Biologic and Technical Complications of Implant-Supported Immediately Loaded Fixed Full-Arch Prostheses: An Evaluation of Up to 6 Years

PURPOSE

Treatment by means of implant-supported immediately loaded fixed full-arch prostheses is known to be related to biologic and technical complications. The aim of this retrospective study was to investigate the prevalence and moment of occurrence of biologic and technical complications happening in immediately loaded fixed full-arch prostheses.

MATERIALS AND METHODS

This study investigated patients who received treatment with immediately loaded fixed full-arch prostheses using four to six implants from 2007 to 2013. The investigation included biologic and technical complications. Complications were depicted regarding their prevalence and their first time of occurrence. Statistical analysis was performed regarding the differences of the mean complication values between the mandible and the maxilla and between technical and biologic complications.

RESULTS

The investigation included 482 immediately loaded fixed full-arch prostheses (380 patients, mean observation period: 23.5 months). In 193 arches (40%), either technical (30.9%), biologic (6.5%), or both (3.1%) types of complications occurred. Technical complications occurred significantly more often than biologic complications (P < .000). The most frequent technical complication was "fracture of veneering material" (24.7%, arch level). The most frequent biologic complication was "marginal bone loss ≥ 2 mm" (16.3%, implant level). The median first advents of technical complications were after 23/26 months (implant-/prosthesis-related) and after 3 months for biologic complications, respectively. There was no significant difference of the mean complication rates between the maxilla and the mandible (P = .409). In 99.0% of the arches with complications, the restorations could be obtained.

CONCLUSION

Within this treatment concept, biologic and technical complications may occur over time. However, the vast majority of complications (99.0%) do not affect the overall prosthesis survival. Technical complications are assumed to occur significantly more often than biologic complications. It is suggested that not only stress and material fatigue but also function is a matter concerning this treatment option and, thus, may be a factor related to complication rates.

"Teflon tape technique": synergy between isolation and lucidity

The aim of this article is to introduce and illustrate the "Teflon tape technique," which provides good lucidity in combination with excellent isolation of the working field. It is intended to serve as a supplement to the gold standard rubber dam for the adhesive working dental practitioner. Primarily, the Teflon tape technique (Teflon is a registered trademark, and not affiliated with Teflon tape) is particularly suitable for the adhesive cementation of restorations with very thin margins. It allows free access to subgingival areas with variable gingival retraction. Furthermore, this principle can also be applied to other indications, such as Class V restorations or deep core buildups. The technique described is therefore flexible and easy to use. This combination allows a fast integration of the Teflon tape technique into the daily workflow of the dental practitioner.

Implant-Supported Immediately Loaded Fixed Full-Arch Dentures: Evaluation of Implant Survival Rates in a Case Cohort of up to 7 Years

BACKGROUND

The treatment of severely atrophied and edentulous jaws by means of fixed implant supported solutions is a challenging procedure.

PURPOSE

The immediate loading of four to six axial and tilted implants offers the possibility to overcome elaborate hard tissue augmentation procedures but lacks implant and patient related data on implant survival rates.

MATERIALS AND METHODS

This retrospective 7-years clinical trial investigated the implant survival rates of 2,081 implants (380 patients, 482 jaws) using an immediate loading protocol with either 4, 5, or 6 implants per restoration. Survival rates were calculated concerning implantation related factors (jaws/number of supporting implants/angulations/diameters/lengths) and patient related factors (medical status/smoking).

RESULTS

Overall survival of 2,081 implants was 97.0% on implant level. Survival rates of implantation related factors did not yield significant differences. Significant differences were yield between healthy patients and patients with osteoporosis (p = .002) and the medical status group "other" (p = .032), respectively. Smokers yielded a significantly higher survival than nonsmokers (p = .002).

CONCLUSIONS

It is assumed that four implants per jaw serve as a sufficient implant number for full arch restorations in both, the mandible and the maxilla. Osteoporosis under the medication with bisphosphonates seems to be a risk factor for implant survival. The authors suggest that the effect of smoking on ISRs remains controversial within this treatment concept.

Zygomatic implant placement in conjunction with sinus bone grafting: the "extended sinus elevation technique." a case-cohort study

PURPOSE

The zygomatic implant is mainly indicated for the rehabilitation of extremely atrophied maxillae when bone augmentation should be avoided. One drawback of zygomatic implants, which typically pass through the sinus, is initial or late bone resorption around the implant neck, which can result in oroantral communications followed by possible infection of the sinus. To decrease the risk of sinus infection, a modified technique was developed to preserve the integrity of the sinus membrane and to regenerate bone around zygomatic implants using an extended sinus grafting approach.

MATERIALS AND METHODS

Patients with extremely atrophied maxillae were provided with one to four zygomatic implants in conjunction with sinus grafting, plus conventional auxiliary implants, for immediate support of a provisional full-arch maxillary prosthesis. Definitive prostheses were delivered at 6 months after implant placement. All patients underwent clinical and radiographic examinations at 6 months.

RESULTS

Twenty-two zygomatic and 23 conventional auxiliary implants were placed in 10 patients. The overall 6-month implant survival rate was 90.9% for zygomatic implants and 100% for auxiliary implants placed in the anterior area. Only two minor technical complications were seen, and clinical indicators (including probing pocket depth, keratinized tissue, and plaque and bleeding indices) were good in all patients. A substantial gain of radiographic bone around the zygomatic implants was observed.

CONCLUSION

The proposed technique led to successful prosthetic function for all patients. With the described technique, exposed implant threads within the maxillary antrum are eliminated and the potential for biologic complications is minimized.

The bone lamina technique: a novel approach for lateral ridge augmentation--a case series

The goal of this case series is to present a novel treatment approach for lateral ridge augmentation. Four systemically healthy patients (aged 48 to 59 years) with inadequate dental alveolar ridge widths were selected for inclusion. All ridge defects were augmented using a xenogeneic cortical bone shield in combination with particulated bone substitutes and a thin collagen barrier. At baseline and after 6 months, digital cone beam computed tomography scans were performed. Biopsy specimens were harvested at reentry surgery and processed for histologic analysis. The results revealed a sufficient amount of bone structure for implant placement without additional augmentation procedures. The histologic analysis demonstrated that new bone formation had taken place and the bone shield had resorbed entirely. This case series indicates that the bone lamina technique has the biologic and mechanical properties to successfully achieve hard tissue augmentation of deficient ridges.

Immediate loading of fixed provisional prostheses using four implants for the rehabilitation of the edentulous arch: a prospective clinical study

PURPOSE

The purpose of this prospective clinical trial was to evaluate over a 5-year period the treatment outcomes for immediately loaded full-arch fixed prostheses supported by two axially inclined and two tilted implants used to rehabilitate edentulous arches. This report presents preliminary 1-year results.

MATERIALS AND METHODS

Thirty-seven patients were recruited for treatment with either mandibular or maxillary full-arch fixed prostheses supported by four implants. Within 24 hours, the implants were immediately loaded with screw-retained full-arch acrylic resin provisional restorations. Definitive reconstructions were delivered 6 months later. Complete full-arch prostheses were supported by metal frameworks combined with high-density acrylic resin. Follow-up visits were scheduled for 6 and 12 months after initial prosthetic loading and then annually for up to 5 years. Digital radiographs were obtained immediately, 6 months after surgery, and at each annual follow-up visit. Marginal peri-implant bone levels were assessed using digital image analysis.

RESULTS

The 1-year implant survival rates were 96.0% for axially positioned implants and 94.6% for tilted implants. The survival rates were 96.6% for maxillary implants and 98.7% for mandibular implants. The prosthetic survival rate was 100%. No significant differences were found in the results for tilted versus axially positioned implants. One year after loading, the mean marginal bone loss was 0.82 ± 0.31 mm around the axially oriented implants and 0.76 ± 0.49 mm around the tilted implants (P ⋜ .05).

CONCLUSIONS

Preliminary data from this clinical trial show high implant survival rates for immediately loaded full-arch prostheses supported by four implants. Immediate loading of tilted implants may be considered a viable treatment option for the rehabilitation of edentulous patients.

The Healing of Free Gingival Autografts for Socket-seal Surgery: a Case Report

Tooth extraction will be followed by marked alterations to the tissue volume, in particular in the anterior zone, which may jeopardize the esthetic outcome of any dental treatment involving tooth extraction. If, however, ridge collapse can eb prevented or minimized after tooth extraction, more predictable outcomes with superior esthetics can be accomplished along with fewer surgical procedures. Therefore, it was proposed that stabilizing the soft tissue architecture with a free gingival graft could minimize the soft tissue shrinkage. The following case report describes some surgical modifications and refinements in order to enhance the predictability of the socket-seal surgery.

The double split flap: a surgical approach for regenerative treatment of interproximal defects

AIMS AND BACKGROUND

Primary wound closure has been advocated to be indispensable for a successful outcome of guided tissue regeneration-procedures. Yet narrow inter-proximal spaces often lack sufficient tissue quantity in order to facilitate a tension free re-adaptation of periodontal flaps. In order to maintain an uneventful healing process, the concept of layer-wise wound closure is applied to periodontal surgery.

MATERIAL AND METHOD

This article describes the introduction of a modified flap design, the double split flap.

RESULTS AND CONCLUSION

By preparation of a second, internal flap and a wound in a layer-wise fashion, it is assumed that primary healing will be more predictable to achieve.

Hard tissue alterations after socket preservation: an experimental study in the beagle dog

OBJECTIVES

The aim of the following experimental study was to assess bone changes in the horizontal and vertical dimension when using different socket preservation procedures.

MATERIAL AND METHODS

In five beagle dogs the distal roots of the 3rd and 4th premolar were extracted without elevation of a mucoperiosteal flap and the following treatments were assigned: Tx 1: The extraction socket was filled with BioOss Collagen (Geistlich Biomaterials, Wolhusen, Switzerland) and interrupted sutures were applied.: Tx 2: The extraction socket was filled with BioOss Collagen (Geistlich Biomaterials, Wolhusen, Switzerland) and a free gingival graft was sutured to cover the socket.: Tx 3: The extraction socket was left with its blood clot and interrupted sututes were applied.: Four month after surgery the dogs were sacrificed and from each extraction site two histological sections were selected for histometric analysis. The following parameters were evaluated: (1) the vertical dimension was determined by placing a horizontal line on the lingual bone wall. Then, the distance from this line to the buccal bone wall was measured. (2) The horizontal dimension was assessed at three different areas measured from the top of the lingual crest: 1 mm (Value 1), 3 mm (Value 3) and 5 mm (Value 5).

RESULTS

The mean vertical loss of the buccal bone plate for the Tx 1 group was 2.8+/-0.2 mm. The Tx 2 group showed vertical loss of 3.3+/-0.2 mm. The Tx 3 group demonstrated 3.2+/-0.2 mm of mean vertical loss. The horizontal dimension of the alveolar process was 4.4+/-0.3/6.1+/-0.2/7.2+/-0.1 mm at the three different levels for the Tx 1 group. The Tx 2 group depicted bone dimensions of 4.8+/-0.2/6.0+/-0.2/7.1+/-0.1 mm. The horizontal dimension of the Tx 3 group was 3.7+/-0.3/6.2+/-0.2/7.0+/-0.1 mm. When the results from the horizontal measurements were tested with the analysis of variance (ANOVA), a clear significance could be found in particular for Value 1 mm between the test groups Tx 1 and Tx 2 and the control group (Tx 3) (P<0.001). Furthermore the mean of treatment 1 (Tx 1) was slightly significantly lower than of treatment 2 (Tx 2) (P<0.05).

CONCLUSION

The findings from the present study disclose that incorporation of BioOss Collagen into the extraction socket has only limited impact on the subsequent biologic process with particular respect to the buccal bone plate. The horizontal measurement of the alveolar ridge depicted that the loss of the buccal bone plate was replaced to a certain amount by newly generated bone guided by the BioOss Collagen scaffold. It seems that the mechanical stability provided by BioOss Collagen and furthermore by a free gingival graft could act as a placeholder preventing the soft tissue from collapsing.

The friction free osteotome technique: introduction of a modified approach

The current literature suggests that the bone-condensing approach while performing internal sinus floor elevation may not be beneficial for the future implant site. Furthermore, even with refined procedures, a predictable and controlled infraction of the sinus floor prior to graft placement still seems to be technique sensitive. In this context, the present article presents a modified technique along with the use of parallel osteotomes devoid of any contact to the lateral osteotomy wall. Therefore, compression of the adjacent bone will be avoided and the tactility of the site for the surgeon will be preserved as the osteotome is solely in contact with the subsinus cortex.

Tissue alterations after tooth extraction with and without surgical trauma: a volumetric study in the beagle dog

OBJECTIVES

The aim of this study is to evaluate whether tooth extraction without the elevation of a muco-periosteal flap has advantageous effects on the resorption rate after tooth extraction.

MATERIAL AND METHODS

In five beagle dogs polyether impressions were taken before the surgery. The roots of the first and second pre-molars (P(1) and P(2)) were extracted and the sites were assigned to one of the following treatments: treatment group (Tx) 1, no treatment; Tx 2, surgical trauma (flap elevation and repositioning); Tx 3, the extraction socket was filled with BioOss Collagen and closed with a free soft-tissue graft; Tx 4, after flap elevation and repositioning, the extraction socket was treated with BioOss Collagen and a free soft-tissue graft. Impressions were taken 2 and 4 months after surgery. The casts were scanned, matched together with baseline casts and evaluated with digital image analysis.

RESULTS

The "flapless groups" demonstrated significant lower resorption rates both when using socket-preservation techniques and without. Furthermore, socket-preservation techniques yielded better results compared with not treating the socket.

CONCLUSION

The results demonstrate that leaving the periosteum in place decreases the resorption rate of the extraction socket. Furthermore, the treatment of the extraction socket with BioOss Collagen and a free gingival graft seems beneficial in limiting the resorption process after tooth extraction.

Covering of gingival recessions with a modified microsurgical tunnel technique: case report

Recent advances in periodontal plastic surgery have encouraged reassessment of the envelope technique and its modified version, the tunnel technique, for root coverage. This article describes alterations in the technique-sensitive tunnel approach, which include an undermining split flap preparation of the buccal tissues with newly developed instruments to minimize trauma and ensure a better blood supply for the connective tissue graft. The use of a microsurgical concept, including microsurgical blades and suture material, improves wound healing and establishes a better esthetic result. Because these modifications simplify the tunnel approach, the spectrum of indications for the tunnel technique may be expanded and a broader application achieved.

Distraction osteogenesis: a treatment tool to improve baseline conditions for esthetic restorations on immediately placed dental implants--a case report

Replacement of two adjacent teeth in an anterior maxilla with deficient hard and soft tissues appears to be the utmost challenge in implant dentistry in the esthetic zone. In this case report, baseline conditions for implant placement were improved by alveolar distraction to enhance hard and soft tissues around the maxillary central incisors. Three months after the active phase of distraction, the roots of the central incisors were extracted and two screw-type dental implants were immediately placed into the extraction sockets. For immediate provisionalization, acrylic resin crowns were fabricated on UCLA abutments, providing the ideal emergence profile to support the periimplant soft tissue. Six months after implant placement, the prosthetic restoration of the case was finished with ceramic crowns cemented to individually fabricated zirconium oxide abutments. The described treatment strategy appears to have a great potential to restore natural esthetics in cases with major tissue deficiencies in the esthetic zone.

[Osseointegrated fixtures ad modum Brånemark--indications in the dental office]

Through the use of osseointegrated fixtures ad modum Brånemark we have the possibility to solve prosthetic problems. Three cases are described. They demonstrate that the use of osseointegrated fixtures combined with the concept of a reduced occlusal table can provide good functional stability.

The Hamburg short psychotherapy comparison experiment. The patient sample: overt and covert selection factors and prognostic predictions

(1) Our intake sample (n = 214) shows the well-known preponderance of upper-middle and middle class; however, in our case this selection is wholly independent from the influence of psychotherapists. Mean 'duration of problem' was over 10 years for 31% and from 5 to 10 years for another 18%. The intake sample deviated significantly in 'pathological' direction in every one of the 12 test scale means of the Freiburg Personality Inventory (FPI) from the population means. (2) Comparisons of the averse (i.e. to psychotherapy) subsample versus the affine group yielded cues that the former sample was a bit less ill and came from a less sophisticated background. The averse sample had a near normal arithmetic mean in 'verbal fluency' whereas its affine counter group was significantly higher. Therapy refusers (a subgroup of the averse) were less ill and had more often come 'on their own' than the 3 other subsamples. Therapy completers (a subgroup of the affine) were more often married and had a higher proportion of patients with a very long (10 years) 'duration of problem'. (3) Therapists' selection of candidates for psychotherapy operated through prognostic predictions for the intake sample. The prognoses of the CC predictors were significantly more optimistic than those of the PT prognosticians. In regard to psychological tests both CC and PT prognostically favoured 'manifest anxious' and 'inhibited' (socially anxious) patients. This communal nucleus is expanded for PT to include less sociable but not undercontrolled patients, whereas CC prognosticians favoured depressed, inferior feeling, but more verbally intelligent patients with less psychosomatic instability. Thus, except perhaps for the CC therapists preferring verbal intelligence, our prognosticians resisted the famous attraction of the YAVIS patient (Y = young, A = attractive, V = verbal, I = intelligent, S = successful) [Goldstein, 1977 p. 6]. (4) Lot assignment achieved a random distribution. There is a nonsignificant tendency for the immediate therapy sample to be a bit more disturbed than the waiting group. The patients filling out session questionnaires might be a bit more disturbed than those not asked to fill these in.