Milan, Italy

Marco Esposito, DDS, PhDSenior Lecturer, Oral andMaxillofacial Surgery,School of Dentistry,University of Manchester,UK

and Associate Professor,Department of Biomaterials,Sahlgrenska Academy atGteborg University,Sweden

Correspondence to:Dr Marco Esposito, School of Dentistry, Oral and MaxillofacialSurgery, University of Manchester,Higher Cambridge Street,Manchester M15 6FH, UKEmail: [email protected]

Introduction

Results from a recent systematic review suggestedthat patients with a previous history of periodontitisare at higher risk for peri-implantitis and peri-implantmarginal bone loss 5 years after loading when com-

pared with patients who had their teeth replaced byimplants for other reasons1. These results were basedonly on two studies with small sample sizes, both con-sidered at high risk for bias2,3. Therefore, the results ofthe systematic review should be interpreted with cau-tion. It was recommended to conduct further long-

Copyrightby

N

otfor

Qu

intessence

Not for Publication

term studies before final conclusions can be drawnabout the prognosis of implant treatment in patientswith a history of periodontitis1.

The aim of the present cohort study was to inves-tigate whether partially edentulous patients with a his-tory of severe periodontitis (SP) are at higher risk forimplant failures and peri-implantitis when comparedwith patients affected by moderate forms of periodon-titis (MP) or healthy ones (no periodontitis, NP). This isa preliminary 5-year report of a larger ongoing study.Future reports will be aimed at describing larger samplesizes with longer follow-up periods (10, 15 and 20years).

Materials and methods

This study was designed as a prospective cohortstudy with three arms, including consecutivelytreated partially edentulous patients. Follow-up was5 years after implant loading for all included patients.Treatments were carried out in two Italian privatedental practices between 1990 and 2002.

No ethical or institutional review board approvalwas sought. All procedures were performed by oneexperienced operator, except in one of the centreswhere another surgeon performed some implantplacement.

To be included, patients had to be 18 years orolder. Exclusion criteria were: edentulism in both jaws irradiation in the head and neck region, or

chemotherapy patients showing dubious cooperation unrealistic aesthetic expectations emotional instability and psychiatric problems substance abusers patients affected by HIV autoimmune diseases bone metabolic diseases uncontrolled diabetes serious coagulation problems pregnant or lactating women.

The following outcome measures were considered: Success of the prosthesis: a failed prosthesis or a

prosthesis that could not be placed due toimplant failure was considered a failure.

Implant survival: implants removed for any rea-sons were considered failures. Implant stabilitywas not assessed with the removed prosthesis.

Peri-implantitis: defined as loss of > 2 mm of peri-implant marginal bone from the last radiographicassessment, in the presence of pus or anothersign of infection and probing pocket depth > 5 mm.

Marginal bone level changes on periapical intra-oral radiographs made with the paralleling tech-nique: radiographs were taken at implant load-ing and after 5 years of loading. Measurementswere made by a single non-blinded calibratedassessor (CG, who treated and followed allpatients) using a magnifying ocular grid. Mea-surements of the mesial and distal bone crestlevel adjacent to each implant were made to thenearest 0.1 mm. Reference points for the linearmeasurements were the coronal margin of theimplant collar and the most coronal point ofbone-to-implant contact.

Description of the procedures

Periodontal therapy

At the first visit, the periodontal conditions wereassessed using a modification of the PeriodontalScreening and Recording (PSR) index4, and subse-quently periodontal therapy (non-surgical and surgi-cal) was administered as required (Table 1). The PSRindex is a modification of the Community PeriodontalIndex of Treatment Needs (CPITN), commissioned bythe World Health Organization to evaluate periodon-tal treatment needs in epidemiological studies5. ThePSR index added to the original CPITN coding systeman additional symbol code (*) denoting additionalperiodontal abnormities such as furcation involve-ment, tooth mobility, mucogingival defects and reces-sions. The following recording system was used onsextants and has five categories (wisdom teeth wereexcluded). Only the highest score was recorded foreach sextant:0 = healthy patient.1 = bleeding on probing.2 = presence of calculus and/or defective restora-

tions.3 = probing pocket depths between 3.5 to 5.5 mm

and/or furcation involvement degree 1


46 Gatti et al Implants in patients with a history of periodontitis

Copyrightby

N

otfor

Qu

intessence

Not for Publication

4 = probing pocket depths > 5.5 mm and/or furca-tion involvement degree 2 or more

Patients were divided into three groups according thefollowing characteristics: patients with PSR 02 wereconsidered healthy (NP group); patients with a PSR =3 were considered as affected by MP; and patientswith PSR = 4 were considered as affected by SP (Table1). The periodontal conditions of the patients atimplant placement (after periodontal therapy) are pre-sented in Table 1.

Implant placement

Implants were inserted according the guidelines ofthe various manufacturers. When required, variousbone augmentation procedures were implemented(Table 1). Implants from different manufacturers(Nobel Biocare [Gothenburg, Sweden], ZimmerDental [Carlsbad, CA, USA], Mathys [Bettlach,Switzerland], Straumann [Basel, Switzerland] andDentsply Friadent [Mannheim, Germany]), and withdifferent shapes and surface characteristics (Table 1)were used. After surgical procedures, patients were

instructed to use 0.2% chlorhexidine mouthwashes,starting 1 hour prior to the intervention, twice a dayfor 2 weeks.

Prosthetic and maintenance procedures

After an unloaded healing period ranging from 0 daysto 11 months (immediate loading procedures werealso implemented), abutments were connected andvarious types of prostheses (overdentures, fixed-crossarch prostheses, partial fixed bridges and singlecrowns) were placed. Patients of the SP group wererecalled for oral hygiene maintenance every 3 months,those in the MP group every 4 months, and those inthe NP group every 6 months.

Statistical analyses

All data analysis was carried out according to a pre-established analysis plan. The patient was the statisti-cal unit of the analyses. A biostatistician with expert-ise in dentistry analysed the data, without knowing thegroup allocation. Independent sample chi-square tests


47Gatti et al Implants in patients with a history of periodontitis

Severe periodontitis

Moderate periodontitis

No periodontitis

Number of patients 26 7 29

Number of patients with PSR = 02 at implant placement 20 6 29

Number of patients with PSR = 3 at implant placement 6 1 0

Mean age (range) at implant placement 56 (3585) 56 (4270) 40 (1861)

Number of females (%) 16 (62%) 3 (43%) 20 (69%)

Received surgical periodontal therapy (%) 18 (69%) 2 (29%) 0 (0%)

Smokers (%) 5 (19%) 3 (43%) 6 (20%)

Number of prostheses (failed) 48 (1) 9 (0) 38 (0)

Number of implants (failed) 129 (2) 26 (0) 72 (0)

Patients treated with machined surfaces (%) 15 (58%) 2 (29%) 20 (69%)

Implants affected by peri-implantitis (failed) 4 (2) 0 0

Implants in maxillae 48 9 38

Implants in anterior jaws* 59 4 33

Implants in augmented bone 17 7 15

Drop-outs at 5 years 2 2 2

Table 1 Patients maincharacteristics.

* Second to second premolar.

Copyrightby

N

otfor

Qu

intessence

Not for Publication

were to be used to compare the relative numbers ofpatients who had at least one prosthesis failure,implant failure or presence/absence of peri-implanti-tis. However, there were insufficient data for theseanalyses. The average radiographic values for themesial and distal surfaces were calculated and aver-aged for each patient. An analysis of variance wasused to compare mean bone level at 5 years and thechange in bone level for the three groups, followed byBonferroni test to make specific pairwise comparisons.Age was considered as a covariate in an analysis ofcovariance model. The Bonferroni test modified thecritical P-values for each comparison to achieve anoverall error rate of 0.05.

Results

Sixty-two partially edentulous patients were consecu-tively treated. After 5 years, six patients dropped out.

The SP group (Table 1; Figs 1a and 1b) consisted of26 patients, with a mean age of 56 years. At the timeof implant placement, after periodontal therapy, 20patients had a PRS index = 02, and six patients had aPSR index = 3 (Table 1). They received 129 implantssupporting 48 prostheses. Two patients dropped out 5years after loading: one moved but confirmed that allimplants were fine, and the other died.

The MP group (Table 1; Figs 2a and 2b) consistedof seven patients, with a mean age of 56 years. At thetime of implant placement, after periodontal therapy,

six patients had a PRS index = 02, and one patienthad a PSR index = 3 (Table 1). They received 26implants supporting nine prostheses. Two patientsdropped out 5 years after loading because of eco-nomic problems, but confirmed that all implants werefine; one patient was ill.

The NP group (Table 1) consisted of 29 patients,with a mean age of 40 years. At the time of implantplacement all patients had a PRS index = 02 (Table1). They received 72 implants supporting 38 prosthe-ses. Two patients dropped out 5 years after loading:one was not willing to attend the follow-up, but con-firmed that all implants were fine. The other patientwas no longer reachable.

One prosthesis was lost in the SP group: the twoanterior mandibular implants (Ha-Ti with an acid-etched sand-blasted surface, Mathys) supporting thisprosthesis failed because of peri-implantitis. Thoseimplants failed after 3 and 5 years respectively (Figs 3aand 3b). No therapy was delivered to save theseimplants because the bone loss was too advanced, andthe implants were removed. Two additional implants(MKIII with the TiUnite surface, Nobel Biocare) in theposterior mandible of another patient of the SP groupwere affected by peri-implantitis. They were treatedwith an apically repositioned flap, removal of theexposed threads, polishing of the implant surface, dis-infection with betadine, and systemic antibiotics (acocktail of amoxicillin and metronidazole for 10 days6).The implants were still in function at the 5-year follow-up. Both patients had a PSR index = 3 at the time of


48 Gatti et al Implants in patients with a history of periodontitis

Fig 1a Periapical radiograph showing peri-implant marginalbone levels just prior to implant loading of three two-piecetransmucosal implants in the maxilla of a patient belongingto the severe periodontitis group.

Fig 1b After 5 years of loading, bone loss up to the third tofourth thread can be observed around all implants, in theabsence of clinical symptoms.

Copyrightby

N

otfor

Qu

intessence

Not for Publication

implant placement and did not smoke. No other fail-ure or peri-implantitis occurred.

All radiographs could be evaluated at both themesial and distal site of each implant. Baseline, 5-year results and changes in bone level are shown forthe three study groups in Table 2. There were statis-tically significant differences in bone levels at 5 yearsand in change in bone level, with the healthy subjectshaving less bone loss than the other two groups (P

eur j oral implantol 2008

Documents