Isolation in Class V restorations

Today I had  3 restorations side by side that required different methods to restore. There was a 47 with large buccal caries that extended towards the mesial, a 45 with rampant caries that eventually covered the whole MODB, and a similarly carious 43. The oral hygiene was poor and the gingiva was very inflamed with subgingival carious margins. We are transitioning to a full denture.The challenges with each tooth and the restoration method were:

-47 subgingival margins, bleeding gingiva, poor access due to a high attachment of the buccinator muscle and hypertrophic masseters pushing the mucosa towards the tooth. For cheek retraction, dry tips could be used to ease handling, The mirror needs to be placed right against the gingiva at the mucobuccal fold and pull downwards and towards the bone not buccally. If you hold the mirror against the buccal mucosa and attempt to retract the cheek the mucosa will fold in and you won't have access to the tooth. Double large cords were placed before preparation. They are easy to place in inflamed gingiva but the lack of elasticity means they slip out very easily. If teflon was allowed at the hospital I would have forced a white teflon cord down the sulcus. The benefit of teflon is it is waterproof so won't allow gingival crevicular fluid to leak, doesn't have small tags of string that can be caught in the restoration and it provides much more vertical and horizontal retraction compared to cord. The method I used to prepare this tooth is the same as in a previous post: https://dental-tidbits.blogspot.com/2020/05/difficult-access-cavity-preparations.html. Restoraion involved overbulking the restoration and cutting it back.
-44, 43 inflamed, bleeding gingiva, need to form an interproximal contact. In this place, cord could have been placed and one tooth freehanded and cut back after set and the adjacent tooth built up with a matrix band against it. In this case, if there was cord placed it may still allow bleeding and fluid to flow past it. To simplify placement of the filling material, a tofflemire was used with the retainer on the lingual. To get the band to fit down against the cervical margin, the whole band has to be tilted downwards slightly and in patients with no perio pockets there will be significant digging of the band into the gingival attachment. Local anaesthetic has to be done very well. In this case I restored both teeth with a tofflemire and tightened it well. You will find if you don't apply enough apical pressure on the band while you tighten the knob it will tend to slip up over the cervical margin. Place a wedge and loosen a 1/4 turn. Due to the flare of the band the restoration will be overcontoured which is very handy to cut back after set. Squeeze in GIC and hold the matrix band wider while holding apical pressure on the band with your finger or it will slip off the tooth. Once it has set you can release the pressure, remove the wedge the carefully remove the band. The same method was then used to restore the 43. This method isn't as effective when only the buccal surface is involved i.e the cusp tips are intact as there is minimal opening into the cavity once the tofflemire is in place to flow the material.