Prolene hernia system, ultrapro hernia system and 3D patch devices in the treatment of inguinal, femoral, umbilical and small incisional hernias in outpatient surgery.

INTRODUCTION: The employment of a diversity of prosthetic materials and several types of mesh different in construction is opening a new chapter in hernia surgery and tension-free techniques are becoming a "golden standard" for repairing abdominal wall defects, whereas the conventional methods, i.e., the tension techniques are performed on young patients having small direct, indirect, or femoral hernias. AIM: The aim of this retrospective study is to present the results of using Prolene Hernia System (PHS), Ultrapro Hernia System (UHS) and 3D Patch (3DP) devices in the treatment of inguinal, femoral, umbilical and small incisional hernias in outpatient surgery. MATERIAL AND METHODS: From January 2006 to January 2009, 70 patients were operated on for abdominal wall hernias (54 inguinal, 4 femoral, 8 umbilical and 4 small incisional hernias) using PHS, UHS and 3DP devices. All the patients underwent surgery under local infiltrative anaesthesia. All the surgical operations were performed by a single surgeon, 19 of them in the General Hospital and 51 in a private polyclinic. RESULTS: The mean size of the hernia defect in the inguinal, femoral and umbilical hernias was 2.5 cm (1-4 cm), while in the incisional hernias it was 4.5 cm (3-6 cm). The mean operating time was 2.4 hrs (2-6 hrs). There were no requirement for urinary drains. The mean follow-up was 18 months (0-36 months). The incidence of infection, chronic pain and recurrence was 0%. Three of the patients had complications: seroma in one patient with an incisional hernia and hematoma in two patients after inguinal hernia repair. CONCLUSION: The employment of PHS, UHS and 3DP devices, which have not yet been widely accepted in our hospitals, has had outstanding results in outpatient surgery. In addition, the type of anaesthesia and the 3D mesh construction prepare the way for a short hospital stay, smooth recovery and a swift return to normal activity.

An SEM examination of etched dentin and the structure of the hybrid layer.

The clinical requirements of dentin bonds are that they should be non-permeable to oral fluids, seal dentinal tubules, protect the pulp, and be long lasting and durable. Dentin bonding systems that use acidic agents to remove the smear layer are currently being used. Acid conditioning not only removes the smear layer, but also demineralizes the surface of the intertubular dentin and produces intratubular demineralization and funnelling. A dentin bond is produced when hydrophillic resin monomers infiltrate the dentinal tubules and collagen of the demineralized intertubular zone, producing a hybrid layer. The use of a critical point drying technique and SEM allows a clear visualization of the structure of the hybrid layer. This study showed that currently used hydrophillic resin monomers are unable to completely infiltrate the demineralized zone, and it is speculated that this failure could contribute to microleakage and influence the long-term durability of the bond. It is also apparent that these bonds depend on the mechanical investment of collagen by the infiltrating monomer. Since none of the unfilled resins tested seem capable of completely infiltrating the demineralized collagenous zone, the degree of demineralization produced by the commercial acid concentrations in current use is questioned. More dilute acids than those available commercially are shown to reduce both the degree and depth of demineralization, and we suggest that the resultant thinner layer may lend itself to more complete resin infiltration of the collagen.

Penetration of a dentin bonding agent into dentin.

PURPOSE: To examine how the priming agents of Scotchbond Multi-Purpose (SMP) influenced the wettability of collagen in the demineralized zone and hence the penetration and adaptation of its bonding monomers. MATERIALS AND METHODS: Freshly extracted bovine teeth were ground to dentin with SiC paper. SMP and Z100 resin were used. Shear bond testing was performed as well as scanning electron microscopic evaluation. RESULTS: In contrast to the manufacturer's instructions, a 26.3% increase in shear bond strength was obtained when a second coat of priming agent was applied. This increase was statistically significant at the 5% level of confidence. SEM examination of failed conventionally air dried (CAD) specimens showed the presence of voids in the demineralized layer. SEM examination of failed specimens prepared by a critical point drying (CPD) technique showed that these voids were filled with collagen fibrils. The CPD technique also clearly showed that collagen fibrils were incorporated in the unfilled resin. Although priming agents appear to facilitate the penetration of unfilled resin into the demineralized layer and the dentin tubules, areas of unincorporated collagen fibrils can be seen even after two or more applications of the priming agent.

The morphology of the demineralized layer in primed dentin.

This study critically examined the surface and subsurface effects of selected dentin priming agents. Various dentin priming agents were used and specimens were prepared for SEM examination by conventional air drying or by a freeze fracture and critical point drying technique. The results showed that in specimens prepared by freeze fracture and critical point drying technique the demineralization of the dentin surface and subsurface by priming agents leaves a visible network of collagen fibrils. This technique allows better evaluation of the adaptation of bonding resins to the collagen network of the demineralized layer.

Fracture toughness of dental composites determined using the short-rod fracture toughness test.

Plane strain fracture toughness (KIC) has been evaluated for a number of commercially-available dental composites. A modified Short-rod Fracture Toughness (SRFT) specimen design has been used, enabling small specimens to be tested conveniently. The effect on KIC of aging in water at 37 degrees C for seven days, one month, and six months has been determined for conventional, microfilled, and hybrid (coarse and fine filler particle-containing) composites. Our results suggest that aging for one month or more caused a reduction of KIC for the composites so aged. Comparison of the KIC values determined using the modified SRFT specimen with values obtained using more conventional specimen geometries gave good agreement, thereby suggesting the suitability of the small SRFT specimens for valid KIC determinations.

Oscillatory wear tests of dental composites.

The wear behavior of 12 commercial restorative composites (conventional and microfilled) and an unfilled restorative material was evaluated using an in vitro wear test referred to as an oscillatory wear test. The effect of varying test conditions was evaluated in a series of preliminary experiments in order to define test conditions for material evaluation. The materials were tested after being aged in water at 37 degrees C for periods of from seven days to one year. The results indicated consistently lower wear rates for the microfilled materials as compared with those of the conventional composites. Aging did not result in significant differences in wear rates measured by this method. Scanning electron micrography of worn surfaces suggested a possible effect of filler particle shape and bonding to the matrix to explain this difference. Although the relevance of the results to clinical behavior is not yet known, the study indicated the importance of material variables on wear.